Abstract 2577: N-Terminal Pro-BNP Predicts Severe Late Rejection in Heart Transplant Recipients
Purpose: N-terminal Pro-Brain Natriuretic Peptide (NT pro-BNP) is of great value for detection of ventricular dysfunction and may be used as a screening technique for heart failure. Acute rejection is a common problem after heart transplantation (HTX) and the gold standard for this diagnosis is still the endomyocardial biopsy. Data on the use of NT pro-BNP early post-HTX for diagnosis of rejection seems promising, but data on the diagnosis of late rejection are not known. The aim of this study was to determine the predictive value of NT pro-BNP to diagnose rejection in HTX pts late after transplantation (>6 months).
Methods: We measured NT pro-BNP levels during biopsy procedures in patients late after HTx. The level of NT pro-BNP was compared with the degree of rejection as determined by histological grading of the biopsies using the ISHLT grading system. Rejection was defined as grade 3A or more. We used the ROC curve to determine the highest sum of specificity en sensitivity to detect a cut-off value of NT Pro-BNP for predicting late rejection. Differences between patient groups were evaluated by using Student’s T-test.
Results: We evaluated 27 pts (7 rejectors and 20 nonrejectors)) with a mean age of 49 yrs (18 – 65 yrs). Median time after transplantation was 14 months [range 7–140]. NT Pro-BNP was significantly higher (p=0.004) in patients with rejection compared to patients without rejection: 460 ± 540 pmol/l [range 34 to 1500 pmol/l] vs. 45 ± 27 pmol/l [range 10 to 125 pmol/l]. The cut-off value of NT Pro-BNP for clinical significant late rejection (> grade 3A) was 63 pmol/l with a sensitivity and specificity of 86 and 94 % respectively.
Conclusion: Present data shows that late rejection is often associated with significantly higher NT Pro-BNP levels, with a cut-of value of 63 pmol/l. Measurement of NT Pro-BNP may become a useful marker for non-invasive diagnosis of rejection, being most valuable in the exclusion of allograft rejection necessating additional therapy