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- heart failure (16)
- echocardiography (9)
- Herzinsuffizienz (8)
- cardiomyopathy (6)
- magnetic resonance imaging (6)
- mitochondria (6)
- acute heart failure (5)
- myocardial infarction (5)
- prognosis (5)
- akute Herzinsuffizienz (4)
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- Deutsches Zentrum für Herzinsuffizienz (DZHI) (155) (entfernen)
Sonstige beteiligte Institutionen
- Clinical Trial Center (CTC) / Zentrale für Klinische Studien Würzburg (ZKSW) (2)
- Center for Interdisciplinary Clinical Research, Würzburg University, Würzburg, Germany (1)
- Datenintegrationszentrum Würzburg (DIZ) (1)
- Department of Medicinal Chemistry, University of Vienna, Althanstraße 14, 1090 Vienna, Austria (1)
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria (1)
- Interdisziplinäre Biomaterial- und Datenbank Würzburg (ibdw) (1)
- Interdisziplinäre Zentrum für Klinische Forschung (IZKF) (1)
- Interdisziplinäres Zentrum für Klinische Forschung (IZKF) (1)
- Klinische Studienzentrale (Universitätsklinikum) (1)
- Servicezentrum Medizin-Informatik (1)
The blood-air barrier in the lung consists of the alveolar epithelium, the underlying capillary endothelium, their basement membranes and the interstitial space between the cell layers. Little is known about the interactions between the alveolar and the blood compartment. The aim of the present study was to gain first insights into the possible interplay between these two neighboured cell layers. We established an in vitro Transwell model of the alveolar epithelium based on human cell line H441 and investigated the influence of conditioned medium obtained from human lung endothelial cell line HPMEC-ST1.6R on the barrier properties of the H441 layers. As control for tissue specificity H441 layers were exposed to conditioned medium from human brain endothelial cell line hCMEC/D3. Addition of dexamethasone was necessary to obtain stable H441 cell layers. Moreover, dexamethasone increased expression of cell type I markers (caveolin-1, RAGE) and cell type II marker SP-B, whereas decreased the transepithelial electrical resistance (TEER) in a concentration dependent manner. Soluble factors obtained from the lung endothelial cell line increased the barrier significantly proven by TEER values and fluorescein permeability on the functional level and by the differential expression of tight junctional proteins on the molecular level. In contrast to this, soluble factors derived from brain endothelial cells weakened the barrier significantly. In conclusion, soluble factors from lung endothelial cells can strengthen the alveolar epithelium barrier in vitro, which suggests communication between endothelial and epithelial cells regulating the integrity of the blood-air barrier.
Background Data on cardiovascular diseases (CVD) and cognitive decline are conflicting. Our objective was to investigate if CVD is associated with an increased risk for cognitive decline and to examine whether hypertension, diabetes, or adiposity modify the effect of CVD on cognitive functioning.
Methods and Results: Prospective follow‐up of 6455 cognitively intact, postmenopausal women aged 65 to 79 years old enrolled in the Women's Health Initiative Memory Study (WHIMS). CVD was determined by self‐report. For cognitive decline, we assessed the incidence of mild cognitive impairment (MCI) or probable dementia (PD) via modified mini‐mental state examination (3 MS) score, neurocognitive, and neuropsychiatric examinations. The median follow‐up was 8.4 years. Women with CVD tended to be at increased risk for cognitive decline compared with those free of CVD (hazard ratio [HR], 1.29; 95% CI: 1.00, 1.67). Women with myocardial infarction or other vascular disease were at highest risk (HR, 2.10; 95% CI: 1.40, 3.15 or HR, 1.97; 95% CI: 1.34, 2.87). Angina pectoris was moderately associated with cognitive decline (HR 1.45; 95% CI: 1.05, 2.01) whereas no significant relationships were found for atrial fibrillation or heart failure. Hypertension and diabetes increased the risk for cognitive decline in women without CVD. Diabetes tended to elevate the risk for MCI/PD in women with CVD. No significant trend was seen for adiposity.
Conclusions: CVD is associated with cognitive decline in elderly postmenopausal women. Hypertension and diabetes, but not adiposity, are associated with a higher risk for cognitive decline. More research is warranted on the potential of CVD prevention for preserving cognitive functioning.
Functional magnetic resonance imaging (fMRI) has become a powerful and influential method to non-invasively study neuronal brain activity. For this purpose, the blood oxygenation level-dependent (BOLD) effect is most widely used. T2* weighted echo planar imaging (EPI) is BOLD sensitive and the prevailing fMRI acquisition technique. Here, we present an alternative to its standard Cartesian recordings, i.e. k-space density weighted EPI, which is expected to increase the signal-to-noise ratio in fMRI data. Based on in vitro and in vivo pilot measurements, we show that fMRI by k-space density weighted EPI is feasible and that this new acquisition technique in fact boosted spatial and temporal SNR as well as the detection of local fMRI activations. Spatial resolution, spatial response function and echo time were identical for density weighted and conventional Cartesian EPI. The signal-to-noise ratio gain of density weighting can improve activation detection and has the potential to further increase the sensitivity of fMRI investigations.
Multiple activities are ascribed to the cytokine tumor necrosis factor (TNF) in health and disease. In particular, TNF was shown to affect carcinogenesis in multiple ways. This cytokine acts via the activation of two cell surface receptors, TNFR1, which is associated with inflammation, and TNFR2, which was shown to cause anti-inflammatory signaling. We assessed the effects of TNF and its two receptors on the progression of pancreatic cancer by in vivo bioluminescence imaging in a syngeneic orthotopic tumor mouse model with Panc02 cells. Mice deficient for TNFR1 were unable to spontaneously reject Panc02 tumors and furthermore displayed enhanced tumor progression. In contrast, a fraction of wild type (37.5%), TNF deficient (12.5%), and TNFR2 deficient mice (22.2%) were able to fully reject the tumor within two weeks. Pancreatic tumors in TNFR1 deficient mice displayed increased vascular density, enhanced infiltration of CD4+ T cells and CD4+ forkhead box P3 (FoxP3)+ regulatory T cells (Treg) but reduced numbers of CD8+ T cells. These alterations were further accompanied by transcriptional upregulation of IL4. Thus, TNF and TNFR1 are required in pancreatic ductal carcinoma to ensure optimal CD8+ T cell-mediated immunosurveillance and tumor rejection. Exogenous systemic administration of human TNF, however, which only interacts with murine TNFR1, accelerated tumor progression. This suggests that TNFR1 has basically the capability in the Panc02 model to trigger pro-and anti-tumoral effects but the spatiotemporal availability of TNF seems to determine finally the overall outcome.
Background: Impairments of health related quality of life (HRQoL) are frequently observed in Fabry disease (FD) and are known to be related to neuropathic pain and cardiovascular events. This study aimed to explore the role of chronic kidney disease (CKD) in a large cohort of patients with FD.
Methods: In 96 patients (53% female; age 40 ± 12 yrs) with genetically proven FD, HRQoL was assessed by the Medical Outcomes Study (SF-36) questionnaire. All patients were naïve to enzyme replacement therapy. Three categories for kidney dysfunction were chosen, eGFR ≥/<60 ml/min/1.73 m2 or need of renal replacement therapy (RRT). Minor (e.g. arrhythmia, angina pectoris, etc.) and major (e.g. myocardial infarction, coronary artery bypass, stroke or implantable cardioverter-defibrillator) vascular events as well as pain and pain therapy were considered in linear regression analyses with the dimensions of HRQoL.
Results: Ten patients (10%) had impaired kidney function and a further nine were on RRT (9.4%). Kidney function and pain emerged as the main factors associated with lower scores on the SF 36, in particular on physical components (PCS beta-coefficients for CKD −6.2, for RRT −11.8, for pain −9.1, p < 0.05, respectively), while controlling for gender, vascular event and pain-therapy. Relationships were found for mental aspects of HRQoL. Age and history of vascular events were not related to HRQoL.
Conclusion: Cardiovascular events and pain are important factors related to HRQoL, social functioning and depression. Our study highlights impaired chronic kidney disease, in particular after initiation of RRT, as a strong determinant of reduced HRQoL in FD.
Objectives: Since diastolic abnormalities are typical findings of cardiac amyloidosis (CA), we hypothesized that speckle-tracking-imaging (STI) derived longitudinal early diastolic strain rate (LSRdias) could predict outcome in CA patients with preserved left ventricular ejection fraction (LVEF >50%).
Background: Diastolic abnormalities including altered early filling are typical findings and are related to outcome in CA patients. Reduced longitudinal systolic strain (LSsys) assessed by STI predicts increased mortality in CA patients. It remains unknown if LSRdias also related to outcome in these patients.
Methods: Conventional echocardiography and STI were performed in 41 CA patients with preserved LVEF (25 male; mean age 65±9 years). Global and segmental LSsys and LSRdias were obtained in six LV segments from apical 4-chamber views.
Results: Nineteen (46%) out of 41 CA patients died during a median of 16 months (quartiles 5–35 months) follow-up. Baseline mitral annular plane systolic excursion (MAPSE, 6±2 vs. 8±3 mm), global LSRdias and basal-septal LSRdias were significantly lower in non-survivors than in survivors (all p<0.05). NYHA class, number of non-cardiac organs involved, MAPSE, mid-septal LSsys, global LSRdias, basal-septal LSRdias and E/LSRdias were the univariable predictors of all-cause death. Multivariable analysis showed that number of non-cardiac organs involved (hazard ratio [HR] = 1.96, 95% confidence interval [CI] 1.17–3.26, P = 0.010), global LSRdias (HR = 7.30, 95% CI 2.08–25.65, P = 0.002), and E/LSRdias (HR = 2.98, 95% CI 1.54–5.79, P = 0.001) remained independently predictive of increased mortality risk. The prognostic performance of global LSRdias was optimal at a cutoff value of 0.85 S−1 (sensitivity 68%, specificity 67%). Global LSRdias <0.85 S−1 predicted a 4-fold increased mortality in CA patients with preserved LVEF.
Conclusions: STI-derived early diastolic strain rate is a powerful independent predictor of survival in CA patients with preserved LVEF.
