Author + information
- Jamil A. Aboulhosn,
- Gwendolyn Derk,
- Linda Houser,
- Pamela Miner,
- Ryan Williams,
- John Moriarty,
- Juan Alejos and
- Paul Finn
Patients with single ventricle physiology typically undergo multiple surgical palliations culminating in the Fontan operation. The efficient function of the Fontan is dependent on numerous factors, including the presence of a low pulmonary vascular resistance. Phosphodiesterase 5 inhibitors have recently been shown to improve cardiac output and functional capacity by lowering vascular resistance. We sought to test the efficacy and safety of endothelin blockade with Bosentan in a cohort of adult patients with Fontan physiology.
Seven adult Fontan patients completed this single center open label clinical trial. Patients were treated with Bosentan for 4 months. Cardiac MRI, six minute walking distance (6MWD), brain natriuretic peptide (BNP), and NYHA functional class were compared before and after treatment using paired T-test.
6MWD improved by 73 meters, from a mean of 435 meters (SD=92, SE 35) to 508 meters (SD=93, SE=35) (p=0.03). MRI resting aortic flow increased from 3.3 l/min (SD=1.27, SE=0.73) to 4.4 l/min (SD=0.9, SE=0.54) (p=0.03). NYHA class improved in 3 patients and worsened in 1 patient. BNP, AST, and ALT did not change significantly. Of three patients with elevated baseline bilirubin, 2 had normalized at the completion of the study, the other was unchanged. Mean duration of therapy was 4.1 ± 0.51 months. There were no deaths or hospitalizations. Two adverse advents occurred. One patient complained of fatigue and chest pain after 87 days and withdrew from the study. After extensive work-up, it was determined that her symptoms were not related to treatment. The second patient suffered palpitations and fatigue after 75 days of treatment, no concerning arrhythmias were identified but symptoms improved with increased antiarrhythmic dose.
In this cohort of adult patients with Fontan physiology, endothelin blockade with Bosentan resulted in improved 6MWD and MRI derived resting cardiac output, suggesting a positive effect on pulmonary vascular resistance. Bosentan was well tolerated and there were no adverse events requiring hospitalization. Hepatic function was not adversely affected despite elevations in baseline Bilirubin in three patients.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Pulmonary Hypertension: Right Ventricle / Congenital Heart Disease
Abstract Category: 27. Pulmonary Hypertension
Presentation Number: 1208-153
- 2013 American College of Cardiology Foundation