Association between Tpeak-Tend interval/ QT interval (Tp-e/QT ratio) and prognosis in patients with acute pulmonary embolism

Background: Risk stratification of patients with acute pulmonary embolism (PE) allows assessment of individual prognosis and guides therapeutic decision making. Several electrocardiographic (ECG) markers measuring the arrhythmogenic substrate(s) in ventricular myocardium are used to identify the high-risk patients with acute PE. However studies on Tp-e/QT ratio in patients with acute PE are lacking therefore the present study is aimed to evaluate the in hospital prognostic significance (death and in hospital adverse clinical events [ACE]) of Tp-e/QT ratio at admission in acute PE patients. Materials and methods: This was a retrospective study that included adult patients who had been diagnosed with acute PE and were treated at our hospital between January 2012 and March 2016. After considering inclusion and exclusion criteria, data was collected from eligible patients. All ECG recordings were digitalized and evaluated by a computer based program. Tp-e and QT intervals were measured from all precordial leads and mean value is calculated. Statistical analysis was performed using SPSS 17.0. Receiver operator characteristic (ROC) curves were computed for the Tp-e/QT ratio to assess the optimal cutoff values for predicting mortality and ACE. Univariate logistic regression analysis for the predictors of in hospital events (death and in hospital ACE) in the study population was done. The statistical significance was considered for a p-value <0.05. Results: A total of 48 patients were included in the study with mean age of 37.95 years (±13.86) and male: female ratio of 1.18:1. Patients with pulmonary embolism have mean Tp-e/QT ratio of 0.25 and the range of Tp-e/QT ratio was 0.18 to 0.29. In regression analysis, a Tp-e/QT ratio ≥0.26 increased the risk of death (P = 0.03) and a Tp-e/QT ratio ≥0.25 increased the risk of ACE (P = 0.01) significantly. Conclusion: In acute Pulmonary Embolism, Tp-e/QT ratio is a simple and useful tool in predicting the patients at high risk of suffering adverse clinical events and death. Hence this ratio may serve as a prognostic marker in these patients.