The Quality of Acute Stroke Care-an Analysis of Evidence-Based Indicators in 260 000 Patients
(2014)
Background: Stroke patients should be cared for in accordance with evidence-based guidelines. The extent of implementation of guidelines for the acute care of stroke patients in Germany has been unclear to date. Methods: The regional quality assurance projects that cooperate in the framework of the German Stroke Registers Study Group (Arbeitsgemeinschaft Deutscher Schlaganfall-Register, ADSR) collected data on the care of stroke patients in 627 hospitals in 2012. The quality of the acute hospital care of patients with stroke or transient ischemic attack (TIA) was assessed on the basis of 15 standardized, evidence-based quality indicators and compared across the nine participating regional quality assurance projects. Results: Data were obtained on more than 260 000 patients nationwide. Intravenous thrombolysis was performed in 59.7% of eligible ischemic stroke patients patients (range among participating projects, 49.7-63.6%). Dysphagia screening was documented in 86.2% (range, 74.8-93.1%). For the following indicators, the defined targets were not reached for all of Germany: antiaggregation within 48 hours, 93.4% (range, 86.6-96.4%); anticoagulation for atrial fibrillation, 77.6% (range, 72.4-80.1%); standardized dysphagia screening, 86.2% (range, 74.8-93.1%); oral and written information of the patients or their relatives, 86.1% (range, 75.4-91.5%). The rate of patients examined or treated by a speech therapist was in the target range. Conclusion: The defined targets were reached for most of the quality indicators. Some indicators, however, varied widely across regional quality assurance projects. This implies that the standardization of care for stroke patients in Germany has not yet been fully achieved.
Background
Prospective data examining the relationship between dietary protein intake and incident coronary heart disease (CHD) are inconclusive. Most evidence is derived from homogenous populations such as health professionals. Large community-based analyses in more diverse samples are lacking.
Methods
We studied the association of protein type and major dietary protein sources and risk for incident CHD in 12,066 middle-aged adults (aged 45–64 at baseline, 1987–1989) from four U.S. communities enrolled in the Atherosclerosis Risk in Communities (ARIC) Study who were free of diabetes mellitus and cardiovascular disease at baseline. Dietary protein intake was assessed at baseline and after 6 years of follow-up by food frequency questionnaire. Our primary outcome was adjudicated coronary heart disease events or deaths with following up through December 31, 2010. Cox proportional hazard models with multivariable adjustment were used for statistical analyses.
Results
During a median follow-up of 22 years, there were 1,147 CHD events. In multivariable analyses total, animal and vegetable protein were not associated with an increased risk for CHD before or after adjustment. In food group analyses of major dietary protein sources, protein intake from red and processed meat, dairy products, fish, nuts, eggs, and legumes were not significantly associated with CHD risk. The hazard ratios [with 95% confidence intervals] for risk of CHD across quintiles of protein from poultry were 1.00 [ref], 0.83 [0.70–0.99], 0.93 [0.75–1.15], 0.88 [0.73–1.06], 0.79 [0.64–0.98], P for trend = 0.16). Replacement analyses evaluating the association of substituting one source of dietary protein for another or of decreasing protein intake at the expense of carbohydrates or total fats did not show any statistically significant association with CHD risk.
Conclusion
Based on a large community cohort we found no overall relationship between protein type and major dietary protein sources and risk for CHD.
Background
The role of the immune system in the pathophysiology of acute ischemic stroke is increasingly recognized. However, targeted treatment strategies to modulate immunological pathways in stroke are still lacking. Glatiramer acetate is a multifaceted immunomodulator approved for the treatment of relapsing-remitting multiple sclerosis. Experimental studies suggest that glatiramer acetate might also work in other neuroinflammatory or neurodegenerative diseases apart from multiple sclerosis.
Findings
We evaluated the efficacy of glatiramer acetate in a mouse model of brain ischemia/reperfusion injury. 60 min of transient middle cerebral artery occlusion was induced in male C57Bl/6 mice. Pretreatment with glatiramer acetate (3.5 mg/kg bodyweight) 30 min before the induction of stroke did not reduce lesion volumes or improve functional outcome on day 1.
Conclusions
Glatiramer acetate failed to protect from acute ischemic stroke in our hands. Further studies are needed to assess the true therapeutic potential of glatiramer acetate and related immunomodulators in brain ischemia.
Background
Fatty acid binding protein (FABP) is an intracellular transport protein associated with myocardial damage size in patients undergoing cardiac surgery. Furthermore, elevated FABP serum concentrations are related to a number of common comorbidities, such as heart failure, chronic kidney disease, diabetes mellitus, and metabolic syndrome, which represent important risk factors for postoperative acute kidney injury (AKI). Data are lacking on the association between preoperative FABP serum level and postoperative incidence of AKI.
Methods
This prospective cohort study investigated the association between preoperative h-FABP serum concentrations and postoperative incidence of AKI, hospitalization time and length of ICU treatment. Blood samples were collected according to a predefined schedule. The AKI Network definition of AKI was used as primary endpoint. All associations were analysed using descriptive and univariate analyses.
Results
Between 05/2009 and 09/2009, 70 patients undergoing cardiac surgery were investigated. AKI was observed in 45 patients (64%). Preoperative median (IQR) h-FABP differed between the AKI group (2.9 [1.7–4.1] ng/ml) and patients without AKI (1.7 [1.1–3.3] ng/ml; p = 0.04), respectively. Patients with AKI were significantly older. No statistically significant differences were found for gender, type of surgery, operation duration, CPB-, or X-Clamp time, preoperative cardiac enzymes, HbA1c, or CRP between the two groups. Preoperative h-FABP was also correlated with the length of ICU stay (rs = 0.32, p = 0.007).
Conclusions
We found a correlation between preoperative serum h-FABP and the postoperative incidence of AKI. Our results suggest a potential role for h-FABP as a biomarker for AKI in cardiac surgery.
Healthy Dietary Interventions and Lipoprotein (a) Plasma Levels: Results from the Omni Heart Trial
(2014)
Background: Increased lipoprotein(a) [Lp(a)] levels are associated with atherosclerotic cardiovascular disease. Studies of dietary interventions on changes in Lp(a) are sparse. We aimed to compare the effects of three healthy dietary interventions differing in macronutrient content on Lp(a) concentration.
Methods: Secondary analysis of a randomized, 3-period crossover feeding study including 155 (89 blacks; 66 whites) individuals. Participants were given DASHtype healthy diets rich in carbohydrates [Carb], in protein [Prot] or in unsaturated fat [Unsat Fat] for 6 weeks each. Plasma Lp(a) concentration was assessed at baseline and after each diet.
Results: Compared to baseline, all interventional diets increased mean Lp(a) by 2 to 5 mg/dl. Unsat Fat increased Lp(a) less than Prot with a difference of 1.0 mg/dl (95% CI, -0.5, 2.5; p=0.196) in whites and 3.7 mg/dl (95% CI, 2.4, 5.0; p<0.001) in blacks (p-value between races=0.008); Unsat Fat increased Lp(a) less than Carb with a difference of 20.6 mg/dl, 95% CI, -2.1, 0.9; p=0.441) in whites and 21.5 mg/dl (95% CI, -0.2, -2.8; p=0.021) in blacks (p-value between races=0.354). Prot increased Lp(a) more than Carb with a difference of 0.4 mg/dl (95% CI, -1.1, 1.9; p=0.597) in whites and 2.2 mg/dl (95%CI, 0.9, 3.5; p=0.001) in blacks (p-value between races=0.082).
Conclusion: Diets high in unsaturated fat increased Lp(a) levels less than diets rich in carbohydrate or protein with greater changes in blacks than whites. Our results suggest that substitutions with dietary mono- and polyunsaturated fatty acids in healthy diets may be preferable over protein or carbohydrates with regards to Lp(a).
Background: Designing treatment strategies for unruptured giant intracranial aneurysms (GIA) is difficult as evidence of large clinical trials is lacking. We examined the outcome following surgical or endovascular GIA treatment focusing on patient age, GIA location and unruptured GIA. Methods: Medline and Embase were searched for studies reporting on GIA treatment outcome published after January 2000. We calculated the proportion of good outcome (PGO) for all included GIA and for unruptured GIA by meta-analysis using a random effects model. Results: We included 54 studies containing 64 study populations with 1,269 GIA at a median follow-up time (FU-T) of 26.4 months (95% CI 10.8-42.0). PGO was 80.9% (77.4-84.4) in the analysis of all GIA compared to 81.2% (75.3-86.1) in the separate analysis of unruptured GIA. For each year added to patient age, PGO decreased by 0.8%, both for all GIA and unruptured GIA. For all GIA, surgical treatment resulted in a PGO of 80.3% (95% CI 76.0-84.6) compared to 84.2% (78.5-89.8, p = 0.27) after endovascular treatment. In unruptured GIA, PGO was 79.7% (95% CI 71.5-87.8) after surgical treatment and 84.9% (79.1-90.7, p = 0.54) after endovascular treatment. PGO was lower in high quality studies and in studies presenting aggregate instead of individual patient data. In unruptured GIA, the OR for good treatment outcome was 5.2 (95% CI 2.0-13.0) at the internal carotid artery compared to 0.1 (0.1-0.3, p < 0.1) in the posterior circulation. Patient sex, FU-T and prevalence of ruptured GIA were not associated with PGO. Conclusions: We found that the chances of good outcome after surgical or endovascular GIA treatment mainly depend on patient age and aneurysm location rather than on the type of treatment conducted. Our analysis may inform future research on GIA.
Objective:
Traumatic brain injury is a major global public health problem for which specific therapeutic interventions are lacking. There is, therefore, a pressing need to identify innovative pathomechanism-based effective therapies for this condition. Thrombus formation in the cerebral microcirculation has been proposed to contribute to secondary brain damage by causing pericontusional ischemia, but previous studies have failed to harness this finding for therapeutic use. The aim of this study was to obtain preclinical evidence supporting the hypothesis that targeting factor XII prevents thrombus formation and has a beneficial effect on outcome after traumatic brain injury.
Methods:
We investigated the impact of genetic deficiency of factor XII and acute inhibition of activated factor XII with a single bolus injection of recombinant human albumin-fused infestin-4 (rHA-Infestin-4) on trauma-induced microvascular thrombus formation and the subsequent outcome in 2 mouse models of traumatic brain injury.
Results:
Our study showed that both genetic deficiency of factor XII and an inhibition of activated factor XII in mice minimize trauma-induced microvascular thrombus formation and improve outcome, as reflected by better motor function, reduced brain lesion volume, and diminished neurodegeneration. Administration of human factor XII in factor XII-deficient mice fully restored injury-induced microvascular thrombus formation and brain damage.
Interpretation:
The robust protective effect of rHA-Infestin-4 points to a novel treatment option that can decrease ischemic injury after traumatic brain injury without increasing bleeding tendencies.
Aims
We previously reported that in the EMPA-REG OUTCOME(R) trial, empagliflozin added to standard of care reduced the risk of 3-point major adverse cardiovascular events, cardiovascular and all-cause death, and hospitalization for heart failure in patients with type 2 diabetes and high cardiovascular risk. We have now further investigated heart failure outcomes in all patients and in subgroups, including patients with or without baseline heart failure.
