11C-meta-hydroxyephedrine defects persist despite functional improvement in hibernating myocardium

Abstract

Background-Regional cardiac sympathetic nerve dysfunction develops in hibernating myocardium and may play a role in its association with sudden cardiac death. Interventions to improve cardiac function (i.e., revascularization) improve survival, but the potential reversibility of sympathetic nerve dysfunction remains unclear.

Sympathetic nerve damage and restoration after ischemia-reperfusion injury as assessed by 11C-hydroxyephedrine

“…The regional 11 C-HED uptake defect (arrows) with preserved 18 F-FDG uptake is seen only after ischemia. The defect in 11 C-HED uptake at 1 week is reduced at 2 months 11 C-HED PET [26]. In human hearts, slow (after >18 months) but progressive reinnervation has been shown by various approaches including PET imaging in patients after heart transplantation [27].…”

Creation of clinically relevant model of chronic heart failure: Application of multi-modality imaging to define physiology

“…Additionally, due to the non-invasive technique of these imaging tools, their model and imaging approach can provide a means to evaluate the progression of HF and to quantify the temporal changes in flow and metabolism. In addition to the information provided on perfusion and metabolic outcomes, additional imaging could be applied to interrogate regional activation of critical receptors or enzymes within the myocardium, [24][25][26][27][28] neurohormonal changes, [29][30][31][32][33] along with regional changes in myocardial hypoxia, 34 apoptosis, 35,36 necrosis, 37 and fibrosis. 38 Unfortunately, the current study reported a high attrition (overall survival rate of 26%) with a major cause of death attributable to lethal arrhythmias during the perioperative period.…”

Current and Future Clinical Applications of Cardiac Positron Emission Tomography

“…31 13 NH3 also offers good accuracy for measuring absolute myocardial blood flow (MBF), but is less practical than 82 Rb because it requires a cyclotron. 18 F-flurpiridaz is a novel radiotracer that is currently undergoing evaluation in a Phase 3 trial. Given that it is an 18 F labeled compound, a cyclotron is required for production.…”

“…Given that it is an 18 F labeled compound, a cyclotron is required for production. 18 Fflurpiridaz has a longer half-life of 110 min, which affords the option of centralized production and distribution to individual centers within close proximity. Moreover, 18 F-flurpiridaz is also suitable for exercise stress testing; has superior spatial resolution because of its very short positron range, as well as high first-pass extraction even at increased flow rates, rendering it ideal for flow quantification.…”

“…The rest perfusion 13 NH3 images demonstrate significant reduction in tracer uptake in the septal, inferior walls and apex (red arrows). 18 F-fluorodeoxyglucose (FDG) metabolism imaging shows significant uptake in the septal, inferior walls and apex (white arrows), indicating there is significant perfusionmetabolism mismatch, or hibernating myocardium in these regions (A). The quantified mismatch score is 29% of the left ventricle (LV; red arrow) and match score was 8.6% of the LV (green arrow) (B).…”