Abstract 9890: First-Year Brain Natriuretic Peptide as a Biomarker after Heart Transplant Predicts Outcome and Severity of Cardiac Allograft Vasculopathy

Purpose: Brain natriuretic peptide (BNP) has been reported to be a biomarker for poor outcome after heart transplant. Elevated BNP levels have been associated with reduced survival and an increase in the development of cardiac allograft vasculopathy (CAV). It has not been established whether high levels of BNP at 1-year post-transplant also correlate with severity of cardiac allograft vasculopathy per the new ISHLT cardiac allograft vasculopathy nomenclature. Methods: We evaluated 238 patients who received a heart transplant between 2001-2007. Patients were separated into three groups based on BNP levels at the 1st-year: 157 patients with BNP <100 pg/mL, 56 patients with BNP 100-250 pg/mL, and 25 patients with BNP >250 pg/mL. Study patients were followed for 5 years for endpoints of survival, freedom from cardiac allograft vasculopathy (stenosis 30%), and freedom from non-fatal major adverse cardiac events (NF-MACE: MI, CHF, stroke, and need for angioplasty or pacemaker/ICD) and 1st-year freedom from any-treated rejection. Results: Patients with BNP >250 pg/mL at the 1st-year had significantly lower survival, freedom from NF-MACE, and freedom from cardiac allograft vasculopathy compared to the lower groups of BNP. Severity of cardiac allograft vasculopathy was higher in the BNP >250 group compared to the other two groups. Of those patients who developed cardiac allograft vasculopathy, the high BNP group had more patients who developed CAV2 or CAV3 compared to patients with BNP 100-250 and BNP <100 pg/mL (24% vs. 4% vs. 7%, respectively; p=0.01). The high BNP group also had less freedom from any-treated rejection than the other two groups. Conclusion: Elevated 1st-year levels of BNP >250 pg/mL appears to be a biomarker for poor outcome and the subsequent development of more severe cardiac allograft vasculopathy. Targeted change in immunosuppression such as switch to proliferation signal inhibitors might be considered for this high risk population.