Heart rate adjustments and analysis of recovery patterns of ST-segment depression in type 2 diabetes

Aims To investigate the diagnostic value for coronary artery disease (CAD) detection of evaluating time- and heart rate (HR)-related ST-segment changes (the ST/HR-slope) and the post-exercise recovery pattern (the ST/HR-recovery loop) in patients with type 2 diabetes mellitus (T2DM). Methods and results Ninety-one patients (22 female, age 59 ± 9 years) with T2DM (diabetes duration 6 ± 6 years) performed an exercise ECG-test that was evaluated using the ST/HR slope (cut-off ≤ − 2.4 μV/bpm) and -recovery loop patterns (abnormal versus normal) and compared to the conventional ≥ 1 mm ST-segment depression criterion and dobutamine stress echo-cardiography, all evaluated against coronary angiography irrespective of stress test results. Coronary angiography revealed CAD in 20 men and 3 women (25%). Sensitivity for the conventional exercise test and stress echocardiography was low (0.35 and 0.30), but increased significantly using the ST/HR-slope (0.45), the recovery loop (0.86) or the combined ST/HR slope and recovery loop criterion (0.91). The associations between angiographic CAD-detection and the different tests expressed by the Odds ratio demonstrated an added value of performing ST/HR analysis both over pre-test CAD risk profile and the established techniques. Conclusion T2DM patients capable of performing an exercise test could be assessed with the ST/HR-analysis for selecting patients to angiography. However, further studies including a higher number of patients are needed to confirm the diagnostic value of this approach.