Background— Percutaneous pulmonary valve implantation was introduced in the year 2000 as a nonsurgical treatment for patients with right ventricular outflow tract dysfunction. Methods and Results— Between September 2000 and February 2007, 155 patients with stenosis and/or regurgitation underwent percutaneous pulmonary valve implantation. This led to significant reduction in right ventricular systolic pressure (from 63±18 to 45±13 mm Hg, P <0.001) and right ventricular outflow tract gradient (from 37±20 to 17±10 mm Hg, P <0.001). Follow-up ranged from 0 to 83.7 months (median 28.4 months). Freedom from reoperation was 93% (±2%), 86% (±3%), 84% (±4%), and 70% (±13%) at 10, 30, 50, and 70 months, respectively. Freedom from transcatheter reintervention was 95% (±2%), 87% (±3%), 73% (±6%), and 73% (±6%) at 10, 30, 50, and 70 months, respectively. Survival at 83 months was 96.9%. On time-dependent analysis, the first series of 50 patients (log-rank test P 25 mm Hg (log-rank test P =0.01) were associated with a higher risk of reoperations. Conclusions— Percutaneous pulmonary valve implantation resulted in the ability to avoid surgical right ventricular outflow tract revision in the majority of cases. This procedure might reduce the number of operations needed over the total lifetime of patients with right ventricle–to–pulmonary artery conduits.

Background— Right ventricular outflow tract (RVOT) reconstruction with valved conduits in infancy and childhood leads to reintervention for pulmonary regurgitation and stenosis in later life. Methods and Results— Patients with pulmonary regurgitation with or without stenosis after repair of congenital heart disease had percutaneous pulmonary valve implantation (PPVI). Mortality, hemodynamic improvement, freedom from explantation, and subjective and objective changes in exercise tolerance were end points. PPVI was performed successfully in 58 patients, 32 male, with a median age of 16 years and median weight of 56 kg. The majority had a variant of tetralogy of Fallot (n=36), or transposition of the great arteries, ventricular septal defect with pulmonary stenosis (n=8). The right ventricular (RV) pressure (64.4±17.2 to 50.4±14 mm Hg, P <0.001), RVOT gradient (33±24.6 to 19.5±15.3, P <0.001), and pulmonary regurgitation (PR) (grade 2 of greater before, none greater than grade 2 after, P <0.001) decreased significantly after PPVI. MRI showed significant reduction in PR fraction (21±13% versus 3±4%, P <0.001) and in RV end-diastolic volume (EDV) (94±28 versus 82±24 mL · beat ⁻¹ · m ⁻² , P <0.001) and a significant increase in left ventricular EDV (64±12 versus 71±13 mL · beat ⁻¹ · m ⁻² , P =0.005) and effective RV stroke volume (37±7 versus 42±9 mL · beat ⁻¹ · m ⁻² , P =0.006) in 28 patients (age 19±8 years). A further 16 subjects, on metabolic exercise testing, showed significant improvement in V̇ o ₂ max (26±7 versus 29±6 mL · kg ⁻¹ · min ⁻¹ , P <0.001). There was no mortality. Conclusions— PPVI is feasible at low risk, with quantifiable improvement in MRI-defined ventricular parameters and pulmonary regurgitation, and results in subjective and objective improvement in exercise capacity.

Background— The timing of pulmonary valve replacement (PVR) for free pulmonary incompetence in patients with congenital heart disease remains a dilemma for clinicians. We wanted to assess the determinants of improvement after PVR for pulmonary regurgitation over a wide range of patient ages and to use any identified predictors to compare clinical outcomes between patient groups. Methods and Results— Seventy-one patients (mean age 22±11 years; range, 8.5 to 64.9; 72% tetralogy of Fallot) underwent PVR for severe pulmonary regurgitation. New York Heart Association class improved after PVR (median of 2 to 1, P <0.0001). MRI and cardiopulmonary exercise testing were performed before and 1 year after intervention. After PVR, there was a significant reduction in right ventricular volumes (end diastolic volume 142±43 to 91±18, end systolic volume 73±33 to 43±14 mL/m ² , P <0.0001), whereas left ventricular end diastolic volume increased (66±12 to 73±13 mL/m ² , P <0.0001). Effective cardiac output significantly increased (right ventricular: 3.0±0.8 to 3.3±0.8 L/min, P =0.013 and left ventricular: 3.0±0.6 to 3.4±0.7 L/min, P <0.0001). On cardiopulmonary exercise testing, ventilatory response to carbon dioxide production at anaerobic threshold improved from 35.9±5.8 to 34.1±6.2 ( P =0.008). Normalization of ventilatory response to carbon dioxide production was most likely to occur when PVR was performed at an age younger than 17.5 years ( P =0.013). Conclusions— A relatively aggressive PVR policy (end diastolic volume <150 mL/m ² ) leads to normalization of right ventricular volumes, improvement in biventricular function, and submaximal exercise capacity. Normalization of ventilatory response to carbon dioxide production is most likely to occur when surgery is performed at an age ≤17.5 years. This is also associated with a better left ventricular filling and systolic function after surgery.

