The QTc interval and risk of cardiac events in bulimia nervosa: A long‐term follow‐up study

OBJECTIVE: An association between bulimia nervosa (BN) and prolonged corrected QT interval (QTc) in the electrocardiogram has been suggested, but results of previous studies are conflicting, and the risk of cardiac events in patients with BN has yet to be investigated. METHOD: We estimated mean QTc interval and relative risk of borderline (QTc >440 ms) and prolonged QTc (QTc >460 ms) between adult women with BN (N = 531) and healthy controls (N = 123). In follow-up analyses, we investigated the risk of a primary endpoint (syncope, ventricular tachycardia, and cardiac arrest) and all-cause mortality in patients with BN (N = 702) compared with a population-based cohort derived from the Danish Civil Register (N = 7,020). RESULTS: Mean QTc did not differ between patients with BN and controls. Relative risk of borderline prolonged QTc was 2.3 (p = 0.28). The number of patients and controls with prolonged QTc was small, and the risk did not differ between patients with BN and controls. Median follow-up was 10.6 years. Although there appeared to be increased risks after 5 years of follow-up, long-term risks of the primary endpoint (Hazard ratio [HR] = 1.4, p = 0.37) and all-cause mortality (HR = 1.7, p = .28), respectively, were not increased in patients with BN compared to a population-based cohort. DISCUSSION: Mean QTc did not differ between patients with BN and healthy controls, and the risk of prolonged QTc was not increased in patients with BN. There was no difference in the long-term risk of cardiac events, and long-term all-cause mortality did not differ significantly between patients with BN and a population-based cohort.