BNP, hemodynamics and biopsies were obtained for 205 transplant recipients who underwent a total of 4,007 endomyocardial biopsy procedures. Samples analyzed were collected 鈮?80 days post-transplant, without evidence of rejection on the immediately preceding biopsy. Using a repeated-measures multivariate model, we assessed the association of change in BNP with Grade 鈮?A (2R) rejection. We also determined predictive values of various cut-off thresholds of change in serial BNP levels to predict Grade 鈮?A rejection.
There were 47 episodes of Grade 鈮?A rejection among the 1,350 samples analyzed. Median change in serial BNP (螖BNP) for those with Grade 鈮?A rejection was 20 pg/ml (IQR 鈭?6 to 169 pg/ml) and among those with Grade <3A rejection was 鈭? pg/ml (IQR 鈭?4 to 22 pg/ml, p = 0.003). On multivariate analysis, 螖BNP remained the most potent independent predictor of Grade 鈮?A rejection (p = 0.001). 螖BNP >100 pg/ml predicted increased risk of Grade 鈮?A rejection (OR = 5.3, p < 0.001) with high specificity (93.3%) and positive predictive value (13.0%) and excellent negative predictive value (97.3%).
Change in serial BNP level is an independent predictor of cardiac allograft rejection. With wide availability, rapid turnaround, low cost, favorable positive predictive value and excellent negative predictive value, serial BNP monitoring has several advantages for non-invasive monitoring of heart transplant recipients for acute cardiac allograft rejection.