Abstract 2947: A Novel [F-18] labeled PET Tracer for the Characterization of Coronary Artery Disease: Preliminary Evaluation in a Coronary Occlusion Rat Model
Background: PET flow tracers such as [N-13]-ammonia, [O-15]-water and [Rb-82] have been used for myocardial perfusion PET imaging, but require onsite tracer production due to their short radioactive half-lives. We examined the feasibility of a new [F-18]-labeled pyridazinone analogue ([F-18]-BMS-747158 – 02) to characterize tracer kinetics in normal, and ischemic and reperfused myocardium.
Methods and results: Myocardial [F-18]-BMS-747158 – 02 distribution in normal rats (n=7) and rats with left coronary occlusion model (n=22) were analyzed with a dedicated small animal PET scanner over a period of 120min (or 60min) after tracer injection. Normal rat myocardium demonstrated intense and homogeneous [F-18]-BMS-747158 – 02 uptake throughout the left ventricle. At 15min, 45min and 115min after tracer injection, heart-to-lung uptake ratios were 14.6 ± 3.1, 12.7 ± 3.5 and 8. ± 72.5 and heart-to-liver uptake ratios were 2.1 ± 0.8, 2.4 ± 0.5 and 2.8 ± 0.4. In the coronary occlusion model rats, [F-18]-BMS-747158 – 02 was injected 1 min after coronary occlusion, and PET images demonstrated uptake defects in all hearts at 15 min post injection. The defect size remained stable in a permanent coronary occlusion model (n=5) (37. ± 68.8, 37.4 ± 10.2 and 36.2 ± 9.8 LV% at 15min, 45min and 115min after tracer injection, respectively). In the reperfused heart (3min LCA occlusion) a time dependent decrease of defect size after reperfusion (16.2 ± 9.3, 6.0 ± 6.5 and 1.4 ± 1.3 LV% at 15min, 45min and 115min post injection, respectively) due to delayed uptale in ischemic area was observed. Tracer re-injection promoted the redistribution at ischemic area of reperfused heart.
Conclusion: [F-18]-BMS-747158 – 02 demonstrated excellent image quality for cardiac imaging over 120min. Coronary occlusion yielded uptake defects in the myocardium, and reperfusion resulted in redistribution of the tracer into the defect area. The new [F-18]-labeled compound demonstrated promising properties as a new class of PET tracer to assess coronary perfusion as well as viability after one tracer application during a stress procedure.