Renal insufficiency and end-stage renal disease in the heart transplant population

Abstract

Background Renal insufficiency and end-stage renal disease (ESRD) are important problems in the cardiac transplant population, and are associated with significant morbidity, mortality and financial cost. We undertook this study to define pre-operative or early post-operative predictors of subsequent renal insufficiency and ESRD. Methods We studied 370 patients at Brigham and Women's Hospital who received heart transplants between 1984 and 1999, with up to 10-year follow-up. We evaluated 2 time-dependent primary outcomes: early reduction in GFR, and development of ESRD at any timepoint. Cox proportional hazards modeling was used in both univariate and multivariate analyses. Results The mean estimated glomerular filtration rate (GFR) fell 24% within the first post-transplant year, and remained stable thereafter. By actuarial analysis, 23% of patients developed a 50% reduction in GFR by the third year, and 20% developed ESRD by the tenth year of follow-up. In Cox multivariate analysis, significant predictors of post-transplant ESRD included: GFR <50ml/min (hazards ratio [HR] 3.69, p = 0.024); high mean cyclosporine trough in the first 6 months (HR 5.10, p = 0.0059); and presence of diabetes (HR 3.53, p = 0.021). Conclusions about renal insufficiency outcome were limited by difficulties with accurate estimation of GFR and with definition of renal insufficiency. Conclusions The results of this study underscore the magnitude of the problem of renal insufficiency and ESRD in the heart transplant population. In addition, these data suggest that patients at high risk for these outcomes can be identified early, even pre-operatively, to guide post-operative management.