Differences in short-term versus long-term outcomes of older black versus white patients with myocardial infarction: findings from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of American College of Cardiology/American Heart Association Guidelines (CRUSADE)

Abstract

Background: Blacks are less likely than whites to receive coronary revascularization and evidence-based therapies after acute myocardial infarction, yet the impact of these differences on long-term outcomes is unknown.

Methods and results: We linked Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of American College of Cardiology/American Heart Association Guidelines (CRUSADE) registry data to national Medicare claims, creating a longitudinal record of care and outcomes among 40 500 patients with non-ST-segment-elevation myocardial infarction treated at 446 hospitals to examine mortality and readmission rates (mean follow-up, 2.4 years) among black and white patients. Relative to whites (n=37 384), blacks (n=3116) were more often younger and female; more often had diabetes mellitus and renal failure; and received less aggressive interventions, including cardiac catheterization (60.7% versus 54.0%; P<0.001), percutaneous coronary intervention (32.1% versus 23.8%; P<0.001), and coronary bypass surgery (9.2% versus 5.7%; P<0.001). Although blacks had lower 30-day mortality (9.1% versus 9.9%; adjusted hazard ratio, 0.80; 95% confidence interval, 0.71-0.92), they had higher observed mortality at 1 year (27.9% versus 24.5%; P<0.001), although this was not significant after adjustment on long-term follow-up (hazard ratio, 1.00; 95% confidence interval, 0.94-1.07). Black patients also had higher 30-day (23.6% versus 20.0%; P<0.001) and 1-year (62.0% versus 54.6%; P<0.001) all-cause readmission, but these differences were no longer significant after risk adjustment on 30-day (hazard ratio, 1.02; 95% confidence interval, 0.92-1.13) and long-term (hazard ratio, 1.05; 95% confidence interval, 1.00-1.11) follow-up.

Conclusions: Although older blacks with an acute myocardial infarction had lower initial mortality rates than whites, this early survival advantage did not persist during long-term follow-up. The reasons for this are multifactorial but may include differences in comorbidities and postdischarge care.

Keywords: continental population groups; healthcare disparities; myocardial infarction; patient outcome assessment.