Background and purpose: Currently, endomyocardial biopsy is the most reliable method to detect an acute rejection after heart transplantation. However, as an invasive procedure it is associated with a definite risk for complications. Therefore, it was examined whether changes in QT time and QT dispersion on the surface ECG are able to predict an acute cellular rejection.
Patients and methods: During the first 3 months after heart transplantation, QT time, heart rate-corrected QT time (QTc time), QT dispersion, and heart rate-corrected QT dispersion (QTc dispersion) were analyzed in 100 patients with acute cellular rejection grade > or = II according to the International Society for Heart and Lung Transplantation (ZA group), and in 100 patients without or with only mild rejection episodes (< or = grade I; MA group). Results were obtained by determining the difference in the ZA group between the QT interval in the presence of a rejection and the QT interval at other time points, which were then compared with the results of the MA group at matched time points.
Results: At the time point of rejection, the ZA group showed a mean prolongation in both QTc time and QTc dispersion of > 40 ms compared with other time points. Such differences were not seen in the MA group (p < 0.001 for comparisons between study groups). If prolongations in QTc time and QTc dispersion of > 25 ms were used as predictors for an acute rejection, sensitivity was 77% and 70%, respectively, and specificity was 96% and 95%, respectively.
Conclusion: Provided that ECGs are performed regularly, measurements of QTc time and QTc dispersion can reliably be used to detect an acute rejection in the early phase after heart transplantation.