The following is the summary of “Clinical Significance of Culprit Vessel Occlusion in Patients With Non–ST-Elevation Myocardial Infarction Who Underwent Percutaneous Coronary Intervention” published in the February 2023 issue of Cardiovascular Disease by Popovic, et al.

Coronary artery (CA) blockage is prevalent in patients with non-ST-elevation myocardial infarction (NSTEMI). Researchers aimed to study a large sample of patients who presented with NSTEMI and were treated systematically early using invasive methods to establish OCA’s prevalence and clinical significance at presentation. After the fact, investigators analyzed data from the TAO (Treatment of Acute Coronary Syndrome with Otamixaban) randomized trial, which comprised patients with NSTEMI who underwent systematic coronary angiography within 72 hours. Whether the culprit artery was occluded (thrombolysis in myocardial infarction flow grade [TFG] 0-1) or patent (TFG 2-3) at presentation, they examined the baseline characteristics and outcomes of patients. 

An overall number of 7,473 patients with NSTEMI were included, with 1,702 patients (22.8%) having OCA. While coronary angiography was performed sooner in the OCA group (18  ±15 vs. 20  ±16 hours, P<0.01), the location of the culprit lesion was more often the left anterior descending artery in the OCA group (26.5% vs. 41.4%, P<0.001) and angiographic thrombus was more common in the OCA group (49.9% vs. 22.5%, P<0.01). In addition, the prevalence of culprit artery percutaneous coronary intervention during the index procedure was higher (88.5% vs. 78.1%, P<0.001), despite a lower rate of TFG grade 3 following the surgery and higher subsequent peak troponin I levels (8.3 ± 13.6  µg/L vs 5.6 ± 11.9  µg/L, P<0.001). 

After controlling for gender, Grace risk score, cardiovascular risk factors, and the location of the offending vessel, patients with OCA still had a higher 7-day mortality rate than those with non-OCA (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). At 30 days, there was still an absolute difference in death (1.2% against 0.8%, P=0.13; OR: 1.72, 95% CI 0.97 to 3.05), however by 180 days, the two groups had equal mortality rates: Comparison of 1.5% and 1.6% yields a p-value of 0.8, with an adjusted odds ratio of 1.11 (95% CI 0.69 to 1.80) and a significance level of (P=0.66). In conclusion, many people who have an NSTEMI present with a fully obstructed culprit vessel. While there is an increased risk of death in these patients, that risk does not exist at 6 months.