N-Terminal Pro–B-Type Natriuretic Peptide (NT-proBNP) Assessment in the First Year After Renal Transplantation and Its Relationship With Graft Function and Left Ventricular Hypertrophy

Abstract

BackgroundNT-proBNP is a natriuretic neurohormone released mainly from ventricular cardiomyocytes in conditions of volumetric or pressure overload; it is suitable for use as a marker of left ventricular hypertrophy (LVH), a common disorder in renal transplant recipients. The study objective here was to assess NT-proBNP levels in the 1st year after renal transplantation (RT) and its relationship with graft function and LVH. MethodsSixty patients (age, 49 ± 16.9 y; male, 58%) were subjected to prospective 1-year follow-up. Basic blood tests and NT-proBNP level measurements were performed twice (in the early period and at 1 year after transplantation). Cardiac echography was performed in 40 patients. LVH was diagnosed when left ventricular mass index was >95 g/m2 in women and >115 g/m2 in men. Statistical analyses were performed with the use of the R Package. ResultsAt 1 year after RT, the NT-proBNP level decreased >2-fold compared with the early period (median 171 pg/mL [interquartile range (IQR), 104.5–283] vs 368 pg/mL[IQR, 170–629]; P = .00008). In the early post-transplantation period, NT-proBNP correlated with the patient's age, body mass index, estimated glomerular filtration rate (eGFR), and left ventricular end-diastolic dimension, and at 1 year after transplantation its correlation with the eGFR range (patients with eGFR ≥60 mL min−1 1.73 m−2 had significantly lower NT-proBNP levels than those with eGFR <60 mL min−1 1.73 m−2), with age,and with ejection fraction was found. Patients with LVH had higher NT-proBNP levels than those without LVH in the early period (median 511 pg/mL [IQR, 190–736] vs 380 pg/mL [IQR, 217–511]; P = .09), and at 1 year (median 269 pg/mL [IQR, 155–474] vs 133 pg/mL [IQR, 99–134]; P = .057). At NT-proBNP >480 pg/mL in the early period and >280 pg/mL at 1 year, LVH occurred with a 68% probability (P = .05 and P = .03, respectively). ConclusionsDuring the 1st year after RT, NT-proBNP levels decrease ≥2-fold and are primarily related to eGFR. NT-proBNP measurements are useful in identifying patients with LVH.