Feasibility and reliability of ankle/arm blood pressure index in preventive medicine.

Despite its potential usefulness for assessing preclinical atherosclerosis and cardiovascular risk, the ankle/arm blood pressure index (AAI) has not yet been the matter of study evaluating its feasibility and reliability by nonspecialist doctors in a general population. This study was planned for two steps. In step 1, the measurement of AAI, (ratio between Doppler systolic pressure at the ankle for each lower limb and the highest value of Doppler systolic pressure of the two upper limbs), should be performed by 50 general practitioners (GPs), 50 social security center physicians, and 50 occupational health physicians in 3,000 male smokers, 40 to 59 years, without clinical cardiovascular disease. In step 2, AAI measurement, coupled with echography-Doppler of iliofemoral arteries, should be repeated by a specialist in all subjects with decreased AAI (<0.90) and the first two subjects with normal AAI recruited in step 1 by each nonspecialist. The number of physicians and subjects participating in step 1 was lower than planned (80 physicians and 962 subjects) with the greatest defect for GPs (six physicians and 35 subjects) and the prevalence of decreased AAI was low (28 subjects). AAI measurement was repeated in step 2 in only 12 subjects with decreased AAI in step 1 and in 124 subjects with normal AAI in step 1. Five of the six subjects with decreased AAI in step 2 also had decreased AAI in step 1 and 123 of the 130 subjects with normal AAI in step 2 also had normal AAI in step 1. As regards echographic stenosis, decreased AAI had a sensitivity of 44% and a specificity of 98%. AAI seems more feasible for occupational health physicians and social security center physicians and AAI is also reliable for nonspecialists previously trained, but its predictive value as regards echographic stenosis is poor in asymptomatic subjects, which may limit its usefulness for detecting preclinical atherosclerosis.