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 +/- 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 >or=10% between the first and second post-transplantation year (DeltaQTc >or= 10%) had a 6.86-times higher risk of dying compared with patients with DeltaQTc < 10% (p = 0.0005). Furthermore, DeltaQTc >or= 10% was the only independent predictor of long-term mortality on multivariate analysis (p = 0.0008).


CONCLUSIONS
A relative increase in QTc interval duration of >or=10% between the first and second post-transplantation year is a strong, independent predictor of mortality in heart transplant recipients.
Vrtovec
Bojan
B
Department of Cardiopulmonary Transplantation, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77225-0345, USA.
Radovancevic
Rajko
R
Thomas
Cynthia D
CD
Yazdabakhsh
Aria P
AP
Smart
Frank W
FW
Radovancevic
Branislav
B
D000328:Adult; D016757:Death, Sudden, Cardiac; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000601:surgery; D016027:Heart Transplantation; D006801:Humans; D008133:Long QT Syndrome; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors