P3343Association of minority status with mortality and hospital readmission in patients with ischemic cardiomyopathy in the STICH trial

Background Racial and ethnic minorities with coronary artery disease (CAD) suffer worse outcomes than their non-minority counterparts, including increased mortality and hospital readmissions. Proposed explanations include impaired access to care, reduced quality of care, comorbidity burden and medication access. Study of the outcomes of minorities in randomized controlled trials (RCT) allows controlling for some of these factors. Purpose The purpose of the current study was to evaluate the impact of minority status on mortality and hospital readmission in patients enrolled in the Surgical Treatment for Ischaemic Heart Failure (STICH) trial. Methods STICH was a multicenter, international RCT of patients with an ejection fraction (EF) of 35% or less and CAD amenable to coronary artery bypass graft surgery (CABG) who were randomized to undergo CABG plus medical therapy or medical therapy alone. Median follow-up was 9.8 years. Minority status was defined by self-reported black race or Hispanic ethnicity. Optimal medical therapy (OMT) was the combination of at least 1 antiplatelet drug, a statin, a beta-blocker, and an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. The primary outcomes of interest were mortality and hospital readmission. Separate Cox proportional hazards models were constructed to examine the independent associations between minority status and mortality and readmission. Results Of 1212 patients randomized, 421 (35%) were members of a minority. CABG was the treatment assignment in 52.5% of minority participants whereas 47.5% were randomized to medical therapy (P=0.27). Minority patients were significantly younger than non-minority patients (57.8 vs 61.6 years, P=0.003). Sex, smoking status, and the prevalence of diabetes, hypertension, stroke and chronic kidney disease did not differ between minority and non-minority patients. Fewer minority patients had hyperlipidemia (49% vs. 66%, P<0.001), prior MI (72% vs 80%, P=0.003), atrial fibrillation (8.1% vs. 15%, P=0.001) or prior percutaneous coronary intervention (9% vs. 15%, P=0.004). Minority patients were less often on OMT at 30 days (56% vs. 66%, P=0.001), 1 year (70% vs. 76%, P=0.048) and 5 years (66% vs. 75%, P=0.002). Crude mortality rates were lower in minority patients (57% vs. 65%, P=0.004). However, minority status was independently associated with an increased hazard of mortality (HR 2.3, 95% CI: 1.5–2.5, P<0.001) but had no effect on rehospitalization (HR 1.01, 95% CI: 0.78–1.31, P=0.97). Conclusion Despite being a low risk population, minority status in the STICH trial was associated with a 2.3-fold increased hazard of mortality in patients with ischaemic cardiomyopathy. Additional research is urgently needed to delineate and address the causes of disparate outcomes among minority patients.