Ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction in the community: the Harrow heart failure watch.

OBJECTIVE: To assess ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction (LVSD) in the community.
DESIGN: Community cohort study. All patients underwent echocardiography and those found to have LVSD underwent myocardial perfusion imaging with or without coronary angiography to diagnose underlying coronary artery disease (CAD).
SETTING: Seven representative general practices in Harrow, UK, a community hospital, and a local district general hospital. PATIENTS: 1392 patients >or= 45 years old randomly selected from the computer records of seven general practices. MAIN OUTCOME MEASURES: The prevalence and aetiology of LVSD in the community, assessing differences between white and non-white populations, and the proportion of patients with LVSD with undiagnosed CAD.
RESULTS: 734 patients (53%) attended, 518 (71%) white and 216 (29%) non-white, the majority South Asian. Thirty nine patients (5.5%) had probable LVSD and 25 (3.5%) definite LVSD. No significant differences in prevalence were seen with ethnicity. CAD underlay most cases of LVSD. Non-white patients had a higher prevalence of CAD as the underlying aetiology of significant LVSD than white patients (100% v 56%, p = 0.04) and a trend towards less alcoholic cardiomyopathy. 8% of patients with LVSD had undiagnosed CAD.
CONCLUSIONS: LVSD is common. White and non-white patients have a similar overall prevalence of LVSD. Non-white patients, the majority South Asians in this study, have a higher prevalence of CAD as the underlying cause for LVSD than white patients. CAD underlies most cases of LVSD in the community, although it may be undiagnosed unless formally assessed.