Prevalence of left-ventricular systolic dysfunction and heart failure in the Echocardiographic Heart of England Screening study: a population based study.

BACKGROUND: Accurate data for prevalence rates for heart failure due to various causes, and for left-ventricular systolic dysfunction in all adults are unavailable. Our aim was to assess prevalence of left-ventricular systolic dysfunction and heart failure in a large representative adult population in England.
METHODS: Of 6286 randomly selected patients aged 45 years and older, 3960 (63%) participated in the study. They came from 16 randomly selected general practices. We assessed patients by history and examination, electrocardiography, and echocardiography. Prevalence of left-ventricular systolic dysfunction (defined as ejection fraction <40%) and heart failure was calculated for the overall population on the basis of strict criteria and, when necessary, adjudication by a panel.
FINDINGS: Left-ventricular systolic dysfunction was diagnosed in 72 (1.8% [95% CI 1.4-2.3]) participants, half of whom had no symptoms. Borderline left-ventricular function (ejection fraction 40-50%) was seen in 139 patients (3.5% [3.0-4.1]). Definite heart failure was seen in 92 (2.3%, [1.9-2.8]) and was associated with an ejection fraction of less than 40% in 38 (41%) patients, atrial fibrillation in 30 (33%), and valve disease in 24 (26%). Probable heart failure was seen in a further 32 (0.8% [0.6-1.1]) patients. In total, 124 (3.1% [2.6-3.7]) patients aged 45 years or older had definite or probable heart failure.
INTERPRETATION: Heart failure is often misdiagnosed or underdiagnosed in primary care. Our results suggest that assessment of left-ventricular function in patients with suspected heart failure could lead to more effective diagnosis and treatment of this disorder.