Background: An early repolarization pattern, characterized by an elevation of the QRS-ST junction (J-point) on 12-lead electrocardiography (ECG) is associated with cardiac and sudden death. However, little is known about the prognostic significance of J-point elevation for various disease-specific cardiovascular outcomes, including coronary artery disease (CAD).
Methods and results: To investigate the association between the presence of J-point elevation≥0.1 mV and various disease-specific cardiovascular outcomes, we conducted a 15-year prospective study in a representative general Japanese population of 7,630 individuals (41% men, mean age 52.4 years) who participated in the National Survey of Circulatory Disorders. Cox models were used to estimate the hazard ratios (HRs) adjusted for possible confounding factors. J-point elevation was present in 264 individuals (3.5%) and was associated with an increased risk of cardiac death (adjusted HR, 2.54; 95% confidence interval [CI] 1.40-4.58; P=0.002) and death from CAD (adjusted HR, 4.66; 95% CI 2.30-9.46; P<0.001). In a subgroup analysis by age, the association between J-point elevation and cardiovascular outcomes was more remarkable in middle-aged (<60 years) than in older individuals (≥60 years) (all P for interaction<0.05).
Conclusions: J-point elevation on standard 12-lead ECG was an independent predictor of cardiac death and death from CAD in a representative sample of the general Japanese population, particularly among the middle-aged.