A systematic review and meta-analysis published in the European Heart Journal assessed the difference in outcomes between totally occluded and non-occluded culprit arteries in patients with non-ST elevation myocardial infarction (NSTEMI). The findings revealed a higher risk of mortality and major adverse cardiac events in patients with NSTEMI who demonstrate a totally occluded culprit vessel on coronary angiography.

In this analysis, 7 studies with 40,777 patients were included. Of these, 10,415 (25.5%) patients had an occluded culprit artery with a predominant infero-lateral distribution (40% right coronary and 33% left circumflex artery). There was an increased risk of both major cardiac adverse events [short-term relative risk (RR): 1.41; confidence interval (CI): 1.17, 1.70; P = 0.0003; I² = 26%; medium- to long-term RR: 1.32; CI: 1.11, 1.56; P = 0.001; I² = 25%] and all-cause mortality (short-term RR: 1.67; CI: 1.31, 2.13; P < 0.0001; I² = 41%; medium to long-term RR: 1.42; CI: 1.08, 1.86; P = 0.01; I² = 32%) with total occlusion of the culprit artery. The researchers suggested that there is a need for better risk stratification tools for identifying such high-risk acute coronary syndrome patients for facilitating earlier revascularization in order to improve outcomes.