A simple angio-based coronary flow assessment of culprit vessels in primary percutaneous coronary intervention is associated with long-term prognosis after ST-segment-elevation myocardial infarction

Despite prompt reperfusion, the risk of adverse clinical outcomes following ST-segment-elevation myocardial infarction (STEMI) remains pronounced, owing partly to suboptimal reperfusion. However, coronary functional evaluation is seldom feasible during primary percutaneous coronary intervention (PPCI). We aimed to examine the clinical implication of a simple coronary assessment based on single-angiographic view (μQFR) during PPCI in discriminating impaired coronary flow and adverse outcomes for STEMI. STEMI Patients undergoing successful PPCI were enrolled and followed up prospectively from 4 medical centers in China. Post-PPCI μQFR of culprit vessels were analyzed. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of cardiac death, non-fatal MI, ischemia-driven target-vessel revascularization and readmission for heart failure. A total of 570 patients with STEMI were enrolled, and post-PCI μQFR was analyzable in 557 (97.7%) patients, with a median of 0.94. Patients with low post-PCI μQFR showed higher incidence of adverse outcomes than those with high μQFR, showing a 2.5-fold increase in the risk for MACE (hazard ratio: 2.51, 95% confidence intervals: 1.33 to 4.72; P = 0.004). Moreover, post-PCI μQFR significantly increased discriminant ability for the occurrence of MACE when added to traditional GRACE risk score for STEMI (integrated discrimination improvement: 0.029; net reclassification index: 0.229; P