Serum creatinine and estimated glomerular filtration rate (eGFR) (24 hours creatinine clearance, Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration, Cockcroft-Gault formulae), and urinary kidney injury molecule-1 (KIM-1), were evaluated in 111 heart allograft recipients on therapy with a calcineurin inhibitor, mycophenolate mofetil or azathioprine plus prednisone. KIM-1 was assessed using commercially available assay. Normotensive heart allograft recipients showed significantly lower KIM-1 values than hypertensive subjects. Urinary KIM-1 was significantly higher among New York Heart Association class III versus I and II patients. Upon univariate analysis, urinary KIM-1 strongly correlated with serum creatinine (r = .54) and eGFR (r = .66) but only weakly with other parameters. It was not related to cystatin C. Upon multiple regression analysis, the best predictor of urinary KIM-1 was eGFR (beta −0.56), explaining 76% of KIM-1 concentrations. Even a successful heart transplantation is associated with kidney injury as reflected by elevated urinary KIM-1 and reduced eGFR. Therefore, KIM-1 needs to be investigated as a potential early marker for impaired kidney function/kidney injury, especially in patients with other risk factor for kidney damage, for example, hypertension or congestive heart failure.
