Comparison of the Prognostic Value of Global and Regional Myocardial Flow Capacity Radius, Myocardial Flow Reserve, and Stress Myocardial Blood Flow Using Rubidium-82 with SiPM PET/CT

Purpose The aim of this study was to assess the most reliable quantitative variable on Rubidium-82 (82Rb) cardiac PET/CT for predicting major adverse cardiovascular events (MACE), on the latest PET camera using silicon photomultipliers digital readout (SiPM) technology. Methods We prospectively enrolled 274 consecutive participants with suspected myocardial ischemia. Participants underwent 82Rb cardiac SiPM PET/CT and were followed-up for MACE over 652 days (interquartile range: 559 to 751 days). For each participant, global and regional myocardial flow reserve (MFR), stress myocardial blood flow (stress MBF) and their combination as myocardial flow capacity radius (MFC radius) were measured. Results On receiver operator curve analysis, MACE prediction was similar for global and regional MFR, stress MBF, and MFC radius (area under the curve; (i) Global: 0.70 vs. 0.71 and 0.73, and (ii) Regional: 0.71 vs. 0.71 and 0.73, respectively, p > 0.1 for all pairwise comparisons). On multivariable analysis, (i) Global: MFR < 1.98, stress MBF < 1.94 mL/g/min, and MFC radius < 3.12, as well as (ii) Regional: MFR < 1.75, stress MBF < 1.75 mL/g/min, and MFC radius < 2.7, emerged all as similar independent predictors of MACE (p < 0.001 for all). Conclusions Using the latest SiPM PET technology with 82Rb, global and regional MFR, stress MBF, and MFC radius are similar powerful predictors of cardiovascular event.