Prediction of Coronary Artery Disease using Ankle Brachial Pressure Index in Patients with Diabetes Mellitus: A Cross-sectional Study

Introduction: Diabetes mellitus confers a tenfold risk of cardiovascular disease due to atherosclerosis. Screening a large number of patients for Coronary Artery Disease (CAD) in susceptible population groups is required. Ankle Brachial Pressure Index (ABPI) is a non invasive tool for identifying atherosclerosis and peripheral artery disease and can be used in large population studies. Hence the present study attempted to assess the applicability of ABPI as a tool for prediction of CAD in diabetic patients.

Aim: To calculate the ABPI in patients of diabetes mellitus and to assess the association of ABPI value with presence of CAD, duration of CAD and with the microvascular complications of diabetes mellitus.

Materials and Methods: This cross-sectional study was conducted at MMIMSR, Mullana from December 2019 to July 2021. A 100 patients suffering from type 2 diabetes mellitus for more than five years duration were included. Patients were divided into two groups based on the presence or absence of CAD. ABPI was calculated in each patients and its correlation was assessed with CAD and association with microvascular complications of diabetes mellitus. The correlation assessed using Pearson correlation test. The mean was compared in with respect to independent t-test (for two groups).

Results: Out of 100 patients there were 78 males and 22 females of mean age 60.64±10.97 years. Microvascular complications were present in 35% cases. Past history of CAD was present in 58%, stroke in 9%, hypertension in 15% and chronic kidney disease in 8%. Electrocardiogram (ECG) changes of CAD were observed in 56% while 2D-ECHO showed Regional Wall Motion Abnormality (RWMA) in 57 cases while 18 had angiographic evidence. Mean ABPI was 0.79 and 1.17 in the CAD and non CAD group respectively which was significant. A negative correlation was observed with ABPI and duration of CAD in years with Pearson correlation value of-0.260 (p-value 0.049).

Conclusion: ABPI was also found to be negatively correlated with the duration of CAD and was significantly lower in diabetic patients with microvascular complications of diabetes. ABPI had a senstivity of 84.5% and specificity of 90.5% in prediction of CAD in patients suffering from diabetes.