The QT Interval Is Associated With Incident Cardiovascular Eventse The MESA Study

BACKGROUND Prolonged heart rate-corrected QT interval on electrocardiograms (ECGs) is associated with increased risk of myocardial infarction and cardiovascular disease (CVD)-related deaths in patients with prevalent coronary heart disease. OBJECTIVES This study sought to examine the prognostic association between the baseline QT interval and incident cardiovascular events in individuals without prior known CVD. METHODS The corrected baseline 12-lead ECG QT interval duration (QT(corr)) was determined by adjustment for age, sex, race/ethnicity, and RR interval duration in 6,273 participants in MESA (Multi-Ethnic Study of Atherosclerosis). Cox proportional hazards models adjusting for demographic and clinical risk factors were used to examine the association of baseline QTcorr with incident cardiovascular events. RESULTS The mean age at enrollment was 61.7 +/- 10 years, and 53.4% of participants were women. Cardiovascular events occurred in 291 participants over a mean follow-up of 8.0 +/- 1.7 years. Each 10-ms increase in the baseline QT(corr) was associated with incident heart failure (hazard ratio [HR]: 1.25; 95% CI: 1.14 to 1.37), CVD events (HR: 1.12; 95% CI: 1.05 to 1.20), and stroke (HR: 1.19; 95% CI: 1.07 to 1.32) after adjustment for CVD risk factors and potential confounders. There was no evidence of interaction with sex or ethnicity. CONCLUSIONS The QT interval was associated with incident cardiovascular events in middle-aged and older adults without prior CVD.