Methods and results
Patients were randomized to receive empagliflozin 10 mg, empagliflozin 25 mg, or placebo. Seven thousand and twenty patients were treated; 706 (10.1%) had heart failure at baseline. Heart failure hospitalization or cardiovascular death occurred in a significantly lower percentage of patients treated with empagliflozin 265/4687 patients (5.7%)] than with placebo 198/2333 patients (8.5%)] hazard ratio, HR: 0.66 (95% confidence interval: 0.55-0.79); P < 0.001], corresponding to a number needed to treat to prevent one heart failure hospitalization or cardiovascular death of 35 over 3 years. Consistent effects of empagliflozin were observed across subgroups defined by baseline characteristics, including patients with vs. without heart failure, and across categories of medications to treat diabetes and/or heart failure. Empagliflozin improved other heart failure outcomes, including hospitalization for or death from heart failure 2.8 vs. 4.5%; HR: 0.61 (0.47-0.79); P < 0.001] and was associated with a reduction in all-cause hospitalization 36.8 vs. 39.6%; HR: 0.89 (0.82-0.96); P = 0.003]. Serious adverse events and adverse events leading to discontinuation were reported by a higher proportion of patients with vs. without heart failure at baseline in both treatment groups, but were no more common with empagliflozin than with placebo.
Conclusion
In patients with type 2 diabetes and high cardiovascular risk, empagliflozin reduced heart failure hospitalization and cardiovascular death, with a consistent benefit in patients with and without baseline heart failure.
Objective: This clinical practice guideline addresses the diagnosis and treatment of primary adrenal insufficiency. Participants: The Task Force included a chair, selected by The Clinical Guidelines Subcommittee of the Endocrine Society, eight additional clinicians experienced with the disease, a methodologist, and a medical writer. The co-sponsoring associations (European Society of Endocrinology and the American Association for Clinical Chemistry) had participating members. The Task Force received no corporate funding or remuneration in connection with this review. Evidence: This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to determine the strength of recommendations and the quality of evidence.
Consensus Process: The evidence used to formulate recommendations was derived from two commissioned systematic reviews as well as other published systematic reviews and studies identified by the Task Force. The guideline was reviewed and approved sequentially by the Endocrine Society's Clinical Guidelines Subcommittee and Clinical Affairs Core Committee, members responding to a web posting, and the Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.
Conclusions: We recommend diagnostic tests for the exclusion of primary adrenal insufficiency in all patients with indicative clinical symptoms or signs. In particular, we suggest a low diagnostic (and therapeutic) threshold in acutely ill patients, as well as in patients with predisposing factors. This is also recommended for pregnant women with unexplained persistent nausea, fatigue, and hypotension. We recommend a short corticotropin test (250 mu g) as the "gold standard" diagnostic tool to establish the diagnosis. If a short corticotropin test is not possible in the first instance, we recommend an initial screening procedure comprising the measurement of morning plasma ACTH and cortisol levels. Diagnosis of the underlying cause should include a validated assay of autoantibodies against 21-hydroxylase. In autoantibody-negative individuals, other causes should be sought. We recommend once-daily fludrocortisone (median, 0.1 mg) and hydrocortisone (15-25 mg/d) or cortisone acetate replacement (20-35 mg/d) applied in two to three daily doses in adults. In children, hydrocortisone (similar to 8 mg/m\(^2\)/d) is recommended. Patients should be educated about stress dosing and equipped with a steroid card and glucocorticoid preparation for parenteral emergency administration. Follow-up should aim at monitoring appropriate dosing of corticosteroids and associated autoimmune diseases, particularly autoimmune thyroid disease.
Patients in the early stage of hypertensive heart disease tend to have normal echocardiographic findings. The aim of this study was to investigate whether pathology-specific echocardiographic morphologic and functional parameters can help to detect subclinical hypertensive heart disease. One hundred ten consecutive patients without a history and medication for arterial hypertension (AH) or other cardiac diseases were enrolled. Standard echocardiography and two-dimensional speckle tracking -imaging analysis were performed. Resting blood pressure (BP) measurement, cycle ergometer test (CET), and 24-hour ambulatory BP monitoring (ABPM) were conducted. Patients were referred to "septal bulge (SB)" group (basal-septal wall thickness >= 2 mm thicker than mid-septal wall thickness) or "no-SB" group. Echocardiographic SB was found in 48 (43.6%) of 110 patients. In this SB group, 38 (79.2%) patients showed AH either by CET or ABPM. In contrast, in the no-SB group (n = 62), 59 (95.2%) patients had no positive test for AH by CET or ABPM. When AH was solely defined by resting BP, SB was a reasonable predictive sign for AH (sensitivity 73%, specificity 76%). However, when AH was confirmed by CET or ABPM the echocardiographic SB strongly predicted clinical AH (sensitivity 93%, specificity 86%). In addition, regional myocardial deformation of the basal-septum in SB group was significantly lower than in no-SB group (14 +/- 4% vs. 17 +/- 4%; P < .001). In conclusion, SB is a morphologic echocardiographic sign for early hypertensive heart disease. Sophisticated BP evaluation including resting BP, ABPM, and CET should be performed in all patients with an accidental finding of a SB in echocardiography.
Patients with genetic cardiomyopathy that involves myocardial hypertrophy often develop clinically relevant arrhythmias that increase the risk of sudden death. Consequently, guidelines for medical device therapy were established for hypertrophic cardiomyopathy, but not for conditions with only anecdotal evidence of arrhythmias, like Fabry cardiomyopathy. Patients with Fabry cardiomyopathy progressively develop myocardial fibrosis, and sudden cardiac death occurs regularly. Because 24-hour Holier electrocardiograms (ECGs) might not detect clinically important arrhythmias, we tested an implanted loop recorder for continuous heart rhythm surveillance and determined its impact on therapy. This prospective study included 16 patients (12 men) with advanced Fabry cardiomyopathy, relevant hypertrophy, and replacement fibrosis in "loco typico." No patients previously exhibited clinically relevant arrhythmias on Holier ECGs. Patients received an implantable loop recorder and were prospectively followed with telemedicine for a median of 1.2 years (range 0.3 to 2.0 years). The primary end point was a clinically meaningful event, which required a therapy change, captured with the loop recorder. Patients submitted data regularly (14 +/- 11 times per month). During follow-up, 21 events were detected (including 4 asystole, i.e., ECG pauses >= 3 seconds) and 7 bradycardia events; 5 episodes of intermittent atrial fibrillation (>3 minutes) and 5 episodes of ventricular tachycardia (3 sustained and 2 nonsustained). Subsequently, as defined in the primary end point, 15 events leaded to a change of therapy. These patients required therapy with a pacemaker or cardioverter defibrillator implantation and/or anticoagulation therapy for atrial fibrillation. In conclusion, clinically relevant arrhythmias that require further device and/or medical therapy are often missed with Holier ECGs in patients with advanced stage Fabry cardiomyopathy, but they can be detected by telemonitoring with an implantable loop recorder.
Reproducibility and comparison of oxygen-enhanced T\(_1\) quantification in COPD and asthma patients
(2017)
T\(_1\) maps have been shown to yield useful diagnostic information on lung function in patients with chronic obstructive pulmonary disease (COPD) and asthma, both for native T\(_1\) and ΔT\(_1\), the relative reduction while breathing pure oxygen. As parameter quantification is particularly interesting for longitudinal studies, the purpose of this work was both to examine the reproducibility of lung T\(_1\) mapping and to compare T\(_1\) found in COPD and asthma patients using IRSnapShotFLASH embedded in a full MRI protocol. 12 asthma and 12 COPD patients (site 1) and further 15 COPD patients (site 2) were examined on two consecutive days. In each patient, T\(_1\) maps were acquired in 8 single breath-hold slices, breathing first room air, then pure oxygen. Maps were partitioned into 12 regions each to calculate average values. In asthma patients, the average T\(_{1,RA}\) = 1206ms (room air) was reduced to T\(_{1,O2}\) = 1141ms under oxygen conditions (ΔT\(_1\) = 5.3%, p < 5⋅10\(^{−4})\), while in COPD patients both native T\(_{1,RA}\) = 1125ms was significantly shorter (p < 10\(^{−3})\) and the relative reduction to T\(_{1,O2}\) = 1081ms on average ΔT\(_1\) = 4.2%(p < 10\(^{−5}\)). On the second day, with T\(_{1,RA}\) = 1186ms in asthma and T\(_{1,RA}\) = 1097ms in COPD, observed values were slightly shorter on average in all patient groups. ΔT\(_1\) reduction was the least repeatable parameter and varied from day to day by up to 23% in individual asthma and 30% in COPD patients. While for both patient groups T\(_1\) was below the values reported for healthy subjects, the T\(_1\) and ΔT\(_1\) found in asthmatics lies between that of the COPD group and reported values for healthy subjects, suggesting a higher blood volume fraction and better ventilation. However, it could be demonstrated that lung T\(_1\) quantification is subject to notable inter-examination variability, which here can be attributed both to remaining contrast agent from the previous day and the increased dependency of lung T\(_1\) on perfusion and thus current lung state.
Increased aortic stiffness is known to be associated with atherosclerosis and has a predictive value for cardiovascular events. This study aims to investigate the local distribution of early arterial stiffening due to initial atherosclerotic lesions. Therefore, global and local pulse wave velocity (PWV) were measured in ApoE\(^{-/-}\) and wild type (WT) mice using ultrahigh field MRI. For quantification of global aortic stiffness, a new multi-point transit-time (TT) method was implemented and validated to determine the global PWV in the murine aorta. Local aortic stiffness was measured by assessing the local PWV in the upper abdominal aorta, using the flow/area (QA) method. Significant differences between age matched ApoE\(^{-/-}\) and WT mice were determined for global and local PWV measurements (global PWV: ApoE\(^{-/-}\): 2.7 ±0.2m/s vs WT: 2.1±0.2m/s, P<0.03; local PWV: ApoE\(^{-/-}\): 2.9±0.2m/s vs WT: 2.2±0.2m/s, P<0.03). Within the WT mouse group, the global PWV correlated well with the local PWV in the upper abdominal aorta (R\(^2\) = 0.75, P<0.01), implying a widely uniform arterial elasticity.
In ApoE\(^{-/-}\) animals, however, no significant correlation between individual local and global PWV was present (R\(^2\) = 0.07, P = 0.53), implying a heterogeneous distribution of vascular stiffening in early atherosclerosis. The assessment of global PWV using the new multi-point TT measurement technique was validated against a pressure wire measurement in a vessel
phantom and showed excellent agreement. The experimental results demonstrate that vascular stiffening caused by early atherosclerosis is unequally distributed over the length of large vessels. This finding implies that assessing heterogeneity of arterial stiffness by multiple local measurements of PWV might be more sensitive than global PWV to identify early atherosclerotic lesions.
