The QT interval is associated with incident cardiovascular events: 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, ⁹ 273 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 QT_corr 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.