Population based study on the prevalence of the stages of heart failure

Heart failure (HF) is a major health issue. The heterogeneous nature of the syndrome impairs agreement on a standard definition. The high prevalence of HF with preserved left ventricular (LV) systolic function and asymptomatic LV systolic dysfunction, and the need for objective evidence of cardiac structural or functional abnormalities for HF diagnosis increase the difficulty in achieving a consensual definition. We aimed at estimating the age and sex specific prevalence of the American College of Cardiology (ACC)/American Heart Association (AHA)1 stages of HF in a representative sample of non-institutionalised adults from Porto, Portugal. Within a population health survey (participation 70%),2 we measured the prevalence of HF among participants aged ⩾ 45 years.2 The local ethics committee approved the study. Participants provided written informed consent. Hypertension was defined as blood pressure ⩾ 140/90 mm Hg or treatment with medication, and diabetes mellitus was defined as self reported or fasting blood glucose ⩾ 7 mmol/l. The metabolic syndrome was defined according to the National Cholesterol Education Program-Adult Treatment Panel III, obesity as body mass index ⩾ 30 kg/m2, and excessive alcohol intake as > 100 or > 80 g/day in men and women, respectively. Coronary artery disease was defined as self reported diagnosis of angina or myocardial infarction or pathological Q waves on ECG. Chronic lung disease was defined as previous chronic bronchitis or moderate to severe obstruction …