Background: Cardiac allograft left ventricular ejection fraction (LVEF) is an important measure of left ventricular systolic function. Despite widespread use of LVEF after transplantation, its normal range and prognostic value in cardiac allografts has not been defined.
Methods: We conducted a retrospective cohort study among 292 consecutive adult heart transplant patients. Left ventricular ejection fractions were performed at 1, 3, 12, 24, and 48 months after transplantation using radionuclide ventriculography. Endomyocardial biopsies assessed rejection, right heart catheterization assessed loading conditions, and angiography assessed allograft coronary artery disease. We used Cox proportional hazards model to examine the predictive value of LVEF on late mortality.
Results: Of the patients who survived > or =4 years, the mean allograft LVEF decreased 4.7 units at 3 months, from 63.8 to 59.7; an additional 4.1 units at 12 months, from 59.7 to 55.6 (p < 0.001); and remained stable afterward. These changes were not associated with concurrent changes in loading conditions, episodes of rejection, or development of allograft coronary artery disease. Left ventricular ejection fraction lower than the 95% normal limit (<40%) at 12 months was inversely associated with risk for late cardiac mortality (relative risk = 3.5, 95% confidence interval = 1.0-12.2), while controlling for recipient age, sex, donor age, and rejection episodes.
Conclusions: The cardiac-allograft LVEF frequently decreases in the first year after transplantation. The 95th percentile of allograft LVEF value (<40%) at Year 1 predicts late cardiac mortality among transplant recipients.