Accuracy of ankle-brachial index using an automatic blood pressure device to detect peripheral artery disease in preventive medicine

Abstract

Background: Previously, we validated determination of ankle-brachial index using an automatic blood pressure device.

Aim: To test the feasibility and accuracy of the automatic method in assessing pathological ankle-brachial indexes in routine preventive examinations.

Methods: Two physicians enrolled 354 subjects (74% men) randomly for automatic ankle-brachial index measurements using an OMRON HM 722 device. Ankle-brachial index was calculated by dividing the highest value obtained at each ankle by the highest arm value. Each subject with an abnormal (less than 0.90) automatic index and the six subsequent subjects underwent Doppler index determination.

Results: Automatic ankle-brachial index determination was possible in both ankles in 350 subjects (99%; mean time 8.1+/-2.1 minutes). The incidence of abnormal automatic ankle-brachial index was 8% (n=28). Correlations between the automatic and Doppler methods were good in left and right legs (r=0.84 and 0.78, respectively; p<0.001). In subjects with an abnormal automatic index, correlations with Doppler indexes were good in both legs (r=0.67, p<0.001). In terms of detecting an abnormal index in a routine preventive examination, the automatic method had good sensitivity (92%), specificity (98%), positive predictive value (86%), negative predictive value (99%) and accuracy (97% compared with the Doppler method). Good results were obtained in subjects with an abnormal index in terms of agreement and concordance with the Doppler method (kappa=0.87).

Conclusions: The use of a commercially available automatic blood pressure device to detect peripheral artery disease appears feasible and quick in routine medical examinations.