Prognostic value of the QTc interval after cardiac transplantation

Background: Although QTc interval prolongation is considered a risk factor for adverse outcome in the non-transplant population, its predictive value in heart transplant recipients has not been studied yet. This study was conducted to determine whether prolonged QTc interval is a useful predictor of outcome in heart transplant recipients. Methods: QTc intervals were measured in 587 adult patients who underwent heart transplantation between May 1982 and January 2002. QT interval duration was. determined by averaging 3 consecutive beats in all 12 leads of the standard electrocardiogram (ECG) and corrected with the Bazett formula. Baseline ECGs were obtained within 7 days after transplantation; follow-up ECGs were'recorded annually at the time of routine angiography. Patients were followed over 85 t 65 months (range, 3 months-17 years). Results: During follow-up, 241 patients died. The mean QTc interval duration in these patients was comparable with that in the remaining cohort (432 +/- 26 msec vs 423 +/- 25 msec, p = 0.07). However, patients with a relative increase in QTc duration of >= 10% between the first and second post-transplantation year,(Delta QTc >= 10%) had a 6.86-times higher risk of dying compared with patients with Delta QTc < 10% (p = 0.0005). Furthermore, Delta QTc >= 10% was the only independent predictor of long-term mortalityon multivariate analysis (p = 0.0008). Conclusions: A relative increase in QTc interval duration of >= 10% between the first and second post-transplantation year is a strong, independent predictor of mortality in. heart transplant recipients. J Heart Lung Transplant 2006;25:29-35. Copyright (c) 2006 by the International Society for Heart and Lung Transplantation.