Our aim was to identify sub-groups of right ventricular outflow tract morphology that would be suitable for percutaneous pulmonary valve implantation and to document their prevalence in our patient population. Eighty-three consecutive patients with right ventricular outflow tract dysfunction (5-41 years, 76% tetralogy of Fallot) referred to our center for cardiovascular magnetic resonance were studied. A morphological classification was created according to visual assessment of three-dimensional reconstructions and detailed measurement. Diagnosis, right ventricular outflow tract type, surgical history and treatment outcomes were documented. Right ventricular outflow tract morphology was heterogeneous; nevertheless, 5 patterns were visually identified. Type I, a pyramidal morphology, was most prevalent (49%) and related to the presence of a transannular patch. Other types (II-V) were seen more commonly in patients with conduits. Two patients had unclassifiable morphology. Ninety-five percent of patients were assigned to the correct morphological classification by visual assessment alone. Percutaneous pulmonary valve implantation was performed successfully in 10 patients with Type II-V morphology and in 1 patient with unclassifiable morphology. Percutaneous implantation was not performed in patients with Type I morphology. Only right ventricular outflow tract diameters < 22 mm in diameter were suitable for the current device. We have created a morphological classification of the RVOT in patients referred for assessment of RVOT dysfunction. Though only 13% of our patients underwent percutaneous implantation, > 50% of outflow tract morphologies may be suitable for this approach, in particular with the development of new devices appropriate for larger outflow.

To determine if magnetic resonance (MR) imaging data can be used to create rigid models that are accurate representations of the right ventricular outflow tract (RVOT) and pulmonary trunk anatomy and if such models can be used to refine the selection of patients for percutaneous pulmonary valve implantation (PPVI). Institutional review board approval and informed patient consent were obtained. Twelve patients' MR data were analyzed and elaborated for input into a rapid prototyping (RP) system. RP models were successfully built and presented to two experienced cardiologists, who were retrospectively asked if they would have attempted PPVI. Their responses were compared with the documented decisions and outcomes of PPVI. For four subjects, both cardiologists correctly determined, on the basis of MR image or three-dimensional (3D) RP model findings, that PPVI should not have been attempted. Two patients in whom PPVI was attempted were considered to be unsuitable for the procedure after balloon sizing, and in another two patients, implantation was unsuccessful because of device instability. For the four patients in whom PPVI was suitable and the four in whom it was unsuitable, observers 1 and 2 correctly determined suitability for PPVI in four and two patients, respectively, by using the MR images alone. Both observers correctly determined the suitability of five patients by using the 3D models alone. Using 3D RP models resulted in more accurate selection of patients for PPVI than did using MR images.

Background— We analyzed the incidence, risk factors and treatment options for stent fracture after percutaneous pulmonary valve (PPV) implantation (PPVI). Methods and Results— After PPVI, 123 patients had chest x-ray in anteroposterior and lateral projection, echocardiography, and clinical evaluation during structured follow-up. Of these 123 patients, 26 (21.1%) developed stent fracture 0 to 843 days after PPVI (stent fracture–free survival at 1 year, 85.1%; at 2 years, 74.5%; and at 3 years, 69.2%). Stent fracture was classified as type I: no loss of stent integrity (n=17); type II: loss of integrity with restenosis on echocardiography (n=8); and type III: separation of fragments or embolization (n=1). In a multivariate Cox regression, we analyzed various factors, of which 3 were associated with a higher risk of stent fracture: implantation into “native” right ventricular outflow tract ( P =0.04), no calcification along the right ventricular outflow tract (judged with fluoroscopy, P =0.02), recoil of PPV (qualitatively, PPV diameter in frontal or lateral plane with fully inflated balloon > diameter after balloon deflation, P =0.03). Substernal PPV location, high-pressure post-PPVI dilatation of PPV, pre-PPVI right ventricular outflow tract gradients, and other indicators of PPV compression or asymmetry did not pose increased risk. Patients with type I fracture remain under follow-up. Patients with type II fracture had 2nd PPVI or are awaiting such procedure, and 1 patient with type III fracture required surgical explantation. Conclusion— Stent fracture after PPVI can be managed effectively by risk stratification, systematic classification, and anticipatory management strategies. Serial x-ray and echocardiography are recommended for surveillance.