Abstract 3121: Serum BNP Response To Pulmonary Vasodilator Therapy In Eisenmenger’s Syndrome
Hypothesis: Pulmonary arterial vasodilator therapy (Rx) decreases BNP levels and improves functional capacity in Eisenmenger’s syndrome.
Methods: Retrospective single center registry. Paired T-test used for parametric variables and Wilcoxon Signed Rank test used for non-parametric variables.
Results: Eighteen patients (14 females), mean age 38 years (range 26 to 59) with ES and BNP levels pre and on Rx were included. Diagnoses included: VSD (n=6), truncus arteriosus (n=3), ASD (n=2), single ventricle (n=2), AV canal (n=3), PDA (n=1), and total anomalous pulmonary venous return (n=1). Oral Rx consisted of: Bosentan (n=10), sildenafil (n=5), or both (n=3). Seven patients also received diuretic therapy. BNP was rechecked a mean of 7.5 months (range 1 to 23) on Rx. BNP levels declined a mean of 288 pg/ml (477 to 189 pg/ml, p=0.04), 6 minute walk distance increased a mean of 35 meters (238 to 273 meters, p=0.05), and resting oxygen saturation increased from 75% to 80% (+5%, p=0.036). In patients treated with bosentan, pre-treatment mean BNP was 178 pg/ml and declined by 82 pg/ml on Rx. Patients treated with sildenafil had a higher baseline BNP (1165 pg/ml) that declined a mean of 772 pg/ml on therapy. Four of the five pts treated with sildenafil also received diuretic therapy. Two patients died during the treatment period, a 59 year old female with ASD and a 32 year old female with Down syndrome and VSD. Both died of CHF complications 1 and 2 months after initiating Rx with sildenafil, respectively. These 2 patients had the highest BNP levels of the cohort and were the only two that failed to demonstrate a decline in BNP to below 500 pg/ml on Rx. Both sildenafil and bosentan were well tolerated.
Conclusions: Oral pulmonary vasodilator therapy results in decreased BNP levels, increased 6 MWD, and increased oxygen saturation. Both sildenafil and bosentan lower BNP, however, sildenafil was preferentially used in patients with signs of volume overload and higher BNP levels. Persistent highly elevated BNP levels (>500 pg/ml) on therapy may identify patients at highest risk of death from heart failure.