Clinical Significance of Culprit Vessel Occlusion in Patients With Non–ST-Elevation Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

In patients with non–ST-elevation myocardial infarction (NSTEMI), total occlusion of the culprit coronary artery (OCA) is not uncommon. We sought to determine the frequency and clinical impact of OCA at presentation in a large population of patients presenting with NSTEMI and who underwent systematic early invasive management. We performed a post hoc analysis of the TAO (Treatment of Acute Coronary Syndrome with Otamixaban) randomized trial, which included patients with NSTEMI with systematic coronary angiography within 72 hours. We compared the baseline characteristics and outcomes of patients according to whether the culprit vessel was occluded (thrombolysis in myocardial infarction flow grade [TFG] 0 to 1) or patent (TFG 2 to 3) at presentation. A total of 7,473 patients with NSTEMI with only 1 culprit lesion identified were enrolled, of whom 1,702 patients had OCA (22.8%). In the OCA group, coronary angiography was performed earlier (18 ± 15 vs 20 ± 16 hours, p <0.01), the culprit lesion was less likely to be the left anterior descending artery (26.5% vs 41.4%, p <0.001) but with more frequent angiographic thrombus (49.9% vs 22.7%, p <0.01). Culprit artery percutaneous coronary intervention during the index procedure was also more frequent (88.5% vs 78.1%, p <0.001) but with a lower rate of TFG grade 3 after the procedure and higher subsequent peak troponin I levels (8.3 ± 13.6 µg/L vs 5.6 ± 11.9 µg/L, p <0.001). At day 7, patients with OCA had higher mortality, and this persisted after adjustment on gender, Grace risk score, cardiovascular risk factors, and culprit vessel location (0.9% vs 0.4%, p = 0.02; adjusted odds ratio [OR] = 2.55, 95% confidence interval [CI] 1.23 to 5.29, p = 0.01). The absolute difference of mortality was maintained through 30 days: 1.2% versus 0.8%, p = 0.13; OR: 1.72, 95% CI 0.97 to 3.05, but mortality rates were similar by 180 days: 1.5% versus 1.6%, p = 0.8, adjusted OR = 1.11, 95% CI 0.69 to 1.80, p = 0.66. In conclusion, a significant proportion of patients with NSTEMI have a totally occluded culprit vessel at presentation. These patients are at higher risk of early mortality but not at 6 months.