Background. Fast progression of the transaortic mean gradient (P-mean) is relevant for clinical decision making of valve replacement in patients with moderate and severe aortic stenosis (AS) patients. However, there is currently little knowledge regarding the determinants affecting progression of transvalvular gradient in AS patients. Methods. This monocentric retrospective study included consecutive patients presenting with at least two transthoracic echocardiography examinations covering a time interval of one year or more between April 2006 and February 2016 and diagnosed as moderate or severe aortic stenosis at the final echocardiographic examination. Laboratory parameters, medication, and prevalence of eight known cardiac comorbidities and risk factors (hypertension, diabetes, coronary heart disease, peripheral artery occlusive disease, cerebrovascular disease, renal dysfunction, body mass index >= 30 Kg/m(2), and history of smoking) were analyzed. Patients were divided into slow (P-mean < 5 mmHg/year) or fast (P-mean >= 5 mmHg/year) progression groups. Results. A total of 402 patients (mean age 78 +/- 9.4 years, 58% males) were included in the study. Mean follow-up duration was 3.4 +/- 1.9 years. The average number of cardiac comorbidities and risk factors was 3.1 +/- 1.6. Average number of cardiac comorbidities and risk factors was higher in patients in slow progression group than in fast progression group (3.3 +/- 1.5 vs 2.9 +/- 1.7; P = 0.036). Patients in slow progression group had more often coronary heart disease (49.2% vs 33.6%; P = 0.003) compared to patients in fast progression group. LDL-cholesterol values were lower in the slow progression group (100 +/- 32.6 mg/dl vs 110.8 +/- 36.6 mg/dl; P = 0.005). Conclusion. These findings suggest that disease progression of aortic valve stenosis is faster in patients with fewer cardiac comorbidities and risk factors, especially if they do not have coronary heart disease. Further prospective studies are warranted to investigate the outcome of patients with slow versus fast progression of transvalvular gradient with regards to comorbidities and risk factors.
Background
Percutaneous mitral valve repair (PMVR) is increasingly performed in patients with severe mitral regurgitation (MR). Post-procedural MR grading is challenging and an unsettled issue. We hypothesised that the direct planimetry of vena contracta area (VCA) by 3D–transoesophageal echocardiography allows quantifying post-procedural MR and implies further prognostic relevance missed by the usual ordinal scale (grade I-IV).
Methods
Based on a single-centre PMVR registry containing 102 patients, the association of VCA reduction and patients’ functional capacity measured as six-minute walk distance (6 MW) was evaluated. 3D–colour-Doppler datasets were available before, during and 4 weeks after PMVR.
Results
Twenty nine patients (age 77.0 ± 5.8 years) with advanced heart failure (75.9% NYHA III/IV) and severe degenerative (34%) or functional (66%) MR were eligible. VCA was reduced in all patients by PMVR (0.99 ± 0.46 cm\(^2\) vs. 0.22 ± 0.15 cm\(^2\), p < 0.0001). It remained stable after median time of 33 days (p = 0.999). 6 MW improved after the procedure (257.5 ± 82.5 m vs. 295.7 ± 96.3 m, p < 0.01). Patients with a decrease in VCA less than the median VCA reduction showed a more distinct improvement in 6 MW than patients with better technical result (p < 0.05). This paradoxical finding was driven by inferior results in very large functional MR.
Conclusions
VCA improves the evaluation of small residual MR. Its post-procedural values remain stable during a short-term follow-up and imply prognostic information for the patients’ physical improvement. VCA might contribute to a more substantiated estimation of treatment success in the heterogeneous functional MR group.
Aims
The aim of this study was to determine whether the Joint European Societies guidelines on secondary cardiovascular prevention are followed in everyday practice.
Design
A cross-sectional ESC-EORP survey (EUROASPIRE V) at 131 centres in 81 regions in 27 countries.
Methods
Patients (<80 years old) with verified coronary artery events or interventions were interviewed and examined ≥6 months later.
Results
A total of 8261 patients (females 26%) were interviewed. Nineteen per cent smoked and 55% of them were persistent smokers, 38% were obese (body mass index ≥30 kg/m2), 59% were centrally obese (waist circumference: men ≥102 cm; women ≥88 cm) while 66% were physically active <30 min 5 times/week. Forty-two per cent had a blood pressure ≥140/90 mmHg (≥140/85 if diabetic), 71% had low-density lipoprotein cholesterol ≥1.8 mmol/L (≥70 mg/dL) and 29% reported having diabetes. Cardioprotective medication was: anti-platelets 93%, beta-blockers 81%, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers 75% and statins 80%.
Conclusion
A large majority of coronary patients have unhealthy lifestyles in terms of smoking, diet and sedentary behaviour, which adversely impacts major cardiovascular risk factors. A majority did not achieve their blood pressure, low-density lipoprotein cholesterol and glucose targets. Cardiovascular prevention requires modern preventive cardiology programmes delivered by interdisciplinary teams of healthcare professionals addressing all aspects of lifestyle and risk factor management, in order to reduce the risk of recurrent cardiovascular events.
Introduction
Multidisciplinary, complex rehabilitation interventions are an important part of the treatment of chronic diseases. However, little is known about the effectiveness of routine rehabilitation interventions within the German healthcare system. Due to the nature of the social insurance system in Germany, randomised controlled trials examining the effects of rehabilitation interventions are challenging to implement and scarcely accessible. Consequently, alternative pre-post designs can be employed to assess pre-post effects of medical rehabilitation programmes. We present a protocol of systematic review and meta-analysis methods to assess the pre-post effects of rehabilitation interventions in Germany.
Methods and analysis
The respective study will be conducted within the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A systematic literature review will be conducted to identify studies reporting the pre-post effects (start of intervention vs end of intervention or later) in German healthcare. Studies investigating the following disease groups will be included: orthopaedics, rheumatology, oncology, pulmonology, cardiology, endocrinology, gastroenterology and psychosomatics. The primary outcomes of interest are physical/mental quality of life, physical functioning and social participation for all disease groups as well as pain (orthopaedic and rheumatologic patients only), blood pressure (cardiac patients only), asthma control (patients with asthma only), dyspnoea (patients with chronic obstructive pulmonary disease only) and depression/anxiety (psychosomatic patients only). We will invite the principal investigators of the identified studies to provide additional individual patient data. We aim to perform the meta-analyses using individual patient data as well as aggregate data. We will examine the effects of both study-level and patient-level moderators by using a meta-regression method.
Ethics and dissemination
Only studies that have received institutional approval from an ethics committee and present anonymised individual patient data will be included in the meta-analysis. The results will be presented in a peer-reviewed publication and at research conferences. A declaration of no objection by the ethics committee of the University of Würzburg is available (number 20180411 01).
Das Thema dieser Dissertation lautet „SymptomCheck - ein Programm zur Symptom-orientierten Ableitung eines Diagnosevorschlags“. Der Rahmen dieser Dissertation umfasst die ausführliche, eigenständige Konzeption von SymptomCheck, dessen Untersuchung auf Benutzerfreundlichkeit und eine Überprüfung auf allgemeine Validität bezüglich der Verdachtsgenerierung. Hierbei wurde die Entwicklung der Wissensbasis mit dem dafür eigens konzipierten Bewertungsschema entwickelt. Desweiteren wurde eine alltagstaugliche Benutzeroberfläche generiert, die ein breites Personenspektrum adressiert. In einer Pilotstudie I wurde das Programm auf die oben erwähnten Aspekte hin untersucht und dessen Mängel überarbeitet. Die endgültige Version von SymptomCheck wurde sodann sowohl in einer Online-Evaluation wie auch einer weiteren klinischen Anwendung getestet (Pilotstudie II). Während bei der Online-Evaluation der Fokus auf der Untersuchung der Benutzungsqualität lag, wurde in der Pilotstudie II mit stationären Patienten vor allem die Präzision der Verdachtsgenerierung untersucht.
Die vorliegende Arbeit ist demnach vermutlich die erste, die ein selbstentwickeltes Online-Programm im Rahmen einer Online-Evaluation an Probanden und im Rahmen einer klinischen Studie an echten Patienten testete. SymptomCheck ist somit der erste vielversprechende Schritt, ein für den Alltagsgebrauch entwickeltes, breit gefächertes Selbstdiagnoseprogramm klinisch zu validieren.
Here, we present a small Iranian family, where the index patient received a diagnosis of restrictive cardiomyopathy (RCM) in combination with atrioventricular (AV) block. Genetic analysis revealed a novel homozygous missense mutation in the DES gene (c.364T > C; p.Y122H), which is absent in human population databases. The mutation is localized in the highly conserved coil-1 desmin subdomain. In silico, prediction tools indicate a deleterious effect of the desmin (DES) mutation p.Y122H. Consequently, we generated an expression plasmid encoding the mutant and wildtype desmin formed, and analyzed the filament formation in vitro in cardiomyocytes derived from induced pluripotent stem cells and HT-1080 cells. Confocal microscopy revealed a severe filament assembly defect of mutant desmin supporting the pathogenicity of the DES mutation, p.Y122H, whereas the wildtype desmin formed regular intermediate filaments. According to the guidelines of the American College of Medical Genetics and Genomics, we classified this mutation, therefore, as a novel pathogenic mutation. Our report could point to a recessive inheritance of the DES mutation, p.Y122H, which is important for the genetic counseling of similar families with restrictive cardiomyopathy caused by DES mutations.
Background.
Effective antihypertensive treatment depends on patient compliance regarding prescribed medications. We assessed the impact of beliefs related towards antihypertensive medication on blood pressure control in a population-based sample treated for hypertension.
Methods.
We used data from the Characteristics and Course of Heart Failure Stages A-B and Determinants of Progression (STAAB) study investigating 5000 inhabitants aged 30 to 79 years from the general population of Würzburg, Germany. The Beliefs about Medicines Questionnaire German Version (BMQ-D) was provided in a subsample without established cardiovascular diseases (CVD) treated for hypertension. We evaluated the association between inadequately controlled hypertension (systolic RR >140/90 mmHg; >140/85 mmHg in diabetics) and reported concerns about and necessity of antihypertensive medication.
Results.
Data from 293 participants (49.5% women, median age 64 years [quartiles 56.0; 69.0]) entered the analysis. Despite medication, half of the participants (49.8%) were above the recommended blood pressure target. Stratified for sex, inadequately controlled hypertension was less frequent in women reporting higher levels of concerns (OR 0.36; 95%CI 0.17-0.74), whereas no such association was apparent in men. We found no association for specific-necessity in any model.
Conclusion.
Beliefs regarding the necessity of prescribed medication did not affect hypertension control. An inverse association between concerns about medication and inappropriately controlled hypertension was found for women only. Our findings highlight that medication-related beliefs constitute a serious barrier of successful implementation of treatment guidelines and underline the role of educational interventions taking into account sex-related differences.
