Distribution and declines in cardiac allograft radionuclide left ventricular ejection fractions in relation to late mortality

Background: Cardiac allograft left ventricular ejection fraction (LVEF) is an important measure of left ventricular systolic function. Despite widespr ead use of LVEF after transplantation, its normal range and prognostic valu e in cardiac allografts has not been defined. Methods: We conducted a retrospective cohort study among 292 consecutive ad ult heart transplant patients. Left ventricular ejection fractions were per formed at 1, 3, 12, 24, and 48 months after transplantation using radionucl ide ventriculography. Endomyocardial biopsies assessed rejection, right hea rt catheterization assessed loading conditions, and angiography assessed al lograft 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 greater than or equal to4 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 remai ned stable afterward. These changes were not associated with concurrent cha nges in loading conditions, episodes of rejection, or development of allogr aft 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 reject ion episodes. Conclusions: The cardiac-allograft LVEF frequently decreases in the first y ear after transplantation. The 95th percentile of allograft LVEF value (<40 %) at Year 1 predicts late cardiac mortality among transplant recipients.