@article{ChenWernerKoshinoetal.2022, author = {Chen, Xinyu and Werner, Rudolf A. and Koshino, Kazuhiro and Nose, Naoko and M{\"u}hlig, Saskia and Rowe, Steven P. and Pomper, Martin G. and Lapa, Constantin and Decker, Michael and Higuchi, Takahiro}, title = {Molecular Imaging-Derived Biomarker of Cardiac Nerve Integrity - Introducing High NET Affinity PET Probe \(^{18}\)F-AF78}, series = {Theranostics}, volume = {12}, journal = {Theranostics}, number = {9}, doi = {10.7150/thno.63205}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300685}, pages = {4446 -- 4458}, year = {2022}, abstract = {Background: Radiolabeled agents that are substrates for the norepinephrine transporter (NET) can be used to quantify cardiac sympathetic nervous conditions and have been demonstrated to identify high-risk congestive heart failure (HF) patients prone to arrhythmic events. We aimed to fully characterize the kinetic profile of the novel \(^{18}\)F-labeled NET probe AF78 for PET imaging of the cardiac sympathetic nervous system (SNS) among various species. Methods: \(^{18}\)F-AF78 was compared to norepinephrine (NE) and established SNS radiotracers by employing in vitro cell assays, followed by an in vivo PET imaging approach with healthy rats, rabbits and nonhuman primates (NHPs). Additionally, chase protocols were performed in NHPs with NET inhibitor desipramine (DMI) and the NE releasing stimulator tyramine (TYR) to investigate retention kinetics in cardiac SNS. Results: Relative to other SNS radiotracers, 18F-AF78 showed higher transport affinity via NET in a cell-based competitive uptake assay (IC\(^{50}\) 0.42 ± 0.14 µM), almost identical to that of NE (IC\(^{50}\), 0.50 ± 0.16 µM, n.s.). In rabbits and NHPs, initial cardiac uptake was significantly reduced by NET inhibition. Furthermore, cardiac tracer retention was not affected by a DMI chase protocol but was markedly reduced by intermittent TYR chase, thereby suggesting that \(^{18}\)F-AF78 is stored and can be released via the synaptic vesicular turnover process. Computational modeling hypothesized the formation of a T-shaped π-π stacking at the binding site, suggesting a rationale for the high affinity of \(^{18}\)F-AF78. Conclusion: \(^{18}\)F-AF78 demonstrated high in vitro NET affinity and advantageous in vivo radiotracer kinetics across various species, indicating that \(^{18}\)F-AF78 is an SNS imaging agent with strong potential to guide specific interventions in cardiovascular medicine.}, language = {en} } @article{HiguchiSerflingRoweetal.2022, author = {Higuchi, Takahiro and Serfling, Sebastian E. and Rowe, Steven P. and Werner, Rudolf A.}, title = {Therapeutic effects of lipid lowering medications on myocardial blood flow, inflammation, and sympathetic nerve activity using nuclear techniques}, series = {Current Cardiology Reports}, volume = {24}, journal = {Current Cardiology Reports}, number = {12}, doi = {10.1007/s11886-022-01792-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324599}, pages = {1849-1853}, year = {2022}, abstract = {Purpose of Review Statins are routinely applied in patients with coronary artery disease, as they allow significantly to reduce blood cholesterol levels. Although those drugs are endorsed by current guidelines and prescribed routinely, a substantial portion of patients are still statin-intolerant and image-piloted strategies may then be helpful to identify patients that need further intensified treatment, e.g., to initiate treatment with proprotein convertase subtilisin / kexin type 9 inhibitors (PCSK9i). In addition, it has also been advocated that statins exhibit nonlipid, cardio-protective effects including improved cardiac nerve integrity, blood flow, and anti-inflammatory effects in congestive heart failure (HF) patients. Recent Findings In subjects after myocardial infarction treated with statins, \(^{123}\)I-metaiodobenzylguanidine (MIBG) scintigraphy has already revealed enhanced cardiac nerve function relative to patients without statins. In addition, all of those aforementioned statin-targeted pathways in HF can be visualized and monitored using dedicated cardiac radiotracers, e.g., \(^{123}\)I-MIBG or \(^{18}\)F-AF78 (for cardiac nerve function), \(^{18}\)F-flurpiridaz (to determine coronary flow) or \(^{68}\)Ga-PentixaFor (to detect inflammation). Summary Statins exhibit various cardio-beneficial effects, including improvement of cardiac nerve function, blood flow, and reduction of inflammation, which can all be imaged using dedicated nuclear cardiac radiotracers. This may allow for in vivo monitoring of statin-induced cardioprotection beyond lipid profiling in HF patients.}, language = {en} }