Kationenkanäle der Canonical Transient Receptor (TRPC)-Familie spielen eine wichtige Rolle in der pathologischen Herzhypertrophie. Neben anderen Isoformen besitzt TRPC4 die Potenz, den strukturellen und funktionellen Umbau des Herzens im Rahmen der pathologischen Hypertrophie über Ca2+-Transienten zu bestärken. TRPC4-Kanäle sind nicht-selektive Kationenkanäle, die für Na+ und Ca2+ durchlässig sind. Sie setzen sich in der Plasmamembran zu Homo- oder Heterotetrameren zusammen. Die TRPC4-Kanalaktivität wird durch die Stimulation von Gq-Protein-gekoppelten Rezeptoren (GPCR) reguliert und führt zu einem Ca2+-Einstrom, der für die Aktivierung von Calcineurin und des nuclear factor of activated T-cells (NFAT) notwendig ist. Eine weitere Aktivierungsform lässt sich über die Entleerung von intrazellulären Ca2+-Speichern (SOCE) aus dem Sarkoplasmatischen Retikulum (SR) nachweisen. Die funktionelle Wirkung des TRPC4 ist von der Expression der beiden Splice-Varianten TRPC4α und TRPC4β abhängig.
Um diese funktionelle Abhängigkeit der Splice-Variante C4β genauer zu charakterisieren, wurden in der vorliegenden Studie zytosolische Ca2+-Signale und deren Aktivierungsmechanismen analysiert. Für die Untersuchungen wurden neonatale Rattenkardiomyozyten (NRC) verwendet, die mit adenoviralen Vektoren infiziert wurden und TRPC4beta (Ad-TRPC4β), TRPC4alpha (Ad-TRPC4α) und beta-Galaktosidase (Ad-ßgal) als Kontrolle exprimierten. Es erfolgte eine Auswertung der Ca2+-Transienten, in der gezeigt werden konnte, dass TRPC4β den Ca2+-Einstrom in schlagenden Kardiomyozyten beeinflusst. Dies machte sich in einer erhöhten Ca2+-Amplitude unter basalen Bedingungen bemerkbar. Ebenfalls konnte deutlich gemacht werden, dass eine Ca2+-Entleerung des SR TRPC4β als sogenannten SOC (speicher-regulierten Kanal, store-operated channel) aktiviert. Außerdem reagierten TRPC4β-infizierte NRCs mit einem gesteigerten Ca2+-Maximalspitzenwert (peak) unter Stimulation mit dem GPCR-Agonisten Angiotensin II. Die Amplitude der Ca2+-Transienten bei Überexpression von Ad-TRPC4β war im Vergleich zur Ad-ßgal-Kontrollgruppe deutlich gesteigert. Darüber hinaus war der Abfall der Ca2+-Transienten der TRPC4β-exprimierenden Zellen beschleunigt. Dies lässt einen kompensatorischen Mechanismus vermuten, mit dem Ziel, einer Ca2+-Überladung der Zelle durch den TRPC4β-induzierten Ca2+-Einstrom entgegenzuwirken. In zusätzlichen Experimenten zeigte sich TRPC4β ebenfalls deutlich sensitiver gegenüber der Angiotensin II-Stimulation als TRPC4α. Weiterführende Untersuchungen ließen erkennen, dass TRPC4β, im Gegensatz zu anderen TRPC-Isoformen, keinen pro-hypertrophen, sondern vielmehr einen pro-apoptotischen Einfluss auf Kardiomyozyten ausübt.
Zusammenfassend zeigt die vorliegende Studie, dass eine erhöhte Aktivität der Splice-Variante TRPC4β mit kritischen Veränderungen zytosolischer Ca2+-Signale verbunden ist und somit ein entscheidender Faktor für die Entstehung und Progression kardialer Pathologien sein könnte.
In der vorliegenden Arbeit wurden 16 Parameter analysiert, die im Rahmen der Herzinsuffizienzdiagnostik eine wichtige Rolle spielen. Alle Bioproben waren an den KNHI-Standorten Würzburg und Göttingen gewonnen worden. Ein Teil der so gewonnenen Biomaterialien wurde lokal analysiert und bei -80°C eingelagert (Erstmessung oder Basismessung), ein Teil wurde nach Berlin versandt und dort unter standardisierten Bedingungen in der KNHI-Biobank bei -80°C eingelagert. Nach 6-8 Jahren wurden gezielt Samples aus der KNHI-Biobank angefordert, nach Würzburg versandt, aufgetaut, und zum zweiten Mal gemessen (Nachmessung).
Die Messergebnisse aus Pärchen von Serum- und EDTA-Proben aus den lokalen und zentral gelagerten Bioproben wurden verglichen (insgesamt somit 4 Gruppen) und statistisch analysiert (Korrelation, Bestimmtheitsmaß R², Streudiagramme, Bland-Altman-Analysen, Regression, 95%-Übereinstimmungsintervalle, Confounderanalyse). Je nach Parameter wurden zwischen 103 und 322 Probenpaare in die Analyse eingeschlossen.
Es konnte gezeigt werden, dass die Lagerung von Biomaterial bei -80°C sinnvoll ist, um in der Zukunft eine genügende Zahl an Patientenwerten für Studien und Analysen bezüglich des Krankheitsbilds Herzinsuffizienz zur Verfügung zu haben. Die Qualität gerade der prognostisch wichtigen Marker hsCRP und NT-proBNP ist als sehr gut zu bewerten, was es dem KNHI ermöglichen dürfte, fast alle eingelagerten Proben zu nutzen. Es wurden verschiedene Akzeptanzbereiche definiert, die sich bei allen Parametern mit Ausnahme von Natrium und Kalium aus den 95%-Übereinstimmungsintervallen der durchgeführten Bland-Altman-Analysen bilden.
Kationenkanäle der Canonical Transient Receptor (TRPC)-Familie spielen eine wichtige Rolle in der pathologischen Herzhypertrophie. Neben anderen Isoformen besitzt TRPC4 die Potenz, den strukturellen und funktionellen Umbau des Herzens im Rahmen der pathologischen Hypertrophie über Ca2+-Transienten zu bestärken. TRPC4-Kanäle sind nicht-selektive Kationenkanäle, die für Na+ und Ca2+ durchlässig sind. Sie setzen sich in der Plasmamembran zu Homo- oder Heterotetrameren zusammen. Die TRPC4-Kanalaktivität wird durch die Stimulation von Gq-Protein-gekoppelten Rezeptoren (GPCR) reguliert und führt zu einem Ca2+-Einstrom, der für die Aktivierung von Calcineurin und des nuclear factor of activated T-cells (NFAT) notwendig ist. Eine weitere Aktivierungsform lässt sich über die Entleerung von intrazellulären Ca2+-Speichern (SOCE) aus dem Sarkoplasmatischen Retikulum (SR) nachweisen. Die funktionelle Wirkung des TRPC4 ist von der Expression der beiden Splice-Varianten TRPC4α und TRPC4β abhängig.
Um diese funktionelle Abhängigkeit der Splice-Variante C4β genauer zu charakterisieren, wurden in der vorliegenden Studie zytosolische Ca2+-Signale und deren Aktivierungsmechanismen analysiert. Für die Untersuchungen wurden neonatale Rattenkardiomyozyten (NRC) verwendet, die mit adenoviralen Vektoren infiziert wurden und TRPC4beta (Ad-TRPC4β), TRPC4alpha (Ad-TRPC4α) und beta-Galaktosidase (Ad-ßgal) als Kontrolle exprimierten. Es erfolgte eine Auswertung der Ca2+-Transienten, in der gezeigt werden konnte, dass TRPC4β den Ca2+-Einstrom in schlagenden Kardiomyozyten beeinflusst. Dies machte sich in einer erhöhten Ca2+-Amplitude unter basalen Bedingungen bemerkbar. Ebenfalls konnte deutlich gemacht werden, dass eine Ca2+-Entleerung des SR TRPC4β als sogenannten SOC (speicher-regulierten Kanal, store-operated channel) aktiviert. Außerdem reagierten TRPC4β-infizierte NRCs mit einem gesteigerten Ca2+-Maximalspitzenwert (peak) unter Stimulation mit dem GPCR-Agonisten Angiotensin II. Die Amplitude der Ca2+-Transienten bei Überexpression von Ad-TRPC4β war im Vergleich zur Ad-ßgal-Kontrollgruppe deutlich gesteigert. Darüber hinaus war der Abfall der Ca2+-Transienten der TRPC4β-exprimierenden Zellen beschleunigt. Dies lässt einen kompensatorischen Mechanismus vermuten, mit dem Ziel, einer Ca2+-Überladung der Zelle durch den TRPC4β-induzierten Ca2+-Einstrom entgegenzuwirken. In zusätzlichen Experimenten zeigte sich TRPC4β ebenfalls deutlich sensitiver gegenüber der Angiotensin II-Stimulation als TRPC4α. Weiterführende Untersuchungen ließen erkennen, dass TRPC4β, im Gegensatz zu anderen TRPC-Isoformen, keinen pro-hypertrophen, sondern vielmehr einen pro-apoptotischen Einfluss auf Kardiomyozyten ausübt.
Zusammenfassend zeigt die vorliegende Studie, dass eine erhöhte Aktivität der Splice-Variante TRPC4β mit kritischen Veränderungen zytosolischer Ca2+-Signale verbunden ist und somit ein entscheidender Faktor für die Entstehung und Progression kardialer Pathologien sein könnte.
Spin echo based cardiac diffusion imaging at 7T: An ex vivo study of the porcine heart at 7T and 3T
(2019)
Purpose of this work was to assess feasibility of cardiac diffusion tensor imaging (cDTI) at 7 T in a set of healthy, unfixed, porcine hearts using various parallel imaging acceleration factors and to compare SNR and derived cDTI metrics to a reference measured at 3 T. Magnetic resonance imaging was performed on 7T and 3T whole body systems using a spin echo diffusion encoding sequence with echo planar imaging readout. Five reference (b = 0 s/mm\(^2\)) images and 30 diffusion directions (b = 700 s/mm\(^2\)) were acquired at both 7 T and 3 T using a GRAPPA acceleration factor R = 1. Scans at 7 T were repeated using R = 2, R = 3, and R = 4. SNR evaluation was based on 30 reference (b = 0 s/mm\(^2\)) images of 30 slices of the left ventricle and cardiac DTI metrics were compared within AHA segmentation. The number of hearts scanned at 7 T and 3 T was n = 11. No statistically significant differences were found for evaluated helix angle, secondary eigenvector angle, fractional anisotropy and apparent diffusion coefficient at the different field strengths, given sufficiently high SNR and geometrically undistorted images. R≥3 was needed to reduce susceptibility induced geometric distortions to an acceptable amount. On average SNR in myocardium of the left ventricle was increased from 29±3 to 44±6 in the reference image (b = 0 s/mm\(^2\)) when switching from 3 T to 7 T. Our study demonstrates that high resolution, ex vivo cDTI is feasible at 7 T using commercial hardware.
Background
T1 mapping sequences such as MOLLI, ShMOLLI and SASHA make use of different technical approaches, bearing strengths and weaknesses. It is well known that obtained T1 relaxation times differ between the sequence techniques as well as between different hardware. Yet, T1 quantification is a promising tool for myocardial tissue characterization, disregarding the absence of established reference values. The purpose of this study was to evaluate the feasibility of native and post-contrast T1 mapping methods as well as ECV maps and its diagnostic benefits in a clinical environment when scanning patients with various cardiac diseases at 3 T.
