Prognostic value of low ankle–brachial index in patients with hypertension and acute coronary syndromes

Abstract

Peripheral arterial disease (PAD) is associated with an increased risk of cardiovascular morbidity and mortality. Nevertheless, many patients are asymptomatic, and this condition frequently remains underdiagnosed. An ankle-brachial index (ABI) of less than 0.9 is a noninvasive and simple marker in the diagnosis of PAD and is also predictive of target organ damage in hypertension. The prognostic value of such measurements in hypertensive patients with acute coronary syndrome (ACS) is unknown. The Prevalence of Peripheral Arterial Disease in Patients with Acute Coronary Syndrome registry is a multicentre, observational and prospective study that aims to describe the prevalence of and prognosis for PAD, diagnosed by ABI in hypertensive patients with ACS. One thousand one hundred and one hypertensive patients with ACS and at least 40 years of age were prospectively studied. Mean age of the population was 67.4 (11.4) years, and 67.7% were men. The prevalence of ABI less than 0.9 was 42.6% (469 patients). This subgroup was significantly older, had a higher prevalence of diabetes, previous coronary heart disease or stroke, left ventricular hypertrophy and more severe coronary lesions. Hospital mortality was higher in hypertensive patients with ABI less than 0.9 (2.3 vs. 0.2%; P< 0.01). An ABI less than 0.9 was associated with an increased risk of heart failure after ACS (odds ratio, 1.4; P=0.04), higher hospital mortality (odds ratio, 13.0; P=0.03) and the composite endpoint of mortality, heart failure and angina (odds ratio, 1.4; P=0.03). Asymptomatic PAD is highly prevalent in hypertensive patients with ACS. An ABI less than 0.9 identifies a subset of patients with more extensive target organ damage and higher risk of hospital cardiovascular complications after an ACS.