Early repolarization is associated with a significantly increased risk of ventricular arrhythmias and sudden cardiac death in patients with structural heart diseases

Abstract

Background: Early repolarization pattern (ERP) has been proved to increase risk of arrhythmia death in the general population, but its prognostic significance in patients with structural heart disease (SHD) is controversial.

Objective: The purpose of this study was to conduct a meta-analysis of studies assessing the association between ERP and risk of ventricular arrhythmias (VTAs) and sudden cardiac death (SCD) in patients with SHD.

Methods: We performed a literature search using MEDLINE (January 1, 1966, to September 25, 2016) and EMBASE (January 1, 1980, to September 25, 2016) with no restrictions. Studies that reported odds ratio (OR) estimates with 95% confidence intervals (CIs) for the associations of interest were included.

Results: The search yielded 19 observational studies, involving 7268 patients that reported 1127 cases of VTAs or SCD. In the selected studies, the point estimates of the ORs were consistently greater than 1. Compared with those without ERP, patients with ERP experienced a significantly increased risk of developing VTAs or SCD (OR 4.76; 95% CI 3.62-6.26), ventricular fibrillation (OR 7.14; 95% CI 4.31-11.82), and SCD (OR 4.07; 95% CI 1.58-10.51). The results were consistent and statistically significant in all subgroups. ERP with J-point elevation in inferior leads, notching configuration, and horizontal or descending ST segment connote higher risk.

Conclusion: ERP is associated with a significant increased risk of VTAs or SCD in patients with SHD. Future research should attempt to understand the exact mechanisms for the arrhythmia risk and to introduce ERP in the risk stratification in this patient group.

Keywords: Early repolarization pattern; Structural heart disease; Sudden cardiac death; Ventricular fibrillation; Ventricular tachycardia.