Impact of chronic total occlusion in a non-infarct-related coronary artery on myocardial injury assessed by cardiac magnetic resonance imaging and prognosis in ST-elevation myocardial infarction

Background: Mechanisms underlying increased mortality in patients with chronic total occlusion (CTO) of a non-infarct- related artery (non-IRA) are unknown. Cardiac magnetic resonance (CMR) is uniquely suited to provide important mechanistic and pathophysiological information on myocardial damage and reperfusion injury. Aim of this study was to investigate the association of a CTO in a non-IRA with myocardial damage assessed by CMR in patients with ST-elevation myocardial infarction (STEMI). Methods: STEMI patients (n = 791) were stratified according to the presence of single-vessel disease (SVD), multivessel disease (MVD) without a CTO and MVD with a concomitant CTO in a non-IRA. CMR parameters of myocardial injury and clinical outcome after 12 months (major adverse cardiac events [MACE]: death, re-infarction, readmission for heart failure) were compared between groups. Results: A CTO in a non-IRA was present in 74 patients (9%), whereas 372 (47%) had MVD without a CTO and 345 (44%) had SVD. Patients with a CTO in a non-IRA had significantly larger infarcts, a lower myocardial salvage index and lower left ventricular ejection fraction as compared to patients with SVD or MVD without a CTO. MACE rates were significantly higher in patients with MVD and concomitant non-IRA CTO (9.7%) versus MVD patients without CTO (6.5%) and SVD patients (4.1%) (p = 0.015). MVD with non-IRA CTO was a significant independent predictor of clinical outcome [hazard ratio 2.06, 95% confidence interval 1.11-3.82, p = 0.021]. Conclusion: In patients with acute reperfused STEMI, the presence of a CTO in a non-IRA was associated with larger myocardial damage and increased MACE rates. (c) 2018 Elsevier B.V. All rights reserved.