Do patients with long QT syndrome remain at risk for sudden cardiac death after 40 years of age?

Long QT syndrome (LQTS) is an inherited arrhythmic disorder in which patients display a propensity for prolongation of the heart rate-corrected QT interval (QTc) and for sudden cardiac death. To obtain a better understanding of this disease, the International LQTS Registry was initiated in 1979, and has been an invaluable source of data on patients aged 40 years and younger with LQTS. The registry collaborators have now described 2,759 LQTS patients and controls aged older than 40 years. In this age group, a prolonged QTc, syncope in the last 10 years, and LQTS-3 were found to be the most important predictors of death from any cause or cardiac arrest requiring defibrillation in patients with LQTS (hazard ratios 2.65-9.92). Clearly, patients with LQTS remain at increased risk of lethal events after 40 years of age, indicating that continuous, age-independent awareness for QT prolongation is essential.