Utility of ankle–brachial pressure index/carotid intima-media thickness ratio in predicting presence and severity of coronary artery disease: A study from major center in Northeastern India

Abstract

Background: Studies have shown that carotid intima-media thickness (CIMT) and ankle–brachial pressure index (ABI) can be used as surrogate markers of coronary artery disease (CAD). However, whether studying the ratio of ABI and CIMT has any added value in predicting CAD when compared to either of them alone, has not been studied. Aims: The aim of the study is to compare CIMT and ABI as surrogate markers for the presence and extent of CAD and to investigate whether studying the ratio of ABI and CIMT has any incremental value in predicting CAD than either of them. Methods: We prospectively enrolled 235 stable, non-ACS patients who underwent CIMT and ABI measurements followed by diagnostic coronary angiography. Results: The mean age of the study population was 56.32 ± 10.14 years. CIMT was significantly higher in the CAD group compared to non-CAD group (0.91 ± 0.22 vs. 0.66 ± 0.15, P ≤ 0.0001). ABI was significantly lower in the CAD group compared to non-CAD group (1.07 ± 0.19 vs. 1.18 ± 0.14, P ≤ 0.0001). At an optimal cutoff value of ≥0.75 mm, CIMT showed better predictive values (sensitivity and specificity –72.3% and 79%, respectively) compared to ABI ≤0.9 (sensitivity and specificity – 21.53% and 96.19%, respectively). CIMT was the strongest independent predictor of CAD (P