Predictors of Kidney Dysfunction in Heart Transplant Recipients

Cardiovascular disease and kidney disease seem to be lethally synergistic, both approaching the level of epidemics. Patients with cardiovascular disease often have impaired kidney function; on the other hand, cardiovascular disease is the single best predictor of mortality among patients with chronic kidney disease. The risk in a patient with moderately impaired renal function is comparable in magnitude to that of a patient with diabetes mellitus.The aim of this study was to assess risk factors for kidney dysfunction among 162 prevalent heart transplant (OHT) recipients (127 males and 22 females). Stages of chronic kidney disease were defined according to Kidney Disease Outcomes Quality Initiative guidelines using the estimated glomerular filtration rate (GFR). Mean serum creatinine in this population was 1.70 ± 1.08 mg/dL (range, 0.54–9.34). The mean age was 54 ± 14 years and the average time after transplantation was 106 ± 52 months (range, 10–210). Mean GFR was 62.92 ± 31.04 mL/min (Cockcroft-Gault formula), 55.38 ± 26.74 mL/min (MDRD), and 62.62 ± 35.61 mL/min (creatinine clearance). Estimated GFR, creatinine clearance, and serum creatinine correlated upon univariate analysis with hemoglobin, red blood cell count, age, time after transplantation, ejection fraction, N-terminal prohormone brain natriuretic peptide, and use of calcineurin inhibitors. Upon multiple regression analysis predictors of kidney function (GFR) were age (beta value, −0.47; P < .001), time after transplantation (beta value, −0.22; P = .03), and hemoglobin (beta value, 0.31; P = .03), explaining 51% of the variation among GFR values in this group. When GFR was substituted with creatinine clearance, the results were similar. Among heart transplant recipients, kidney function was predominantly dependent on age and time after transplantation (both nonmodifiable causes), as well as anemia (which may be modified).