Ethnic disparities in mortality from acute coronary syndrome: a multicenter cohort study

Abstract Introduction Previous studies on ethnic disparities in mortality from acute coronary syndrome (ACS) have primarily focused on 30-day mortality, revealing significant differences, with higher mortality rates in Black and Asian populations compared to White populations. However, many of these studies have not fully accounted for multiple comorbidities or the use of invasive management, such as coronary angiography, and have often combined both ST-elevation myocardial infarction (STEMI) and non-ST-elevation ACS (NSTE-ACS) patients. Purpose We determined whether ethnic disparities in mortality from STEMI or NSTE-ACS exist at 30 days and 1 year, adjusting for comorbidities and invasive management. Methods A retrospective cohort study was conducted using the National Institute for Health Research Health Informatics Collaborative Cardiovascular dataset (1,2), including all consecutive White, Asian, or Black patients who experienced an ACS at five hospitals between 2010 and 2017. Cox proportional hazards models were used to assess mortality, adjusting for age, gender, creatinine, haemoglobin, troponin, white cell count, a history of atrial fibrillation, heart failure, previous myocardial infarction, obstructive lung disease, hypertension, or diabetes, and whether invasive management was undertaken during their index admission. Invasive management was defined as coronary angiography, with or without subsequent revascularisation. An interaction between invasive management and ethnicity was also considered in the Cox model. All patients were followed until death or censoring in April 2017. Results A total of 9,216 patients with ACS were included, consisting of 7,745 (84.1%) White, 965 (10.5%) Asian, and 506 (5.5%) Black patients. Among the 2,845 (30.8%) patients who presented with STEMI, no significant differences in mortality were observed between ethnic groups at 30-day follow-up (Figure 1A). However, at 1 year, Black patients demonstrated a significantly higher mortality risk compared to White patients (hazard ratio 2.11, 95% confidence interval 1.12 to 3.96), but only after full adjustment for confounders, including a significant interaction between ethnicity and invasive management (p = 0.01) (Figure 1B). This increased risk was primarily observed among patients who did not undergo invasive management (2.12, 1.08 to 4.15), with no difference in mortality observed among those who received invasive management. Among the 6,371 patients with NSTE-ACS, Asian patients exhibited a higher mortality risk than Black patients at 30 days, with this trend reaching statistical significance at 1-year follow-up in adjusted analyses, while Black patients had a lower mortality risk than White patients at both time points (Figure 2). Conclusion Ethnic disparities in mortality from ACS remain evident at both 30-day and 1-year follow-up, with differing patterns observed for STEMI and NSTE-ACS, despite adjustments for comorbidities and invasive management.Figure 1.Mortality in STEMI Figure 2.Mortality in NSTEMI