Methods
Native and post-contrast T1 mapping data acquired on a 3 T full-body scanner using the three pulse sequences 5(3)3 MOLLI, ShMOLLI and SASHA in 19 patients with clinical indication for contrast enhanced MRI were compared. We analyzed global and segmental T1 relaxation times as well as respective extracellular volumes and compared the emerged differences between the used pulse sequences.
Results
T1 times acquired with MOLLI and ShMOLLI exhibited systematic T1 deviation compared to SASHA. Myocardial MOLLI T1 times were 19% lower and ShMOLLI T1 times 25% lower compared to SASHA. Native blood T1 times from MOLLI were 13% lower than SASHA, while post-contrast MOLLI T1-times were only 5% lower. ECV values exhibited comparably biased estimation with MOLLI and ShMOLLI compared to SASHA in good agreement with results reported in literature. Pathology-suspect segments were clearly differentiated from remote myocardium with all three sequences.
Conclusion
Myocardial T1 mapping yields systematically biased pre- and post-contrast T1 times depending on the applied pulse sequence. Additionally calculating ECV attenuates this bias, making MOLLI, ShMOLLI and SASHA better comparable. Therefore, myocardial T1 mapping is a powerful clinical tool for classification of soft tissue abnormalities in spite of the absence of established reference values.
The transcription factor 12 (tcf12) is a basic Helix-Loop-Helix protein (bHLH) of the E-protein family, proven to play an important role in developmental processes like neurogenesis, mesoderm formation, and cranial vault development. In humans, mutations in TCF12 lead to craniosynostosis, a congenital birth disorder characterized by the premature fusion of one or several of the cranial sutures. Current research has been primarily focused on functional studies of TCF12, hence the cellular expression profile of this gene during embryonic development and early stages of ossification remains poorly understood. Here we present the establishment and detailed analysis of two transgenic tcf12:EGFP fluorescent zebrafish (Danio rerio) reporter lines. Using these transgenic lines, we analyzed the general spatiotemporal expression pattern of tcf12 during different developmental stages and put emphasis on skeletal development and cranial suture patterning. We identified robust tcf12 promoter-driven EGFP expression in the central nervous system (CNS), the heart, the pronephros, and the somites of zebrafish embryos. Additionally, expression was observed inside the muscles and bones of the viscerocranium in juvenile and adult fish. During cranial vault development, the transgenic fish show a high amount of tcf12 expressing cells at the growth fronts of the ossifying frontal and parietal bones and inside the emerging cranial sutures. Subsequently, we tested the transcriptional activity of three evolutionary conserved non-coding elements (CNEs) located in the tcf12 locus by transient transgenic assays and compared their in vivo activity to the expression pattern determined in the transgenic tcf12:EGFP lines. We could validate two of them as tcf12 enhancer elements driving specific gene expression in the CNS during embryogenesis. Our newly established transgenic lines enhance the understanding of tcf12 gene regulation and open up the possibilities for further functional investigation of these novel tcf12 enhancer elements in zebrafish.
We aimed to determine a detailed regional ventricular distribution pattern of the novel cardiac nerve PET radiotracer \(^{18}\)F-LMI1195 in healthy rabbits. Ex-vivo high resolution autoradiographic imaging was conducted to identify accurate ventricular distribution of \(^{18}\)F-LMI1195. In healthy rabbits, \(^{18}\)F-LMI1195 was administered followed by the reference perfusion marker \(^{201}\)Tl for a dual-radiotracer analysis. After 20 min of \(^{18}\)F-LMI1195 distribution time, the rabbits were euthanized, the hearts were extracted, frozen, and cut into 20-μm short axis slices. Subsequently, the short axis sections were exposed to a phosphor imaging plate to determine \(^{18}\)F-LMI1195 distribution (exposure for 3 h). After complete \(^{18}\)F decay, sections were re-exposed to determine 201Tl distribution (exposure for 7 days). For quantitative analysis, segmental regions of Interest (ROIs) were divided into four left ventricular (LV) and a right ventricular (RV) segment on mid-ventricular short axis sections. Subendocardial, mid-portion, and subepicardial ROIs were placed on the LV lateral wall. \(^{18}\)F-LMI1195 distribution was almost homogeneous throughout the LV wall without any significant differences in all four LV ROIs (anterior, posterior, septal and lateral wall, 99 ± 2, 94 ± 5, 94 ± 4 and 97 ± 3%LV, respectively, n.s.). Subepicardial \(^{201}\)Tl uptake was significantly lower compared to the subendocardial portion (subendocardial, mid-portion, and subepicardial activity: 90 ± 3, 96 ± 2 and *80 ± 5%LV, respectively, *p < 0.01 vs. mid-portion). This was in contradistinction to the transmural wall profile of \(^{18}\)F-LMI1195 (90 ± 4, 96 ± 5 and 84 ± 4%LV, n.s.). A slight but significant discrepant transmural radiotracer distribution pattern of \(^{201}\)Tl in comparison to \(^{18}\)F-LMI1195 may be a reflection of physiological sympathetic innervation and perfusion in rabbit hearts.
The normal function of the heart relies on a series of complex metabolic processes orchestrating the proper generation and use of energy. In this context, mitochondria serve a crucial role as a platform for energy transduction by supplying ATP to the varying demand of cardiomyocytes, involving an intricate network of pathways regulating the metabolic flux of substrates. The failure of these processes results in structural and functional deficiencies of the cardiac muscle, including inherited cardiomyopathies. These genetic diseases are characterized by cardiac structural and functional anomalies in the absence of abnormal conditions that can explain the observed myocardial abnormality, and are frequently associated with heart failure. Since their original description, major advances have been achieved in the genetic and phenotype knowledge, highlighting the involvement of metabolic abnormalities in their pathogenesis. This review provides a brief overview of the role of mitochondria in the energy metabolism in the heart and focuses on metabolic abnormalities, mitochondrial dysfunction, and storage diseases associated with inherited cardiomyopathies.
Background
Atrial fibrillation (AF) without other stroke risk factors is assumed to have a low annual stroke risk comparable to patients without AF. Therefore, current clinical guidelines do not recommend oral anticoagulation for stroke prevention of AF in patients without stroke risk factors. We analyzed brain magnetic resonance imaging (MRI) imaging to estimate the rate of clinically inapparent (“silent”) ischemic brain lesions in these patients.
Methods
We pooled individual patient-level data from three prospective studies comprising stroke-free patients with symptomatic AF. All study patients underwent brain MRI within 24–48 h before planned left atrial catheter ablation. MRIs were analyzed by a neuroradiologist blinded to clinical data.
Results
In total, 175 patients (median age 60 (IQR 54–67) years, 32% female, median CHA\(_2\)DS\(_2\)-VASc = 1 (IQR 0–2), 33% persistent AF) were included. In AF patients without or with at least one stroke risk factor, at least one silent ischemic brain lesion was observed in 4 (8%) out of 48 and 10 (8%) out of 127 patients, respectively (p > 0.99). Presence of silent ischemic brain lesions was related to age (p = 0.03) but not to AF pattern (p = 0.77). At least one cerebral microbleed was detected in 5 (13%) out of 30 AF patients without stroke risk factors and 25 (25%) out of 108 AF patients with stroke risk factors (p = 0.2). Presence of cerebral microbleeds was related to male sex (p = 0.04) or peripheral artery occlusive disease (p = 0.03).
Conclusion
In patients with symptomatic AF scheduled for ablation, brain MRI detected silent ischemic brain lesions in approximately one in 12 patients, and microbleeds in one in 5 patients. The prevalence of silent ischemic brain lesions did not differ in AF patients with or without further stroke risk factors.
YAP and TAZ, downstream effectors of the Hippo pathway, are important regulators of proliferation. Here, we show that the ability of YAP to activate mitotic gene expression is dependent on the Myb-MuvB (MMB) complex, a master regulator of genes expressed in the G2/M phase of the cell cycle. By carrying out genome-wide expression and binding analyses, we found that YAP promotes binding of the MMB subunit B-MYB to the promoters of mitotic target genes. YAP binds to B-MYB and stimulates B-MYB chromatin association through distal enhancer elements that interact with MMB-regulated promoters through chromatin looping. The cooperation between YAP and B-MYB is critical for YAP-mediated entry into mitosis. Furthermore, the expression of genes coactivated by YAP and B-MYB is associated with poor survival of cancer patients. Our findings provide a molecular mechanism by which YAP and MMB regulate mitotic gene expression and suggest a link between two cancer-relevant signaling pathways.
Aims Acute myocardial infarction (MI) is the major cause of chronic heart failure. The activity of blood coagulation factor XIII (FXIIIa) plays an important role in rodents as a healing factor after MI, whereas its role in healing and remodelling processes in humans remains unclear. We prospectively evaluated the relevance of FXIIIa after acute MI as a potential early prognostic marker for adequate healing.
Methods and results This monocentric prospective cohort study investigated cardiac remodelling in patients with ST-elevation MI and followed them up for 1 year. Serum FXIIIa was serially assessed during the first 9 days after MI and after 2, 6, and 12 months. Cardiac magnetic resonance imaging was performed within 4 days after MI (Scan 1), after 7 to 9 days (Scan 2), and after 12 months (Scan 3). The FXIII valine-to-leucine (V34L) single-nucleotide polymorphism rs5985 was genotyped. One hundred forty-six patients were investigated (mean age 58 ± 11 years, 13% women). Median FXIIIa was 118 % (quartiles, 102–132%) and dropped to a trough on the second day after MI: 109%(98–109%; P < 0.001). FXIIIa recovered slowly over time, reaching the baseline level after 2 to 6 months and surpassed baseline levels only after 12 months: 124 % (110–142%). The development of FXIIIa after MI was independent of the genotype. FXIIIa on Day 2 was strongly and inversely associated with the relative size of MI in Scan 1 (Spearman’s ρ = –0.31; P = 0.01) and Scan 3 (ρ = –0.39; P < 0.01) and positively associated with left ventricular ejection fraction: ρ = 0.32 (P < 0.01) and ρ = 0.24 (P = 0.04), respectively.
Conclusions FXIII activity after MI is highly dynamic, exhibiting a significant decline in the early healing period, with reconstitution 6 months later. Depressed FXIIIa early after MI predicted a greater size of MI and lower left ventricular ejection fraction after 1 year. The clinical relevance of these findings awaits to be tested in a randomized trial.
