Taking QT-prolonging medications in the past month was associated with more than a twofold increase in the odds of a prolonged QTc interval in both men and women.
Cross-Sectional (n=8,561)
Yes
What are the risk factors for prolonged QTc interval in US adults over 40 years of age?
Age, female sex, specific electrolyte abnormalities, history of thyroid disease or myocardial infarction, and recent use of QT-prolonging drugs are independent risk factors for prolonged QTc in the general US adult population.
Effect estimate: OR >2
BACKGROUND: QT interval prolongation can lead to torsades de pointes, a potentially fatal arrhythmia. Although research exists on the relationship between QT prolongation and clinical outcome, few studies have described risk factors for prolonged QT interval in the general population. METHODS: The Third National Health and Nutrition Examination Survey (NHANES III) collected electrocardiogram interval data on 8561 subjects over 40 years of age and projected results to the US population. QT was corrected for heart rate using Fridericia's formula. Logistic regression analyses were performed to identify factors independently associated with prolonged QTc interval, defined as being in the upper 5% of the population QTc interval distribution. Analyses were conducted separately for women and men as a result of differences in the QT distribution between the sexes and also because of potential effect modification. Analytical variables included age, race/ethnicity, electrolyte measurements, body mass index, the recent use of QT-prolonging drugs and past medical histories of stroke, thyroid disease, hypertension, diabetes and myocardial infarction. RESULTS: Age, female sex, hypocalcemia (men), hypokalemia (women), and a history of thyroid disease and myocardial infarction (men) were associated with a prolonged QTc interval. In addition, taking QT-prolonging medications in the past month was associated with more than a twofold increase in the odds of prolonged QTc interval in both men and women. CONCLUSIONS: Healthcare practitioners should be aware that a prolonged QTc interval is a potential indicator of cardiovascular risk, and should exercise caution in prescribing potentially QT-prolonging medications to certain patients.
Benoit et al. (Mon,) conducted a cross-sectional in Prolonged QTc interval (n=8,561). QT-prolonging medications and clinical risk factors vs. Unexposed/reference groups was evaluated on Prolonged QTc interval (upper 5% of the population QTc interval distribution) (OR >2). Taking QT-prolonging medications in the past month was associated with more than a twofold increase in the odds of a prolonged QTc interval in both men and women.