[Ankle brachial pressure index (ABPI): color-Doppler versus ultrasound Doppler correlation study in 98 patients after...

Ankle Brachial Pressure Index (ABPI) by Doppler ultrasound is the gold standard non invasive method for screening of peripheral arterial disease (PAD). This reference method is little used in routine practice, particularly by vascular disease specialists since the most recent ultrasound devices no longer have continuous wave probes. The purpose of our survey was to assess interobserver reproducibility of color-Doppler measurements made in a first population, then second, to assess the correlation between ABPI measurements made with color-Doppler and with ultrasound Doppler in a second population.

One hundred twenty patients meeting screening criteria for AOMI defined by the French Health Authorities (HAS, 2006) participated in the study between October 2010 and April 2011 in the Echo Doppler and Vascular Medicine unit of the Brest University teaching hospital: 22 patients for interobserver reproducibility and 98 for color-Doppler - continuous Doppler correlation study. Two independent operators measured the ABPI index in each of the 98 patients using color-Doppler and continuous Doppler in random order, producing 353 measurements. Reliability and reproducibility were assessed using the intraclass correlation coefficient of correlation (ICC) determined with Spearman and the Bland-Altman methods.

The ABPI was less than 0.90 in 62% of patients. The color-Doppler reproducibility study showed a mean difference of 0.02 [95% CI: -0.02 to 0.17] using the Bland Altman method with ICC equal to 0.89 (P<0.001). For the intermethod correlation study, the mean difference was 0.03 [95% CI: -0.17 to 0.23], with ICC equal to 0.84 (P<0.001).

Color-Doppler could be an alternative to Doppler ultrasound for PAD screening or follow-up, depending on the results of further evaluations in larger populations.