Indicators of abnormal PET coronary flow capacity in detecting cardiac ischemia.

Coronary flow capacity (CFC) categorizes severity of left ventricular (LV) ischemia by PET myocardial blood flow (MBF). Our objective was to correlate abnormal CFC with other indicators of regional ischemia. Data were examined retrospectively for 231 patients evaluated for known/suspected CAD who underwent rest and regadenoson-stress Rb PET/CT. MBF and myocardial flow reserve (MFR) were quantified, from which CFC was categorized as Normal CFC (1), Minimally reduced (2), Mildly reduced (3), Moderately reduced (4), and Severely reduced (5) for the three main arterial territories as well as globally. Relative perfusion summed stress score (SSS) and systolic phase contraction bandwidth (BW) were assessed. Accuracy to detect arteries with CFC ≥ 4 was highest for a Regional Index combining SSS and BW (88 ± 3%). A Global Index formed from stress ejection fraction, SSS and BW was the most accurate means of identifying patients with global CFC ≥ 4 (84 ± 3%). Arteries with abnormal CFC derived from absolute myocardial blood flow measurements are accurately identified by composite parameters combining regionally aberrant relative perfusion patterns and asynchrony.