title: Prolonged corrected QT interval is predictive of future stroke events even in subjects without ECG-diagnosed left ventricular hypertrophy.
abstract: We attempted to evaluate whether subjects who exhibit prolonged corrected QT (QTc) interval (≥440 ms in men and ≥460 ms in women) on ECG, with and without ECG-diagnosed left ventricular hypertrophy (ECG-LVH; Cornell product, ≥244 mV×ms), are at increased risk of stroke. Among the 10 643 subjects, there were a total of 375 stroke events during the follow-up period (128.7±28.1 months; 114 142 person-years). The subjects with prolonged QTc interval (hazard ratio, 2.13; 95% confidence interval, 1.22-3.73) had an increased risk of stroke even after adjustment for ECG-LVH (hazard ratio, 1.71; 95% confidence interval, 1.22-2.40). When we stratified the subjects into those with neither a prolonged QTc interval nor ECG-LVH, those with a prolonged QTc interval but without ECG-LVH, and those with ECG-LVH, multivariate-adjusted Cox proportional hazards analysis demonstrated that the subjects with prolonged QTc intervals but not ECG-LVH (1.2% of all subjects; incidence, 10.7%; hazard ratio, 2.70, 95% confidence interval, 1.48-4.94) and those with ECG-LVH (incidence, 7.9%; hazard ratio, 1.83; 95% confidence interval, 1.31-2.57) had an increased risk of stroke events, compared with those with neither a prolonged QTc interval nor ECG-LVH. In conclusion, prolonged QTc interval was associated with stroke risk even among patients without ECG-LVH in the general population.
authors.affiliation: From the Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan (J.I., K.K.); and Division of Community and Family Medicine, Center for Community Medicine, Jichi Medical University, Shimotsuke, Japan (S.I.). george@jichi.ac.jp.
authors.forename: Joji
authors.initials: J
authors.lastname: Ishikawa
authors.affiliation: From the Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan (J.I., K.K.); and Division of Community and Family Medicine, Center for Community Medicine, Jichi Medical University, Shimotsuke, Japan (S.I.).
authors.forename: Shizukiyo
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: From the Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan (J.I., K.K.); and Division of Community and Family Medicine, Center for Community Medicine, Jichi Medical University, Shimotsuke, Japan (S.I.).
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Kario
mesh_terms: D000328:Adult; D000368:Aged; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications* / Q000503:physiopathology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D012737:Sex Factors; D020521:Stroke / Q000453:epidemiology* / Q000503:physiopathology*
keywords: electrocardiography; epidemiology; hypertrophy, left ventricular; stroke