Integrating Toe Brachial Index and longitudinal strain echocardiography for detecting coronary artery disease in patients with diabetic foot syndrome

Coronary artery disease (CAD) is a common problem amongst diabetic foot syndrome (DFS) patients, associated with peripheral arterial disease. This analytic cross-sectional study investigates the diagnostic efficacy of the Toe Brachial Index (TBI) in the detection of CAD in 62 DFS patients. The presence of CAD was assessed by longitudinal strain echocardiography, a sensitive method that provides a more accurate measure of intrinsic left ventricular contractility than left ventricular ejection fraction, especially in diabetic patients. Univariate and multivariate logistic regression identified CAD-associated factors. Receiver operating characteristic curve evaluated TBI and toe pressure's diagnostic performance for CAD. p-Values < 0.05 were considered significant. There was a significant association between TBI and CAD, with each 0.01 increase in TBI associated with a 15% decrease in the odds of CAD development (odds ratio = 0.85, 95% CI: 0.72–0.99, p = 0.039). TBI demonstrated an area under the curve of 0.854, a sensitivity of 80.0% and a specificity of 66.7% at a cut-off of 0.69. Additionally, toe pressure exhibited an area under the curve of 0.845, sensitivity of 74.0% and specificity of 75.0% at a cut-off of 68.0 mmHg. Overall accuracy for TBI and toe pressure was 77.4% and 74.2%, respectively, indicating their potential for CAD risk stratification in the DFS population. This study highlights a significant association between low TBI and the presence of CAD in DFS patients. Consequently, TBI emerges as a valuable screening tool for identifying CAD within this population.