Early Repolarization Pattern and Risk for Arrhythmia Death : A Meta-Analysis

ObjectivesA meta-analysis was performed to determine the risk and incidence rate of arrhythmia death, cardiac death, and all-cause death in the general population with the early repolarization pattern (ERP).BackgroundThe ERP has recently been associated with vulnerability to ventricular fibrillation in case-control studies. However, the prognostic significance of the ERP in the general population is controversial.MethodsRelevant studies published through July 31, 2012, were searched and identified in the MEDLINE and Embase databases. Studies that reported risk ratio estimates with 95% confidence intervals (CIs) for the associations of interest were included. Data were extracted, and summary estimates of association were obtained using a random-effects model.ResultsOf the 9 studies included, 3 studies reported on arrhythmia death (31,981 subjects, 1,108 incident cases during 726,741 person-years of follow-up), 6 studies reported on cardiac death (126,583 subjects, 10,010 incident cases during 2,054,674 person-years of follow-up), and 6 studies reported on all-cause death (112,443 subjects, 22,165 incident cases during 2,089,535 person-years of follow-up). The risk ratios of the ERP were 1.70 (95% CI: 1.19 to 2.42; p = 0.003) for arrhythmia death, 0.78 (95% CI: 0.27 to 2.25; p = 0.63) for cardiac death, and 1.06 (95% CI: 0.87 to 1.28; p = 0.57) for all-cause death. The estimated absolute risk differences of subjects with the ERP were 70 cases of arrhythmia death per 100,000 subjects per year. J-point elevation ≥ 0.1 mV in the inferior leads and notching configuration had an increased risk for arrhythmia death in subgroup studies.ConclusionsThe ERP was associated with increased risk and a low to intermediate absolute incidence rate of arrhythmia death. Further study is needed to clarify which subgroups of subjects with the ERP are at higher risk for arrhythmia death.