Comparison of Bare Metal Stenting and Percutaneous Pulmonary Valve Implantation for Treatment of Right Ventricular Outflow Tract Obstruction: Use of an X-Ray/Magnetic Resonance Hybrid Laboratory for Acute Physiological Assessment

Background— Treatment of right ventricular outflow tract obstruction is possible with a bare metal stent (BMS), although this treatment causes pulmonary regurgitation. In this study, we assessed the acute physiological effects of BMS versus percutaneous pulmonary valve implantation (PPVI) using an x-ray/magnetic resonance hybrid laboratory. Methods and Results— Fourteen consecutive children (median age, 12.9 years) with significant right ventricular outflow tract obstruction underwent BMS followed by PPVI. Magnetic resonance imaging (ventricular volumes and function and great vessel blood flow) and hemodynamic assessment (invasive pressure measurements) were performed before BMS, after BMS, and after PPVI; all were performed under general anesthesia in an x-ray/magnetic resonance hybrid laboratory. BMS significantly reduced the ratio of right ventricular to systemic pressure (0.75±0.17% versus 0.41±0.14%; P<0.001) with no further change after PPVI (0.42±0.11; P=1.0). However, BMS resulted in free pulmonary regurgitation (21.3±10.7% versus 41.4±7.5%; P<0.001), which was nearly abolished after PPVI (3.6±5.6%; P<0.001). Effective right ventricular stroke volume (right ventricular stroke volume minus pulmonary regurgitant volume) after BMS remained unchanged (33.8±7.3 versus 32.6±8.7 mL/m2; P=1.0) but was significantly increased after revalvulation with PPVI (41.0±8.0 mL/m2; P=0.004). These improvements after PPVI were accompanied by a significant heart rate reduction (75.5±17.7 bpm after BMS versus 69.0±16.9 bpm after PPVI; P=0.006) at maintained cardiac output (2.5±0.5 versus 2.4±0.5 versus 2.7±0.5 mL · min−1 · m−2; P=0.14). Conclusion— Using an x-ray/magnetic resonance hybrid laboratory, we have demonstrated the superior acute hemodynamic effects of PPVI over BMS in patients with right ventricular outflow tract obstruction.

[1]  Audrey C. Marshall,et al.  Endovascular Stenting of Obstructed Right Ventricle–to–Pulmonary Artery Conduits: A 15-Year Experience , 2006, Circulation.

[2]  A. Taylor,et al.  Risk Stratification, Systematic Classification, and Anticipatory Management Strategies for Stent Fracture After Percutaneous Pulmonary Valve Implantation , 2007, Circulation.

[3]  W. Williams,et al.  Intravascular stent prosthesis for right ventricular outflow obstruction. , 1992, Journal of the American College of Cardiology.

[4]  K. Roman,et al.  Differential Regurgitation in Branch Pulmonary Arteries After Repair of Tetralogy of Fallot A Phase‐Contrast Cine Magnetic Resonance Study , 2003, Circulation.

[5]  P. Bonhoeffer,et al.  Percutaneous replacement of pulmonary valve in a right-ventricle to pulmonary-artery prosthetic conduit with valve dysfunction , 2000, The Lancet.

[6]  J. F. Keane,et al.  Prolongation of RV-PA conduit life span by percutaneous stent implantation. Intermediate-term results. , 1995, Circulation.

[7]  D. Hill,et al.  Cardiac catheterisation guided by MRI in children and adults with congenital heart disease , 2003, The Lancet.

[8]  M. Elliott,et al.  Fate of subpulmonary homograft conduits: determinants of late homograft failure. , 1998, The Journal of thoracic and cardiovascular surgery.

[9]  Palaniswamy Vijay,et al.  Right ventricular outflow tract reconstruction with an allograft conduit in non-ross patients: risk factors for allograft dysfunction and failure. , 2005, The Annals of thoracic surgery.

[10]  A. Taylor,et al.  Assessment of differential branch pulmonary blood flow: a comparative study of phase contrast magnetic resonance imaging and radionuclide lung perfusion imaging , 2006, Heart.

[11]  E. Bruckheimer,et al.  Single coronary artery complicating stent implantation for homograft stenosis in tetralogy of Fallot. , 1997, Catheterization and cardiovascular diagnosis.

[12]  A. Taylor,et al.  Physiological and Clinical Consequences of Relief of Right Ventricular Outflow Tract Obstruction Late After Repair of Congenital Heart Defects , 2006, Circulation.

[13]  P. Bonhoeffer,et al.  Percutaneous implantation of pulmonary valves for treatment of right ventricular outflow tract dysfunction , 2008, Cardiology in the Young.

[14]  P. Yock,et al.  Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation. , 1984, Circulation.

[15]  R. Razavi,et al.  Percutaneous Pulmonary Valve Implantation in Humans: Results in 59 Consecutive Patients , 2005, Circulation.

[16]  A. Taylor,et al.  Images in cardiovascular medicine. Transcatheter right ventricular outflow tract intervention: the risk to the coronary circulation. , 2006, Circulation.

[17]  F. Mohr,et al.  Bovine jugular vein conduit for right ventricular outflow tract reconstruction: evaluation of risk factors for mid-term outcome. , 2006, The Annals of thoracic surgery.

[18]  B. McCrindle,et al.  Endovascular stents in the pulmonary circulation. Clinical impact on management and medium-term follow-up. , 1995, Circulation.

[19]  Cengizhan Ozturk,et al.  Invasive human magnetic resonance imaging: Feasibility during revascularization in a combined XMR suite , 2005 .

[20]  Vivek Muthurangu,et al.  Percutaneous Pulmonary Valve Implantation: Impact of Evolving Technology and Learning Curve on Clinical Outcome , 2008, Circulation.

[21]  David Bruce Lewis,et al.  Factors Affecting Longevity of Homograft Valves Used in Right Ventricular Outflow Tract Reconstruction for Congenital Heart Disease , 2000, Circulation.

[22]  A. Taylor,et al.  Physiological consequences of percutaneous pulmonary valve implantation: the different behaviour of volume- and pressure-overloaded ventricles. , 2007, European heart journal.

[23]  Silvia Schievano,et al.  Variations in right ventricular outflow tract morphology following repair of congenital heart disease: implications for percutaneous pulmonary valve implantation. , 2007, Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance.

[24]  Younes Boudjemline,et al.  Percutaneous insertion of the pulmonary valve. , 2002, Journal of the American College of Cardiology.

[25]  Alastair J. Martin,et al.  Balloon sizing and transcatheter closure of acute atrial septal defects guided by magnetic resonance fluoroscopy: Assessment and validation in a large animal model , 2005, Journal of magnetic resonance imaging : JMRI.

[26]  Cengizhan Ozturk,et al.  X-Ray Fused With Magnetic Resonance Imaging (XFM) to Target Endomyocardial Injections: Validation in a Swine Model of Myocardial Infarction , 2006, Circulation.

[27]  S. Aggarwal,et al.  Is stent placement effective for palliation of right ventricle to pulmonary artery conduit stenosis? , 2007, Journal of the American College of Cardiology.

[28]  J. Lock,et al.  Implantation and Intermediate‐Term Follow‐up of Stents in Congenital Heart Disease , 1993, Circulation.