Meta-analysis of Tpeak–Tend and Tpeak–Tend/QT ratio for risk stratification in congenital long QT syndrome

Abstract

Background and objectivesCongenital long QT syndrome (LQTS) predisposes affected individuals to ventricular tachycardia/fibrillation (VF/VF), potentially resulting in sudden cardiac death. The Tpeak–Tend interval and the Tpeak–Tend/QT ratio, electrocardiographic markers of dispersion of ventricular repolarization, were proposed for risk stratification but their predictive values in LQTS have been controversial. A systematic review and meta-analysis was conducted to examine the value of Tpeak–Tend intervals and Tpeak–Tend/QT ratios in predicting arrhythmic and mortality outcomes in congenital LQTS. MethodPubMed and Embase databases were searched until 9th May 2017, identifying 199 studies. ResultsFive studies on long QT syndrome were included in the final meta-analysis. Tpeak–Tend intervals were longer (mean difference [MD]: 13ms, standard error [SE]: 4ms, P=0.002; I2=34%) in congenital LQTS patients with adverse events [syncope, ventricular arrhythmias or sudden cardiac death] compared to LQTS patients without such events. By contrast, Tpeak–Tend/QT ratios were not significantly different between the two groups (MD: 0.02, SE: 0.02, P=0.26; I2=0%). ConclusionThis meta-analysis showed that Tpeak–Tend interval is significant higher in individuals who are at elevated risk of adverse events in congenital LQTS, offering incremental value for risk stratification.