Although heart failure following myocardial infarction (MI) represents a major health burden, underlying microstructural and functional changes remain incompletely understood. Here, we report on a case of unexpected MI after treatment with the catecholamine isoproterenol in an experimental imaging study in mice using different state-of-the-art imaging modalities. The decline in cardiac function was documented by ultrahigh-frequency echocardiography and speckle-tracking analyses. Myocardial microstructure was studied ex vivo at a spatial resolution of 100 × 100 × 100 μm\(^{3}\) using diffusion tensor magnetic resonance imaging (DT-MRI) and histopathologic analyses. Two weeks after ISO treatment, the animal showed an apical aneurysm accompanied by reduced radial strain in corresponding segments and impaired global systolic function. DT-MRI revealed a loss of contractile fiber tracts together with a disarray of remaining fibers as corresponding microstructural correlates. This preclinical case report provides valuable insights into pathophysiology and morphologic–functional relations of heart failure following MI using emerging imaging technologies.
Background
Telemedicine improves the quality of acute stroke care in rural regions with limited access to specialized stroke care. We report the first 2 years' experience of implementing a comprehensive telemedical stroke network comprising all levels of stroke care in a defined region.
Methods
The TRANSIT-Stroke network covers a mainly rural region in north-western Bavaria (Germany). All hospitals providing acute stroke care in this region participate in TRANSIT-Stroke, including four hospitals with a supra-regional certified stroke unit (SU) care (level III), three of those providing teleconsultation to two hospitals with a regional certified SU (level II) and five hospitals without specialized SU care (level I). For a two-year-period (01/2015 to 12/2016), data of eight of these hospitals were available; 13 evidence-based quality indicators (QIs) related to processes during hospitalisation were evaluated quarterly and compared according to predefined target values between level-I- and level-II/III-hospitals.
Results
Overall, 7881 patients were included (mean age 74.6 years +/- 12.8; 48.4% female). In level-II/III-hospitals adherence of all QIs to predefined targets was high ab initio. In level-I-hospitals, three patterns of QI-development were observed: a) high adherence ab initio (31%), mainly in secondary stroke prevention; b) improvement over time (44%), predominantly related to stroke specific diagnosis and in-hospital organization; c) no clear time trends (25%). Overall, 10 out of 13 QIs reached predefined target values of quality of care at the end of the observation period.
Conclusion
The implementation of the comprehensive TRANSIT-Stroke network resulted in an improvement of quality of care in level-I-hospitals.
Purpose:
Bolus‐based dynamic contrast agent (CA) perfusion measurements of the heart are subject to systematic errors due to CA bolus dispersion in the coronary arteries. To better understand these effects on quantification of myocardial blood flow and myocardial perfusion reserve (MPR), an in‐silico model of the coronary arteries down to the pre‐arteriolar vessels has been developed.
Methods:
In this work, a computational fluid dynamics analysis is performed to investigate these errors on the basis of realistic 3D models of the left and right porcine coronary artery trees, including vessels at the pre‐arteriolar level. Using advanced boundary conditions, simulations of blood flow and CA transport are conducted at rest and under stress. These are evaluated with regard to dispersion (assessed by the width of CA concentration time curves and associated vascular transport functions) and errors of myocardial blood flow and myocardial perfusion reserve quantification.
Results:
Contrast agent dispersion increases with traveled distance as well as vessel diameter, and decreases with higher flow velocities. Overall, the average myocardial blood flow errors are −28% ± 16% and −8.5% ± 3.3% at rest and stress, respectively, and the average myocardial perfusion reserve error is 26% ± 22%. The calculated values are different in the left and right coronary tree.
Conclusion:
Contrast agent dispersion is dependent on a complex interplay of several different factors characterizing the cardiovascular bed, including vessel size and integrated vascular length. Quantification errors evoked by the observed CA dispersion show nonnegligible distortion in dynamic CA bolus‐based perfusion measurements. We expect future improvements of quantitative perfusion measurements to make the systematic errors described here more apparent.
L-type calcium channels (LTCCs) control crucial physiological processes in cardiomyocytes such as the duration and amplitude of action potentials, excitation-contraction coupling and gene expression, by regulating the entry of Ca2+ into the cells. Cardiac LTCCs consist of one pore-forming α1 subunit and the accessory subunits Cavβ, Cavα2δ and Cavγ. Of these auxiliary subunits, Cavβ is the most important regulator of the channel activity; however, it can also have LTCC-independent cellular regulatory functions. Therefore, changes in the expression of Cavβ can lead not only to a dysregulation of LTCC activity, but also to changes in other cellular functions. Cardiac hypertrophy is one of the most relevant risk factors for congestive heart failure and depends on the activation of calcium-dependent prohypertrophic signaling pathways. However, the role of LTCCs and especially Cavβ in this pathology is controversial and needs to be further elucidated.
Of the four Cavβ isoforms, Cavβ2 is the predominant one in cardiomyocytes. Moreover, there are five different splice variants of Cavβ2 (Cavβ2a-e), differing only in the N-terminal region. We reported that Cavβ2b is the predominant variant expressed in the heart. We also revealed that a pool of Cavβ2 is targeted to the nucleus in cardiomyocytes. The expression of the nuclear Cavβ2 decreases during in vitro and in vivo induction of cardiomyocyte hypertrophy and overexpression of a nucleus-targeted Cavβ2 completely abolishes the in vitro induced hypertrophy. Additionally, we demonstrated by shRNA-mediated protein knockdown that downregulation of Cavβ2 enhances the hypertrophy induced by the α1-adrenergic agonist phenylephrine (PE) without involvement of LTCC activity. These results suggest that Cavβ2 can regulate cardiac hypertrophy through LTCC-independent pathways. To further validate the role of the nuclear Cavβ2, we performed quantitative proteome analyses of Cavβ2-deficient neonatal rat cardiomyocytes (NRCs). The results show that downregulation of Cavβ2 influences the expression of various proteins, including a decrease of calpastatin, an inhibitor of the calcium-dependent cysteine protease calpain. Moreover, downregulation of Cavβ2 during cardiomyocyte hypertrophy drastically increases calpain activity as compared to controls after treatment with PE. Finally, the inhibition of calpain by calpeptin abolishes the increase in PE-induced hypertrophy in Cavβ2-deficient cells. These results suggest that nuclear Cavβ2 has Ca2+- and LTCC-independent functions during the development of hypertrophy. Overall, our results indicate a new role for Cavβ2 in antihypertrophic signaling in cardiac hypertrophy.
A novel mono-surface antisymmetric 16-element transmit/receive (Tx/Rx) coil array was designed, simulated, constructed, and tested for cardiac magnetic resonance imaging (cMRI) in pigs at 7T. The cardiac array comprised of a mono-surface 16-loops with two central elements arranged antisymmetrically and flanked by seven elements on either side. The array was configured for parallel transmit (pTx) mode to have an eight channel transmit and 16-channel receive (8Tx/16Rx) coil array. Electromagnetic (EM) simulations, bench-top measurements, phantom, and MRI experiments with two pig cadavers (68 and 46 kg) were performed. Finally, the coil was used in pilot in-vivo measurements with a 60 kg pig. Flip angle (FA), geometry factor (g-factor), signal-to-noise ratio (SNR) maps, and high-resolution cardiac images were acquired with an in-plane resolution of 0.6 mm x 0.6 mm (in-vivo) and 0.3 mm x 0.3 mm (ex-vivo). The mean g-factor over the heart was 1.26 (R = 6). Static phase B-1(+) shimming in a pig body phantom with the optimal phase vectors makes possible to improve the B-1(+) homogeneity by factor > 2 and transmit efficiency by factor > 3 compared to zero phases (before RF shimming). Parallel imaging performed in the in-vivo measurements demonstrated well preserved diagnostic quality of the resulting images at acceleration factors up to R = 6. The described hardware design can be adapted for arrays optimized for animals and humans with a larger number of elements (32-64) while maintaining good decoupling for various MRI applications at UHF (e.g., cardiac, head, and spine).
Einleitung:
TRPC-Kanäle spielen eine wichtige Rolle in der Pathologie der Herzinsuffizienz und kardialen Hypertrophie. Diese Effekte werden unter anderem über den Calcineurin-NFAT-Signalweg vermittelt. Ein wichtiger Interaktionspartner und Regulator von TRPC-Kanälen ist das Protein FKBP52. Mittels eines Yeast Two-Hybrid Systems wurde in einer kardialen cDNA library eine Interaktion zwischen einem C-terminalen Fragment von TRPC3 (AS 742-848), welches außerhalb der bekannten FKBP-Bindungsdomäne (AS 703-714) liegt, und FKBP52 beobachtet. Da dies eine weitere Bindungsstelle in FKBP52 vermuten ließ, erzeugten wir ein Fragment von FKBP52, welches FKBP52s genannt wurde und dem die funktionell relevante PPIase I-Domäne mit der bekannten Bindungsstelle fehlt. Eine erste Co-IP zwischen diesem Fragment und TRPC3 war erfolgreich.
Ziel:
Die Bestimmung, ob die Anwesenheit des verkürzten FKBP52 in vivo die Komplexbildung aus TRPC3 bzw. TRPC4 und dem Wildtyp-FKBP52 unterdrückt. Zusätzlich, ob FKBP52s die Interaktion zwischen TRPC3 bzw. TRPC4 und Calcineurin in vivo unterbricht und damit die Aktivierung des Calcineurin-NFAT-Signalweges hemmt.
Methoden:
Co-Immunopräzipitationen (Co-IP) wurden mit HEK-293-Zellen durchgeführt, die mit cDNA transfiziert wurden, welche Gene für TRPC3, TRPC4, Calcineurin A und FKBP52s enthielt. Zur Bestimmung der nukleären Translokation von NFATc1 mittels Fluoreszenzmikroskopie wurden HEK-293-Zellen mit TRPC3, TRPC4, GFP-NFATc1 ± FKBP52s transfiziert. Die statistische Analyse erfolgte mit einer One-Way ANOVA.
Ergebnisse:
In dieser Arbeit konnte gezeigt werden, dass FKBP52 sowohl mit TRPC3 als auch mit TRPC4 interagiert. Ebenso wurde festgestellt, dass FKBP52 auch ohne seine katalytische PPIase I-Domäne Bindungen mit TRPC3 bzw. TRPC4 eingeht. Dieses FKBP52-Konstrukt nimmt ebenso an der Komplexbildung mit TRPC3 bzw. TRPC4 und Calcineurin teil. Des Weiteren ließ sich für TRPC3 zeigen, dass unter Stimulation mit Carbachol (GPCR-Agonist) bei Anwesenheit dieses gekürzten FKBP52 eine signifikant geringere Aktivierung und Wanderung des Transkriptionsfaktors NFAT in den Nucleus erfolgte.
Schlussfolgerung:
FKBP52 spielt daher eine wichtige Rolle in dieser Signalkaskade, indem es entscheidend an der Aktivierung von Calcineurin und dessen Rekrutierung zum TRPC-Kanalkomplex beteiligt ist und damit auch an der Aktivierung des Calcineurin-NFAT-Signalweges.
