Abstract 12085: B-type Natriuretic Peptide Behavior After Pediatric Heart Transplantation: Impact of Ischemic Time
Background: Whole blood B-type natriuretic peptide concentrations (BNP) are increasingly utilized in the management of pediatric heart transplant (HT) recipients but factors affecting their variation remain uncertain. We hypothesized variables at time of transplant would affect BNP levels within the first 12 months after HT.
Methods: We performed a prospective observational study measuring BNP within the routine surveillance protocol of 50 HT recipients (age 0.1 to 21yr, median of 9.5yr [IQR 0.9-14yr]) 1 to 57 weeks after HT. BNP was also measured as part of diagnosis and treatment of rejection.
Results: BNP decreased exponentially from a median of 451 pg/ml [IQR 245-1206] 2 weeks post-HT and plateaued (Figure) 110-120 days post HT (median 61pg/mL [IQR 27- 100]). Significant variables determining plateau BNP 120 days post-HT included: infants (< 1 year of age at HT) (median 103 pg/mL [IQR 62-199 pg/mL]; p=0.002]; cold ischemic time (CIT) greater than 190 minutes (median, 96 pg/mL [IQR 46-138 pg/mL]]; p=0.01); and warm ischemic time (WIT) greater than 70 minutes (median, 90 pg/mL [IQR 66-131 pg/mL]). Correlation of left ventricle fractional shortening to BNP plateau levels was not significant (r=-0.088, p=0.397) and was modest-poor between BNP and right atrial pressure (r=0.4652, p< 0.0001) and pulmonary capillary wedge pressures (r=0.2660, p<0.0011). No change in BNP were observed coincident with rejection except in 1 episode with clinically severe hemodynamic compromise.
Conclusion: This pilot study suggests BNP levels in the first 12 months after HT have a substantial decline and then plateau approximately 4 months after pediatric HT. Final plateau levels are affected by age, CIT, and WIT. This phenomenon limits use in the first months after HT and suggests long-term effects of CIT and WIT on allograft function. BNP levels do not appear to fluctuate in rejection without hemodynamic compromise.
- © 2012 by American Heart Association, Inc.