P964Relationships between extent of ischemic burden and changes in absolute myocardial perfusion after chronic total occlusion percutaneous coronary intervention

Abstract Background The patient benefits after chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) are being questioned. Purpose The present study explored the relationships between baseline ischemic burden findings and subsequent changes in absolute myocardial perfusion after CTO PCI. Methods Consecutive patients underwent serial [15O]H2O positron emission tomography perfusion imaging prior and 3 months after successful CTO PCI. Change in perfusion defect size (in myocardial segments), quantitative (hyperemic) myocardial blood flow (MBF) and coronary flow reserve (CFR) in the CTO area were compared between patients with a limited (0–1 segment), moderate (2–3 segments) and large perfusion defect (≥4 segments). Results 193 patients were included, with 15, 61 and 117 patients having a limited, moderate and large perfusion defect at baseline. Hyperemic MBF and CFR were lower in a large perfusion defect compared to smaller defects (all comparisons p