Tpeak-Tend dispersion as a predictor for malignant arrhythmia events in patients with vasospastic angina

Background: Tpeak-Tend interval (Tp-e interval) in electrocardiogram(ECG) has been reported to predict malignant arrhythmia events (MAE) in ST-segment elevation myocardial infarction and ion channelopathy. Tp-e interval and other ECG parameters as predictors for MAE was evaluated in patients with vasospastic angina (VA). Methods and results: Sixty-two patients with VA (Non-MAE group) and 20 patients with VA complicated by MAE (MAE group) were enrolled in our Division of Cardiology between January 2010 and December 2015. Continuous variables were analyzed by t-test and categorical variables by Chi-square analysis. Patients with MAE showed greater QTc (corrected QT interval) dispersion (P = 0.005), Tp-ec (corrected Tp-e) interval (P = 0.001), Tp-ec dispersion (P < 0.001) and Tp-e/QT ratio (P < 0.001) than those in non-MAE groups when ST-segment elevated. After elevated ST-segment returned, there were no significant differences in these ECG parameters between two groups (All P > 0.05). At univariate binary logistic regression analysis QTc dispersion (odds ratio(OR) = 1.133; P = 0.013), Tp-ec (OR = 1.058; P = 0.003), Tp-e/QT (OR = 1.403; P = 0.001), and Tp-ec dispersion (OR = 1.497; P = 0.004) were significantly associated with MAE. At multivariable logistic regression analysis, Tp-ec dispersion remained a predictor of MAE. Receiver operating characteristic (ROC) curve analysis showed that only AUC (Area under curve) of Tp-ec dispersion had significant difference with those in QTc dispersion (P < 0.001), Tp-ec (P = 0.003), and Tp-e/QT ratio (P = 0.012), respectively. Conclusions: QTc dispersion, Tp-ec, Tp-e/QT and Tp-ec dispersion were significantly increased in VA patients with MAE than those without MAE when coronary spasm was onset. Prolonged Tp-ec dispersion was the best discriminators and a strong independent predictor of MAE in VA patients. (C) 2017 Published by Elsevier Ireland Ltd.