Associations between family history and coronary artery calcium and coronary heart disease in British Europeans and South Asians.

BACKGROUND: The role of family history in determining excess risk of coronary heart disease (CHD) in South Asians compared with Europeans is unclear. We hypothesized that family history would be more strongly associated with CHD in South Asians.

METHODS: We performed cross-sectional analyses of 20-year follow-up data from SABRE (Southall And Brent Revisited) population-based study. Initial recruitment (1988-1991) was by random selection from general practitioners' lists in north-west London. 974 Europeans and 734 South Asians completed follow-up questionnaire (2008-2011) and had complete CHD and family history data. 831 participants without cardiovascular disease had complete coronary artery calcium (CAC) data.

RESULTS: South Asians with family history of CHD were more likely to have diagnosed CHD (odds ratio 1.71 [95% CI 1.21, 2.42]; p = 0.002) and more previous CHD events (regression coefficient 0.44 [0.16, 0.72]; p = 0.002) than those without family history, independent of biological and sociodemographic risk factors. Family history associations with diagnosed CHD/number of events were weaker in Europeans (odds ratio 1.11 [0.78, 1.57]; p = 0.562/regression coefficient 0.02 [-0.25, 0.30]; p = 0.878), largely explained by biological risk factors. South Asians with family history had modestly increased CAC burden compared with Europeans.

CONCLUSIONS: There were markedly stronger associations between family history and clinical CHD in South Asians, and a similar trend for subclinical CHD. Early preventive and therapeutic interventions are particularly important in South Asians with a family history of CHD.