Background: Low ankle-arm systolic blood pressure index is strongly correlated with various cardiovascular risk factors. However, although the potential hazards of resulting coronary artery disease (CAD) are well established, no data is available regarding how ankle-arm index (AAI) and CAD severity are related.
Methods: This study enrolled 477 patients and all patients underwent coronary angiography and AAI measurements. Based on AAI values, patients were divided into study (AAI value of <0.9, 126 patients) and control groups (AAI value of >or=0.9, 351 patients).
Results: Among baseline characteristics, the study group showed a significantly older and higher female ratio than the control group. The presence of hypertension, diabetes mellitus (DM), current smoking status and LDL-cholesterol level differed significantly between these two groups. Mean number of lesions and target vessel involvement were significant different between the study and control group (2.6+/-1.1 vs. 1.9+/-1.0, p<0.0001; 2.0+/-0.8 vs. 1.6+/-0.7, p<0.0001). Percentages of lesion sites on ostial and proximal portions were markedly high in the study group than in the control group. Significant differences also emerged in the complex stenotic lesions (B2 or C) and lesion morphology (calcified, chronic total occlusion, irregular, bifurcation and diffuse) of these two groups. Multivariate logistic regression analysis, showed that AAI is a statistically significant independent predictor for lesion site, complex stenotic lesions and lesion morphology with Odds ratios (ORs) of, respectively, 1.728, 2.880 and 2.71.
Conclusions: The AAI is a useful non-invasive tool for the prediction of CAD severity.