Cardiovascular disease recurrence and long-term mortality in a tri-ethnic British cohort

OBJECTIVE: Ethnic differences in cardiovascular disease incidence, but not cardiovascular disease recurrence, are reported. We characterised long-term risk of major adverse cardiovascular event (MACE) and mortality following a non-fatal cardiovascular event in a British cohort of South Asians, African Caribbeans and Europeans. METHODS: We identified index and recurrent cardiovascular events and mortality between 1988 and 2017 using hospital records and death registry. Using multivariable hazards models, we separately calculated the adjusted HR of MACE and death following index event, adjusting for demographics, vascular and lifestyle risk factors. Using interaction terms, we evaluated if decade of index event modified the association between ethnicity and outcomes. RESULTS: South Asians were younger at the index event (median age 66 years, n=396) than Europeans (69 years, n=335) and African Caribbeans (70 years, n=70). During 4228 person-years, of the 801 patients, 537 developed MACE and 338 died, with the highest crude rate of MACE in South Asians. On adjustment of baseline factors, compared with the Europeans, the higher risk of MACE (HR 0.97, 95% CI 0.77 to 1.21) and the lower risk of mortality (HR 0.95, 95% CI 0.72 to 1.26) in South Asians was eliminated. African Caribbeans had similar outcomes to Europeans (HR MACE 1.04, 95% CI 0.74 to 1.47; and HR death 1.07, 95% CI 0.70 to 1.64). Long-term survival following an index event improved in South Asians (p(trend) 0.02) and African Caribbeans (p(trend) 0.07) compared with Europeans. CONCLUSIONS: Baseline vascular risk factors explained the observed ethnic variation in cardiovascular disease recurrence and long-term mortality, with a relative improvement in survival of minority ethnic groups over time.