Long-term evolution, secular trends, and risk factors of renal dysfunction following cardiac transplantation

Abstract

Recent reports suggest that individuals who underwent heart transplantation in the last decade have improved post-transplant kidney function. The objectives of this retrospective study were to describe the incidence and to identify fixed and time-dependent predictors of renal dysfunction in cardiac recipients transplanted over a 25-year period (1983-2008). To illustrate temporal trends, patients (n=306) were divided into five groups based on year of transplantation. The primary endpoint was the estimated glomerular filtration rate (eGFR) at year 1. Secondary endpoints were time to moderate (eGFR <60ml/min/1.73m(2) ) and severe renal dysfunction (eGFR <30ml/min/1.73m(2) ). Risk factor analyses relied on multivariable regression models. Kidney function was mildly impaired before transplant (median eGFR=61.0ml/min/1.73m(2) ), improved at discharge (eGFR=72.3 ml/min/1.73m(2) ; P<0.001), decreased considerably in the first year (eGFR=54.7 ml/min/1.73m(2) ; P<0.001), and deteriorated less rapidly thereafter. At year 1, 2004-2008 recipients exhibited a higher eGFR compared with all other patients (P<0.001). Factors independently associated with eGFR at year 1 and with moderate and severe renal dysfunction included age, gender, pretransplant eGFR, blood pressure, glycemia, and use of prednisone (P<0.05). In summary, kidney function worsens constantly up to two decades after cardiac transplantation, with the greatest decline occurring in the first year. Corticosteroid minimization and treatment of modifiable risk factors (hypertension, diabetes) may minimize renal deterioration.