Clinical implication of totally occluded infarct-related coronary artery in non-ST-segment elevation myocardial infarction: the TOTAL-NSTEMI study

A subset ofpatients found to have total occlusion of the culprit artery (TOCA), present with non-ST-segment elevation myocardial infarction (NSTEMI) and elevated biomarkers. The aim of this study is to assess the effect of the TOCA in patients presenting with NSTEMI.This multicenter observational study was retrospectively conducted between 2015 and 2019. Thrombolysis in myocardial infarction (TIMI) flow grades 0-1 was defined as the TOCA. The primary end point included a combination of all-cause death, myocardial infarction, target vessel revascularization, stent thrombosis, and stroke.Of 3272 patients, TIMI 0-1 flow in the culprit artery was present in 488 (14.9%) patients. TOCA was more likely to be of thrombotic origin (54.1% vs. 10.3%; P < 0.001) and visible collaterals (22.5% vs. 4.4%; P < 0.001). The rates of 30-day (14.3% vs. 7.2%; P < 0.001) and 2-year (25% vs. 19.1%; P = 0.003) primary end points were significantly higher in TOCA patients. Fatal arrhythmias were remarkably higher at 30-day (8.6% vs. 4%; P < 0.001) and 2-year (9% vs. 5.2%; P = 0.001) follow-ups. Mechanical complications were also higher in patients with TOCA at 30 days (0.8% vs. 0.2%; P = 0.013). Moreover, TOCA (OR, 1.379; P = 0.001) was one of the independent predictors of MACCE in NSTEMI patients.The current data suggest that patients with TOCA in the context of NSTEMI are at higher risk of MACCE, fatal arrhythmias, and mechanical complications.