COMPARISON BETWEEN QT-INTERVAL PARAMETERS IN TYPE 2 DIABETIC AND NON-DIABETIC PATIENTS IN NON-ST SEGMENT ELEVATION MI

Background: Diabetes mellitus is known to increase cardiovascular risk and exacerbate complications during acute coronary events. QT interval abnormalities have been linked to adverse cardiac outcomes, particularly in diabetic individuals. Evaluating QT interval parameters in patients with non-ST segment elevation myocardial infarction (NSTEMI) may offer valuable insight into arrhythmic risk and guide clinical decision-making. This study aimed to compare QT interval characteristics between type 2 diabetic and non-diabetic patients presenting with NSTEMI to better understand this electrophysiological interplay. Objective: To compare QT-interval parameters in type 2 diabetic and non-diabetic patients with NSTEMI. Methods: This quasi-experimental study was conducted at the Department of Cardiology, Khyber Teaching Hospital, Peshawar, over a six-month period from July 11, 2024, to January 10, 2025. A total of 58 patients aged 35 to 80 years diagnosed with NSTEMI were enrolled and categorized into two groups: diabetic (n=29) and non-diabetic (n=29). Type 2 diabetes status was confirmed using HbA1c (>6.5% for diabetics, <5.5% for non-diabetics). A standard 12-lead ECG was obtained from all participants. QT max, QT min, QTc max, QTc min, QT dispersion (QTd), and corrected QT dispersion (QTcd) were measured. Mean values were compared between the groups using an independent samples t-test. SPSS version 26.0 was used for data analysis. Results: QTd was significantly higher in diabetics (47.31 ± 7.74 ms) than in non-diabetics (38.83 ± 5.78 ms, p<0.001). QTc min was also significantly prolonged in diabetics (53.00 ± 8.62 ms) compared to non-diabetics (41.58 ± 6.54 ms, p<0.001). QTc max showed a non-significant elevation in diabetics (425.83 ± 36.52 ms) versus non-diabetics (414.83 ± 19.21 ms, p=0.157). QTcd values were higher in diabetics (372.82 ± 37.49 ms) than non-diabetics (373.24 ± 22.90 ms) but not statistically significant (p=0.960). Conclusion: QT interval parameters, particularly QTd and QTc min, were significantly prolonged in diabetic patients with NSTEMI, suggesting a heightened risk of ventricular repolarization disturbances in this group. These findings support the use of ECG-based QT metrics for enhanced risk stratification in diabetic cardiac patients.