Ethnic and sex inequalities in premature coronary artery disease across disaggregated South Asian and Black subgroups in England: a population-based cohort study

Abstract Background Premature, or early-onset, coronary artery disease (CAD) carries lifelong consequences. Ethnic inequalities in CAD are established in the UK, but risk estimates mostly derive from events after middle age, while ethnicity is aggregated for South Asian and Black populations. Disaggregated, sex-specific risk estimates would permit better recognition and more targeted prevention. Methods We used Clinical Practice Research Datalink (CPRD) Aurum, an English primary care database linked to hospital, mortality, and deprivation data. We included adults aged 18-45 of White European, South Asian (Indian, Pakistani, Bangladeshi), or Black (African, Caribbean) ethnicity, followed for up to 20 years. Incident premature CAD (onset [&le;]45) was a first myocardial infarction or coronary revascularisation. We estimated age-adjusted and fully adjusted incidence rate ratios (IRRs) versus White Europeans by Poisson regression, testing an ethnicity-sex interaction. Findings Among 14.8 million adults contributing 80.9 million person-years, 16,001 premature CAD events occurred (77.6% in men). In men, the combined South Asian age-adjusted IRR was 1.87 [95% CI 1.77, 1.99], ranging from 1.39 [1.28, 1.50] in Indian to 2.79 [2.52, 3.07] in Bangladeshi men, persisting after full adjustment and already evident at ages 18-26. The combined Black IRR was 0.64 [0.57, 0.71], lowest in African (0.57[0.50, 0.65]) and highest in Caribbean men (0.82 [0.68, 0.98]). In women, the combined South Asian IRR showed no overall excess (1.10 [0.95, 1.26]), concealing a clear excess in Pakistani women (1.56 [1.29, 1.89]). The ethnicity-sex interaction was significant (p<0.001); the male-to-female ratio was highest in Bangladeshi individuals (8.4:1 versus 3.3:1 in White Europeans). Interpretation Aggregated ethnic categories conceal sex-specific subgroups at high risk of premature CAD, a risk already present in early adulthood. Current screening and health check programmes beginning at age 40, start too late to reach these higher-risk, underserved groups. Funding: Kusuma Trust and NIHR UCLH BRC.