Usefulness of exercise stress test in early diagnosis of coronary artery disease in diabetic patients

Introduction: Treadmill test (TMT) is a safer, cheaper, reliable, and easily available noninvasive screening tool for the early detection of coronary artery disease (CAD) in diabetic patients. Materials and Methods: 150 patients suffering from type 2 diabetes mellitus without established clinical diagnosis of CAD attending cardiology outpatient department at a tertiary care center of Northwest India who fulfilled the inclusion and exclusion criteria during the study period were enrolled in the study. Subjects were classified into three groups based on their symptoms and electrocardiogram (ECG) findings. Group 1 ( n = 50): Cases who had no symptoms suggestive of CAD and had a normal ECG, Group 2 ( n = 50): Cases who were asymptomatic but resting ECG showed some abnormality (ST-T changes), and Group 3 ( n = 50): Cases who were symptomatic for CAD (typical or atypical) with either normal or abnormal resting ECG. The TMT was done using a computerized TMT machine model and continuous ECG recording was taken. Results: In Group 1, 18% were TMT positive and 82% were TMT negative, in Group 2, 34% were TMT positive and 66% were TMT negative, and in Group 3, 50% were TMT positive and 50% were TMT negative. Hence, out of the three groups, Group 3 has a proportionally, significantly higher number of TMT-positive cases and this difference in TMT positivity was statistically significant. Conclusion: Exercise stress test can be widely used test as a test for early diagnosis of ischemic heart disease in diabetic patients.