Evaluation of Tpeak to end/QT and Tpeak to end/QTc ratios in patients with STEMI undergoing percutaneous intervention vs. thrombolytic therapy

Abstract

IntroductionThe patients with ST-segment Elevation Myocardial Infarction (STEMI) are significantly at increased risk of arrhythmia. Repolarization of myocardium has been evaluated by a series of electrical parameters including T wave peak to T wave end (Tp-Te) and Tp-Te/QT ratio. Which were compared with survival outcomes between two groups of STEMI patients treated with Primary Percutaneous Coronary Intervention (PPCI) and recombinant Tissue Plasminogen Activator (r-TPA). MethodsIn this prospective study, 188 patients with STEMI were included in the study. 12‑Lead ECGs were obtained from all patients on time of admission and after 24 h after treatment. After dividing the patients into two groups based on their type of treatment (PPCI or r-TPA), The Tp-Te/QT and Tp-Te/QTc ratios were calculated using ECG records. The survival outcomes were compared between two groups. Results95 patients (50.5%) underwent PPCI and 93 patients (49.5%) received r-TPA. Tp-Te/QT and Tp-Te/QTc ratios after administration of the treatments were significantly decreased in both groups (P-value = .001) with lower Tp-Te/QT and Tp-Te/QTc ratios in PPCI group (P-value = .001). 7 patients in PPCI group (7.3%) and 16 patients in r-TPA group (17.2%) were died during their hospitalization period (P-value = .04). The best combination of sensitivity and specificity of post treatment Tp-Te/QT ratio was at cutoff points of 29.4 with 82% sensitivity and 83% specificity. ConclusionOur study demonstrated that Tp-Te/QT and Tp-Te/QTc ratios decrease significantly after both PPCI and r-TPA therapies, but with PPCI these indexes decrease more than r-TPA, resulting a better survival outcome in patients with STEMI.