Abstract 1932: Percutaneous Pulmonary Valve Implantation - The First North American Trial
Background: Children with complex congenital heart disease who require reconstruction of their right ventricular outflow tracts (RVOT) often develop outflow tract obstruction and/or regurgitation. While stent implantation has been used to relieve such stenosis, it results in increased regurgitation.
Objective: This study is the first North American feasibility analysis of a percutaneously placed pulmonary valve, reviewing clinical outcomes with objective evaluation by echocardiography, exercise testing, MRI and cardiac output measurements prior to and after implantation.
Methods: Thirteen patients, 7 females, 15.8 ± 2.4 years old (range 13 to 21 years) and 56.3 ± 8.2 kg (range 42.2 to 72.3 kg), 5 to 17 years after surgical RVOT reconstruction underwent percutaneous pulmonary valve implantation (PPVI) between October 2005 and May 2006. Fallot’s tetralogy, pulmonary atresia with ventricular septal defect, persistent truncus arteriosus, and Taussig-Bing malformation constituted the underlying cardiac defects. Patients were seen before the procedure with an echocardiogram, heart MRI (n = 7), exercise test (n = 11) and clinical examination. After the procedure they were seen at 1, 3, and 6 months, with an echocardiogram, ECG, and chest x-ray. Exercise test was performed at 3 months and cardiac MRI at 6 months.
Results: Patients were discharged home the day following the procedure. No complications such as stent dislodgment or fracture, stroke, valve malfunction or urgent surgery were identified in the 6 month follow-up period. The right ventricular systolic pressure (RVSP) fell from 65.1 ± 19.1 to 45.6 ± 10.7 mm Hg, ( p < 0.01), RVSP/aotic pressure ratio fell from 0.75 ± 0.2 to 0.47 ± 0.1, ( p < 0.0005), right ventricular to pulmonary artery peak pressure gradient fell from 34.6 ± 19.9 to 13.4 ± 7.6 mm Hg, ( p < 0.004) and pulmonary regurgitation score fell from 2.9 ± 0.3 to 0.75 ± 0.5 , ( n = 12, p < 0.0001) 1 day after PPVI. Exercise testing VO2 max (23.95 ± 4.1 to 25.1 ± 3.96 ml/kg/min, ( p < 0.35) and procedural cardiac output measurements did not change significantly.
Conclusion: PPVI is feasible and carries very low morbidity. Data suggests a significant improvement in right heart hemodynamics. Long-term valve performance requires further observations.