The association between invasive microvascular function and CMR-derived microvascular injury indicators and left ventricular function and infarct size at 1-month after reperfused STEMI

Abstract Background The restoration of the coronary microcirculation in ST-segment elevation myocardial infarction (STEMI) patients remains hampered in up to 50% of the STEMI patients after successful primary percutaneous coronary intervention (PCI). The association between the coronary microvascular function and injury indicators and functional outcome remains debated. Purpose This study aims to investigate the relation between post-PCI invasive microvascular function and cardiovascular magnetic resonance (CMR)-derived microvascular injury indicators and left ventricular (LV) function and infarct size (IS) at 1-month after STEMI. Methods The study was performed in 110 STEMI patients who underwent angiography for primary PCI and at 1-month follow-up. Invasive assessment of coronary microcirculation physiology in the culprit artery was performed during both procedures and included coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). Data were available for 101 patients. A ratio of >2 for CFR and a value of