Prevalence of an abnormal ankle-brachial index in relation to the cardiovascular risk estimated by the Framingham function

BACKGROUND AND OBJECTIVE: The measurement of the ankle-brachial index (ABI) is a straightforward method for the detection of atherosclerosis in the lower limbs. An abnormal ABI (< 0.9 or > 1.4) is associated with the development of cardiovascular disease and cardiovascular and all-cause mortality. Despite this, its measurement in clinical practice is underused. The objective of the present study was to evaluate the relation of the ABI with the cardiovascular risk determined by traditional risk functions in a population in primary prevention. PATIENTS AND METHOD: 1001 subjects without known cardiovascular disease attended in primary care were invited to participate in the study. Cardiovascular risk and ABI measurements were calculated in all participants. calculated in all participants. RESULTS: A low (< 0.9) ABI was found in a 3.8% of the participants, 3.9% females and 3.6% males. An abnormal ABI (< 0.9 or > 1.4) was found in 6.4% of all subjects, 5.2% females and 8.8% males. In a multivariable analysis age (OR = 1.09 for each year; 95% CI 1.03-1.15), smoking habit (OR = 2.96; 95% CI 1.51-5.80), HDL-cholesterol levels (OR = 0.98 for each 95% CI, 0.95-0.99) and hypertension (OR = 1.80; 95% CI, 1.05-3.06) were related with an abnormal ABI. Subjects were divided according to their risk stratification. The percentage of low, moderate and high risk individuals with an abnormal ABI was 2.6%, 8.7% and 14.9% respectively. CONCLUSIONS: In primary prevention, one in ten individuals with moderate risk and one in six individuals with high risk have an abnormal ABI. In these subjects there is an indication for intensive preventive strategies and antiagregation.