Background: Non-ST segment elevation myocardial infarction (NSTEMI) patients presenting with occluded culprit artery (OCA) may be at higher risk for worse outcomes. We sought to compare in-hospital (IH) mortality between patients presenting with NSTEMI with and without OCA, and ST-segment elevation myocardial infarction (STEMI).
Methods: This retrospective analysis studied 14,037 patients enrolled in the Portuguese National Registry of Acute Coronary Syndromes. Three groups were defined: (A) STEMI (n = 8616); (B) OCA-NSTEMI (n = 1309); and (C) non-OCA NSTEMI (n = 4112). Baseline characteristics, therapeutic strategies, and outcomes were compared. Multivariate analysis was performed to assess the risk of IH all-cause mortality across the prespecified groups.
Results: Twenty-four percent of NSTEMI patients presented with OCA. The left circumflex artery was more frequently the culprit artery in group B (12.4% A vs 34.5% B vs 26.0% C; P<.001) and this group was also less likely to receive percutaneous revascularization (95.2% A vs 69.7% B vs 83.2% C; P<.001). The incidence of left ventricular systolic dysfunction was higher in group A and lower in group C (19.9% A vs 12.2% B vs 8.1% C; P<.001). The adjusted risk of IH mortality was significantly higher in group A when compared with group B (3.9% A vs 1.8% B; odds ratio, 2.34; 95% confidence interval, 1.34-4.07; P<.01) and in group B when compared with group C (1.8% B vs 0.9% C; odds ratio, 2.25; 95% confidence interval, 1.17-4.35; P=.02).
Conclusion: OCA-NSTEMI patients had worse IH outcomes than non-OCA NSTEMI patients and better IH outcomes than STEMI patients, suggesting the existence of a continuum of increased risk of IH mortality across these groups.
Keywords: myocardial infarction; occluded culprit artery; prognosis.