Prolonged Tp-E Interval and Tp-E/Qt Correlates Well with Modified Rodnan Skin Severity Score in Patients with Systemic Sclerosis

Abstract

Background: Ventricular arrhythmias can be seen in systemic sclerosis (SSc) patients and are thought to be a result of fibrosis or ischemia of the ventricular myocardium. Tp-e interval and Tp-e/QT ratio are electrocardiographic (ECG) indices to predict ventricular tachyarrhythmia and cardiovascular mortality. We aimed to evaluate Tp-e interval and Tp-e/QT ratio in patients with SSc. Methods: A total of 107 patients with SSc (mean age, 48.6 +/- 14.0 years; 96 females) and 100 healthy controls (mean age, 49.4 +/- 8.6 years; 90 females) were enrolled. The standard 12-lead ECG was recorded; QTc, Tp-e interval and Tp-e/QT ratio were measured. Modified Rodnan skin severity score (MR-SSS) calculated for all SSc patients. Results: Tp-e interval (90.7 +/- 23.8 ms vs. 84.0 +/- 20.6 ms, p = 0.032) and Tp-e/QT ratio (0.20 +/- 0.05 vs. 0.18 +/- 0.04, p = 0.007, respectively) were significantly prolonged in SSc patients than in the control group. Pearson's correlation analyses revealed positive correlations of MR-SSS with QTc (r = 0.427, p = 0.001), Tp-e interval (r = 0.620, p = 0.001) and Tp-e//QT ratio (r = 0.615, p = 0.001). MR-SSS (beta = 2.108, p = 0.001) and CRP (beta =2.273, p = 0.027) were found to be significant independent predictors of Tp-e interval. Similarly, MR-SSS (beta = 0.004, p = 0.001) was only a significant independent predictor of Tp-e/QT ratio among patients with SSc. Conclusions: The patients with SSc had a prolonged Tp-e interval and Tp-e/QT ratio compared with normal subjects. Furthermore, this prolongation was well correlated with clinical severity score among patients with SSc. Ventricular repolarization dispersion as a predictor of ventricular arrhythmias was found to be diminished in patients with SSc. Patients with SSc, particularly with higher MR-SSS, should be followed closely for adverse cardiovascular outcomes.