Prevalence, predictors and outcomes of patients with totally occluded culprit artery in non-ST-elevation myocardial infarction.

Abstract

Background: The implications of occluded culprit arteries in non-ST-elevation myocardial infarction (NSTEMI) patients require further study. This study sought to compare their outcomes with other NSTEMI and STEMI patients.

Methods: Data were analysed from patients with NSTEMI and who underwent single-vessel percutaneous coronary intervention (PCI) within the Melbourne Interventional Group between 2005 and 2017. Those with occluded culprit vessels were compared to non-occluded culprit vessels. The primary endpoint was 30-day major adverse coronary events (MACE). Secondary endpoints included 12-month MACE and National Death Index-linked mortality. Secondary analysis compared outcomes between STEMI and NSTEMI patients with occluded arteries.

Results: A total of 6,829 patients with NSTEMI had single-vessel PCI, of which 954 (14%) had occluded culprit arteries. Most occluded culprit arteries were non-left anterior descending (LAD) (right coronary artery (RCA) 39% vs circumflex 33% vs LAD 26%, p < 0.001). Cardiogenic shock and left ventricular dysfunction were higher in the occluded artery group, but non-occlusion patients had higher baseline comorbidities. Thirty-day MACE was higher in the occluded artery group (6.7% vs 3.8%, p < 0.001). Multivariate Cox proportional hazards regression identified occluded arteries as an independent predictor of 30-day MACE (HR = 1.93, 95% CI 1.4–2.6). However, long-term outcomes in the NSTEMI occluded artery group were better than the overall NSTEMI cohort. The STEMI cohort had higher 30-day all-cause mortality (5.2% vs 1.3%, p < 0.001) and MACE (8.7% vs 6.7%, p = 0.046) than the NSTEMI occluded artery group.

Conclusion: Whilst NSTEMI patients with occluded culprit arteries represented a more unstable subgroup early on, long-term outcomes appeared to be more dependent on baseline comorbidities. Despite potential delays in emergent PCI, they represented a lower risk group than STEMI patients.