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Microcirculatory Resistance After Primary Percutaneous Coronary Intervention Predicts Residual Myocardial Damage and
Alessandro Candreva1,2, Alexander Gotschy1,3,4, Julia Stehli1
1Department of Cardiology, University Heart Center, University Hospital Zurich University of Zurich Zurich Switzerland.
Background:
Coronary microvascular dysfunction has been associated with adverse cardiovascular events following acute myocardial infarction. This study evaluates the role of the angiography-derived index of microcirculatory resistance (angio-IMR) in predicting myocardial damage in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI).
Methods And Results:
In this post hoc analysis of the CLEVER-ACS (Controlled-Level Everolimus in Acute Coronary Syndromes) trial, the associations between post-PCI angio-IMR of infarct-related coronary arteries (IRAs) and infarct size, microvascular obstruction, and left ventricular ejection fraction at 30 days as assessed by cardiac magnetic resonance were investigated. High post-PCI angio-IMR was defined as ≥40 mm Hg*s . In non-IRAs, angio-IMR was measured before IRA-PCI. A total of 52 IRAs and 94 non-IRAs of 52 patients were analyzed. Post-PCI angio-IMR was 41.5 (interquartile range [IQR], 28.5-55.7) mm Hg*s in IRAs and pre-PCI angio-IMR was 43.7 (IQR, 31.7-54.0) mm Hg*s in non-IRAs (P=0.70). Patients with high post-PCI angio-IMR (52%) exhibited a larger myocardial infarct size (36.0 [IQR, 23.0-52.5] g versus 14.5 [IQR, 6.50-26.5] g, P<0.001) and a lower left ventricular ejection fraction (46.5% [IQR, 39.5%-49.5%] versus 55.0% [IQR, 48.0%-61.4%], P=0.002) at 30 days as compared with those with low post-PCI angio-IMR values. Post-PCI angio-IMR positively correlated with myocardial infarct size (r=0.45, P=0.001) and extent of microvascular obstruction (r=0.40, P=0.004) at 30 days. Post-PCI angio-IMR predicted myocardial infarct size (area under the curve, 0.78 [IQR, 0.65-0.92]; P=0.001) and extent of microvascular obstruction (area under the curve, 0.74 [IQR, 0.60-0.89]; P=0.009) at 30 days.
Conclusions:
In patients with ST-segment-elevation myocardial infarction, post-PCI angio-IMR was identified as independent predictor of myocardial infarct size and extent of microvascular obstruction.
Registration:
URL: https://clinicaltrials.gov; Unique Identifier: NCT01529554.
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