The Diagnostic Accuracy of Ankle Brachial Index in Relation to Coronary Computed Tomography in Coronary Artery Disease

Background: Arterial stiffness and loss of recoil indicate arterial aging and increase cardiovascular risk, particularly for ischemic heart disease. Advances in coronary computed tomography angiography (CCTA) enhance the detection of coronary artery disease (CAD) through high-quality imaging and plaque analysis. This study's objective is evaluating the ankle-brachial index (ABI) accuracy in diagnosing CAD compared to CCTA. Methods: A prospective, observational study was executed with 200 participants who underwent ABI measurement and CCTA, with CAD severity assessed via the Gensini score. In accordance with Gensini scores, the patients were split into two distinct groups, Group 1: low Gensini score and Group 2: high Gensini score. Results: The mean ABI was 96.26 ± 9.3%, with 29% of patients showing abnormal readings. Patients with abnormal ABI were significantly older and exhibited a higher prevalence of hypertension (60.5%), diabetes (43%), and dyslipidemia (52%). The ABI effectively distinguished between normal and abnormal readings, achieving an AUC of 0.866 at a cutoff of ≤ 98%, with 100% sensitivity and 55.63% specificity. Coronary artery calcium (CAC) scores showed superior diagnostic performance with an AUC of 0.920 at a cutoff of >169, yielding 91.38% sensitivity and 84.29% specificity. The Gensini score demonstrated an AUC of 0.723 at a cutoff of >94, providing 70.69% sensitivity and 76.60% specificity. Conclusion: CAC and Gensini scores were significantly elevated in the abnormal ABI group highlighting a clear correlation between lower ABI values and greater CAD severity. CAC scores showed excellent diagnostic accuracy, while ABI had high sensitivity but lower specificity for CAD assessment. The Gensini score is used as invasive method to assess severity of CAD correlated to Calcium scoring and ABI. Overall, the findings support using both ABI and CAC scoring in evaluating CAD, especially in at-risk groups.