[Ankle-brachial index to detect peripheral arterial disease: concordance and validation study between Doppler and an oscillometric device]

Abstract

Background and objective: To evaluate the sensitivity and specificity of ankle-brachial index (ABI) determined by oscillometry, using a Doppler ultrasound probe as a gold standard. We also aimed to evaluate the agreement between both methods.

Patients and method: Right and left ABI measurements (ABIr,ABIl) with oscillometric (OMRON-705-CP) and Doppler (DIADOP-50) devices in hypertensive patients without peripheral arterial disease.

Results: One hundred patients, 61 women, 66.4 (SD 10.9) year-old, smokers 16%, diabetics 38%. Oscillometric and doppler ABI could be calculated in 83% and 93% of patients, respectively. Oscillometric ABIr and ABIl measurements were <0.9 in 9.6% (CI 95%, 4.2-18.1) and 8.4% (CI 95%, 3.4-16.6), respectively, and Doppler measurements were 10.8% (CI 95%, 5.3-18.9) and 15.4% (CI 95%, 8.7-24.5) respectively. The oscillometric ABIr and ABIl sensitivity was 37.5% (CI 95%, 13.7-69.4) and 20.0% (CI 95%, 5.7-51.0) respectively, and the specificity was 93.0% (CI 95%, 84.6-97.8) and 97.1% (CI 95%, 89.9-99.2), respectively. The intraclass correlation (index Doppler/oscillometric device) was 0.64 (CI 95%, 0.44-0.77) for ABIr and 0.62 (CI 95%, 0.41-0.76) for ABIl.

Conclusions: About 8.4-15.4% of hypertensive patients attended have an abnormal Doppler ABI measurement. There is not a good concordance between Doppler and oscillometric ABI measurements. This oscillometric device does not seem useful as an ABI screening method.