Inherited cardiomyopathies are characterized by clinical and genetic heterogeneity that challenge genetic diagnostics. In this study, we examined the diagnostic benefit of exome data compared to targeted gene panel analyses, and we propose new candidate genes. We performed exome sequencing in a cohort of 61 consecutive patients with a diagnosis of cardiomyopathy or primary arrhythmia, and we analyzed the data following a stepwise approach. Overall, in 64% of patients, a variant of interest (VOI) was detected. The detection rate in the main sub-cohort consisting of patients with dilated cardiomyopathy (DCM) was much higher than previously reported (25/36; 69%). The majority of VOIs were found in disease-specific panels, while a further analysis of an extended panel and exome data led to an additional diagnostic yield of 13% and 5%, respectively. Exome data analysis also detected variants in candidate genes whose functional profile suggested a probable pathogenetic role, the strongest candidate being a truncating variant in STK38. In conclusion, although the diagnostic yield of gene panels is acceptable for routine diagnostics, the genetic heterogeneity of cardiomyopathies and the presence of still-unknown causes favor exome sequencing, which enables the detection of interesting phenotype–genotype correlations, as well as the identification of novel candidate genes.
Die nicht-invasive Gefäßdiagnostik stellt einen wichtigen Pfeiler in der Prävention von Herz-Kreislauferkrankungen dar. Während lange Zeit die sonographische Messung der cIMT, als morphologisches Korrelat der Gefäßalterung, als Goldstandard galt, ist in den letzten Jahren in Gestalt der Pulswellenanalyse/PWV-Messung eine Technik weiterentwickelt worden, die, als funktionelles Korrelat der Gefäßalterung, aufgrund der leichteren Durchführbarkeit und geringerer Untersucherabhängigkeit und Kosten vielversprechend ist. So erlaubt die Messung der Pulswelle mittels gewöhnlicher Blutdruckmanschetten, genau wie die cIMT, die Berechnung des individuellen Gefäßalters und die Diagnostik für das Vorliegen eines Endorganschadens der Blutgefäße.
Um die Messergebnisse der beiden Untersuchungen miteinander zu vergleichen, wurden beide in der EUROASPIRE-IV Studie an Patienten mit koronarer Herzkrankheit durchgeführt. Die Auswertung der Messergebnisse der mit dem Vascular Explorer durchgeführten Pulswellenanalyse/PWV-Messung ergab überraschenderweise, dass die Mehrheit der herzkranken Patienten weder eine vaskuläre Voralterung noch einen Endorganschaden der Blutgefäße aufweisen. Im Falle der cIMT-Messung war Gegenteiliges der Fall, was trotz der medikamentösen Therapie der Patienten so zu erwarten war. Weiterhin zeigte sich lediglich eine geringe Korrelation zwischen den Messergebnissen beider Untersuchungen. Die Determinanten der einzelnen Messwerte aus cIMT und Pulswellenanalyse/PWV-Messung waren deckungsgleich mit den in der Literatur beschriebenen Faktoren, wenn auch viele der sonst signifikanten Regressoren das Signifikanzniveau in unserer Auswertung nicht unterschritten.
Eine Limitation der funktionellen Gefäßdiagnostik liegt derzeit darin, dass die Messergebnisse stark von dem verwendeten Messgerät abhängen. Es liegen noch zu wenig Vergleichsstudien vor, um die Messergebnisse, speziell von neueren Geräten wie dem Vascular Explorer, auf andere zu übertragen. Bei der Berechnung des Gefäßalters sollten daher optimalerweise gerätespezifische Normwerte vorliegen, was beim Vascular Explorer nicht der Fall ist. Gleiches gilt für die Verwendung des PWVcf-Grenzwerts für die Diagnose eines Endorganschadens der Blutgefäße.
Analog hat auch die Messung der cIMT gewisse Einschränkungen. So wäre eine weitere Standardisierung der Messorte (A. carotis communis vs Bulbus vs A. carotis interna), zwischen denen sich die durchschnittliche cIMT erheblich unterscheidet, sowie der Messparameter (Minimal- vs Maximal- vs Mittelwert) wünschenswert. Die universelle Anwendung eines cIMT-Grenzwerts zur Diagnose eines Endorganschadens der Blutgefäße ist daher kritisch zu sehen. Dies zeigt sich auch darin, dass in den neuesten Leitlinien der bislang geltende Grenzwert angezweifelt und kein aktuell gültiger Grenzwert mehr genannt wird.
Wir interpretieren unsere Ergebnisse dahingehend, dass unsere Messung der cIMT die zu erwartende pathologische Gefäßalterung bei Patienten mit koronarer Herzkrankheit besser widerspiegelt als die Messung der Pulswelle mit dem Vascular Explorer. Welche der beiden Untersuchungen hinsichtlich der prognostischen Wertigkeit überlegen ist, muss im Rahmen von Längsschnittstudien geklärt werden.
Background
Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT\(^+\)).
Methods
The new U-SPECT5-E with two stationary detectors was used for acquiring data with \(^{99m}\)Tc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT\(^+\) for comparison.
Results
Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT\(^+\). In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT\(^+\)) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR.
Conclusions
While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.
Background: Left ventricular hypertrophy (LVH), defined by the left ventricular mass index (LVMI), is highly prevalent in hemodialysis patients and a strong independent predictor of cardiovascular events. Compared to cardiac magnetic resonance imaging (CMR), echocardiography tends to overestimate the LVMI. Here, we evaluate the diagnostic performance of transthoracic echocardiography (TTE) compared to CMR regarding the assessment of LVMI in hemodialysis patients.
Methods: TTR and CMR data for 95 hemodialysis patients who participated in the MiREnDa trial were analyzed. The LVMI was calculated by two-dimensional (2D) TTE-guided M-mode measurements employing the American Society of Echocardiography (ASE) and Teichholz (Th) formulas, which were compared to the reference method, CMR.
Results: LVH was present in 44% of patients based on LVMI measured by CMR. LVMI measured by echocardiography correlated moderately with CMR, ASE: r = 0.44 (0.34-0.62); Th: r = 0.44 (0.32-0.62). Compared to CMR, both echocardiographic formulas overestimated LVMI (mean increment LVMI (ASE-CMR): 19.5 +/- 19.48 g/m(2),p < 0.001; mean increment LVMI (Th-CMR): 15.9 +/- 15.89 g/m(2),p < 0.001). We found greater LVMI overestimation in patients with LVH using the ASE formula compared to the Th formula. Stratification of patients into CMR LVMI quartiles showed a continuous decrease in increment LVMI with increasing CMR LVMI quartiles for the Th formula (p < 0.001) but not for the ASE formula (p = 0.772). Bland-Altman analysis showed that the Th formula had a constant bias independent of LVMI. Both methods had good discrimination ability for the detection of LVH (ROC-AUC: 0.819 (0.737-0.901) and 0.808 (0.723-0.892) for Th and ASE, respectively).
Conclusions: The ASE and Th formulas overestimate LVMI in hemodialysis patients. However, the overestimation is less with the Th formula, particularly with increasing LVMI. The results suggest that the Th formula should be preferred for measurement of LVMI in chronic hemodialysis patients.
We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available \(^{99m}\)Tc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with \(^{99m}\)Tc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with similar to 100 MBq [\(^{99m}\)TcTc-MIBI or similar to 150 MBq [\(^{99m}\)Tc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1="very poor" to 5="very good". Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.
Metabolic Alterations Caused by Defective Cardiolipin Remodeling in Inherited Cardiomyopathies
(2020)
The heart is the most energy-consuming organ in the human body. In heart failure, the homeostasis of energy supply and demand is endangered by an increase in cardiomyocyte workload, or by an insufficiency in energy-providing processes. Energy metabolism is directly associated with mitochondrial redox homeostasis. The production of toxic reactive oxygen species (ROS) may overwhelm mitochondrial and cellular ROS defense mechanisms in case of heart failure. Mitochondria are essential cell organelles and provide 95% of the required energy in the heart. Metabolic remodeling, changes in mitochondrial structure or function, and alterations in mitochondrial calcium signaling diminish mitochondrial energy provision in many forms of cardiomyopathy. The mitochondrial respiratory chain creates a proton gradient across the inner mitochondrial membrane, which couples respiration with oxidative phosphorylation and the preservation of energy in the chemical bonds of ATP. Akin to other mitochondrial enzymes, the respiratory chain is integrated into the inner mitochondrial membrane. The tight association with the mitochondrial phospholipid cardiolipin (CL) ensures its structural integrity and coordinates enzymatic activity. This review focuses on how changes in mitochondrial CL may be associated with heart failure. Dysfunctional CL has been found in diabetic cardiomyopathy, ischemia reperfusion injury and the aging heart. Barth syndrome (BTHS) is caused by an inherited defect in the biosynthesis of cardiolipin. Moreover, a dysfunctional CL pool causes other types of rare inherited cardiomyopathies, such as Sengers syndrome and Dilated Cardiomyopathy with Ataxia (DCMA). Here we review the impact of cardiolipin deficiency on mitochondrial functions in cellular and animal models. We describe the molecular mechanisms concerning mitochondrial dysfunction as an incitement of cardiomyopathy and discuss potential therapeutic strategies.
In this study we aimed to assess the effects of continuous formalin fixation on diffusion and relaxation metrics of the ex vivo porcine heart at 7 T. Magnetic resonance imaging was performed on eight piglet hearts using a 7 T whole body system. Hearts were measured fresh within 3 hours of cardiac arrest followed by immersion in 10% neutral buffered formalin. T\(_{2}\)* and T\(_{2}\) were assessed using a gradient multi‐echo and multi‐echo spin echo sequence, respectively. A spin echo and a custom stimulated echo sequence were employed to assess diffusion time‐dependent changes in metrics of cardiac diffusion tensor imaging. SNR was determined for b = 0 images. Scans were performed for 5 mm thick apical, midcavity and basal slices (in‐plane resolution: 1 mm) and repeated 7, 15, 50, 100 and 200 days postfixation. Eigenvalues of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) decreased significantly (P < 0.05) following fixation. Relative to fresh hearts, FA values 7 and 200 days postfixation were 90% and 80%, while respective relative ADC values at those fixation stages were 78% and 92%. Statistical helix and sheetlet angle distributions as well as respective mean and median values showed no systematic influence of continuous formalin fixation. Similar to changes in the ADC, values for T\(_{2}\), T\(_{2}\)* and SNR dropped initially postfixation. Respective relative values compared with fresh hearts at day 7 were 64%, 79% and 68%, whereas continuous fixation restored T\(_{2}\), T\(_{2}\)* and SNR leading to relative values of 74%, 100%, and 81% at day 200, respectively. Relaxation parameters and diffusion metrics are significantly altered by continuous formalin fixation. The preservation of microstructure metrics following prolonged fixation is a key finding that may enable future studies of ventricular remodeling in cardiac pathologies.