Do we need to reappraise our method of interpreting the ankle brachial pressure index?

This prospective study aimed to investigate if there is a relationship between ankle brachial pressure index (ABPI) and brachial systolic pressure when measured using Doppler ultrasound. Sixty-two limbs (36 patients) in which arterial disease and diabetes mellitus could be excluded using published blood pressure and flow criteria were included in the study. All measurements were made with a Scimed PVL 50 (Bristol UK) using a revised version of the Whiston method and a one-minute treadmill walk. Statistical analysis was carried out using Pearson's product moment correlation and the t test. A relationship was found between the ABPI and brachial systolic pressure, with statistical analysis indicating that the ABPI was highest in hypotensive patients and lowest in hypertensive patients (r = -0.385, p < 0.01). This may suggest that the current practice of assigning one particular ABPI value as normal (1.00) is not reliable and that the way in which the index is interpreted needs to be reappraised.