Comparison of long-term outcomes between older Asian and white patients with non-ST-segment elevation myocardial infarction: Findings from CRUSADE-CMS database

Background In the United States as well as globally, Asians are a growing proportion of patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI), yet little is known about their longitudinal outcomes. Methods We linked Centers for Medicare & Medicaid claims data to detailed clinical data for 37,702 NSTEMI patients ≥65 years old treated at 444 CRUSADE hospitals between 2003 and 2006 to examine longitudinal outcomes. We used Cox proportional hazards modeling to compared outcomes between Asian and white patients, adjusting for differences in baseline patient characteristics. Results Compared with white NSTEMI patients, Asians (n = 307) were younger; more frequently had hypertension, diabetes and renal insufficiency; and were less likely to have had a prior myocardial infarction, but there were no significant differences in rates of cardiac catheterization or revascularization during the index hospitalization between the 2 groups. At 30 days, Asian and white patients had a similar risk-adjusted mortality (9.5% vs 9.9%, P =.77), but by 1 year, Asian patients had a significantly lower risk-adjusted mortality (20.9% vs 24.5%, adjusted hazard ratio 0.64, 95% CI 0.50-0.82). Compared with white patients, Asians also had a lower adjusted 1-year cardiovascular readmission risk (37.1% vs 42.1%, adjusted hazard ratio 0.79, 95% CI 0.64-0.98). Conclusions Despite similar inhospital treatments, Asian NSTEMI patients had lower mortality and cardiovascular readmission risks at 1 year, compared with white patients. Further study is needed to determine whether intrinsic ethnic differences or differential longitudinal prevention strategies explain these differences in long-term outcomes.