Left ventricular hypertrophy and mortality in ethnic minority groups in the UK: e-ECHOES study.

OBJECTIVES: Hypertension is the key modifiable cardiovascular risk factor but is underdiagnosed, and its scale in South Asian and African-Caribbean communities is unknown. Left ventricular hypertrophy (LVH) is a measure of target organ damage in uncontrolled hypertension. The study assesses LVH prevalence in South Asian and African-Caribbean communities and its impact on mortality.

METHOD: This study is based on the large prospective UK community Ethnic-Echocardiographic Heart of England Screening Study (E-ECHOES, age ≥45 years). Left ventricular mass index (LVMI) was calculated using echocardiography to establish LVH. The predictive value of LVH all-cause and cardiovascular mortality was assessed using Cox regression.

RESULTS: The study included 3200 South Asians (age 59 ± 10 years, 52% women, 45% had a history of hypertension, 5.8 ± 1.0-year follow-up). LVH was found in 1568 (49%), of whom 45% did not have hypertension diagnosis. On Cox regression, LVH was independently associated with all-cause mortality [hazard ratio 1.38, 95% confidence interval (95% CI) 1.01-1.88], cardiovascular mortality (hazard ratio 2.64, 95% CI 1.21-3.73). The projected overall hypertension prevalence was 82%, undiagnosed hypertension prevalence 37%. The study included 1858 African-Caribbeans (age 62 ± 12, 45% women, 45% had history of hypertension, 5.1 ± 0.9-year follow-up). LVH was found in 1186 (64%), of whom 32% did not have hypertension diagnosis. LVH was borderline associated with all-cause mortality (hazard ratio 1.57, 95% CI 1.01-2.44), but not cardiovascular mortality (hazard ratio 1.82, 95% CI 0.80-4.16). The projected overall hypertension prevalence was 78.5%, and undiagnosed hypertension prevalence was 20.8%.

CONCLUSION: UK South Asians and African-Caribbeans have a high prevalence of hypertension, which is often underdiagnosed and poorly controlled.