Impact of age and sex on the long-term prognosis associated with early repolarization in the general population

Abstract

Early repolarization (ER) has been linked to the risk of sudden cardiac death (SCD) in the general population, although controversy remains regarding risks across various subgroups. The purpose of this study was to investigate whether age and sex influence the prognostic significance of ER. We evaluated the 12-lead electrocardiograms of 6631 Finnish general population subjects age ≥30 years (mean age 50.1 ± 13.9 years; 44.5% men) for the presence of ER (J-point elevation ≥0.1 mV in ≥2 inferior/lateral leads) and followed them for 24.4 ± 10.3 years. We analyzed the association between ER and the risk of SCD, cardiac death, and all-cause mortality in subgroups according to age (<50 or ≥50 years) and sex. ER was present in 367 of the 3305 subjects age <50 years and in 426 of 3326 subjects ≥50 years. ER was not associated with any of the endpoints in the entire study population. After adjusting for clinical factors, ER was associated with SCD (hazard ratio [HR] 1.88; 95% confidence interval [CI] 1.16-3.07) in subjects <50 but not in older subjects (interaction between ER and age group, P = .048). In the younger subgroup, women with ER had a high risk of SCD (HR 4.11; 95% CI 1.41-12.03), whereas among men ER was not associated with SCD. Finally, ER was not associated with cardiac mortality or all-cause mortality in either age group. ER is associated with SCD in subjects younger than 50 years, particularly in women, but not in subjects 50 years and older.