Melody Transcatheter Pulmonary Valve (TPV) Post-Market Surveillance Study

• Clinical Performance over five years. Freedom from the following events: * explant * reintervention * stent fracture * valve dysfunction * device or procedure related death [ Time Frame: August 2014 ] [ Designated as safety issue: No ]
  

• Procedural success [ Time Frame: August 2014 ] [ Designated as safety issue: No ]
  
• Incidence of device and procedure related adverse events [ Time Frame: August 2014 ] [ Designated as safety issue: No ]
  
• Hemodynamic Performance [ Time Frame: August 2014 ] [ Designated as safety issue: No ]
  

Background: Patients with congenital heart defects involving the right ventricular outflow tract, such as Tetralogy of Fallot, Pulmonary Atresia and Ventricular Septal Defect, Truncus Arteriosus, and Transposition of the Great Arteries are commonly treated by surgical placement of right ventricle (RV) to pulmonary artery (PA) conduits. However, despite major advances in terms of durability, the life span of prosthetic conduits is relatively limited, and most patients are committed to multiple cardiac surgeries over their lifetime.1 Common failure modes for conduits include calcification, intimal proliferation, and graft degeneration, which result in stenosis and regurgitation; alone or in combination. Both stenosis and regurgitation place an increased hemodynamic burden on the right ventricle, and can result in reduced cardiac function. Percutaneous placement of stents within the conduit can provide palliative relief of stenosis, and may eliminate or postpone the need for surgery.However, stent placement is only useful to treat conduit stenosis; patients with predominant regurgitation or mixed stenosis and regurgitation cannot be adequately treated with stents.

Although pulmonary regurgitation is generally well tolerated for many years when the pulmonary vasculature is normal, long-term follow-up has revealed its detrimental effect on right and left ventricular function. Chronic volume overload of the RV leads to ventricular dilatation and impairment of systolic and diastolic function, which in the long term leads to reduced exercise tolerance, arrhythmias, and an increased risk of sudden death. However, restoration of pulmonary valve competence at an appropriate time has resulted in improvement of right ventricular function, incidence of arrhythmias, and effort tolerance.

Surgical replacement of RVOT conduits can be performed with low mortality; however, the risks of cardiopulmonary bypass, infection, bleeding, and ventricular dysfunction remain. Furthermore, adolescents and adults are reluctant to undergo reoperation where the longevity of the new conduit does not guarantee freedom from future operations. Thus, a potentially less invasive approach for treatment of RVOT conduit dysfunction would be welcomed by patients and their families.

Towards this aim, NuMed Inc, Medtronic Inc and Professor Phillip Bonhoeffer have developed the Melody™ TPV and the Ensemle™ Transcatheter Delivery System to allow percutaneous transcatheter placement of a biological valved stent. Animal experiments have demonstrated the device can be implanted via a catheter with good functional results. Human clinical experience shows that transcatheter implantation can be performed safely in patients and provides an acute improvement in objective measures of cardiac performance. However, the published clinical experience is limited to a maximum of three and a half years of follow-up.

As long-term survival has improved for congenital heart patients (CHD), Quality of Life has become an increasing concern for the patients, parents and physicians. In addition to mortality, significant morbidities after surgery for CHD need to be considered. These include the need for reintervention, cardiovascular complications, exercise limitations, impaired functional status and quality of life15.

A minimally invasive intervention such as a Melody™ TPV implant seems to imply that patients have less discomfort and less impairment of their daily activities than conventional surgery. It also often means a lower risk and cost.

Therefore, the purpose of the proposed study is to collect data to further characterize the long-term clinical performance of the Medtronic Melody™ TPV in the post market environment over a period of five years after transcatheter placement in patients with dysfunctional conduits. In addition, it is the intention of this study to observe quality of life and health states of these patients before and after the intervention as well as during the long -term follow-up.

Device description: The Medtronic Melody™ Transcatheter Pulmonary Valve (TPV) consists of a segment of bovine jugular vein with a thinned down venous wall having a central, competent venous valve. This valve is attached to a Platinum/Iridium stent. The Medtronic Melody™ TPV is implanted via the Ensemble™ Transcatheter Delivery System. This system comprises a balloon in balloon (BiB) deployment design at its distal end onto which the Melody™ TPV is front-loaded and crimped.To deploy the Melody™ TPV, the inner balloon is inflated, followed by inflation of the outer balloon. The Medtronic Melody™ TPV and the Ensemble™ Transcatheter Delivery System obtained CE mark on September 29, 2006 for commercial release in Europe and a Medical Device License from Health Canada for release on the Canadian market on December 15, 2006

Indication: The Melody™ TPV is indicated for use in patients with RVOT conduit dysfunction: either conduit regurgitation, conduit stenosis, or a combination of both. The intended clinical performance of the Melody™ TPV is to restore and maintain pulmonary valve competence for patients with conduit regurgitation and to provide relief of obstruction without inducing significant regurgitation for patients with conduit stenosis.

Subject Population: Patients with dysfunctional RVOT conduits. All prospective subjects will be selected by their physician(s) as potential candidates to receive a Melody™ TPV using the Ensemble™ Transcatheter Delivery System as part of their normal care and independent from possible participation in this study. If the subject fulfills the subject selection criteria she/he will be asked for participation.

Study plan: The primary objective is to assess the long-term clinical performance of the Melody™ TPV for a period of five years across the spectrum of patients with dysfunctional RVOT conduits that have a clinical indication for invasive intervention. The secondary objective is to assess the quality-of-life of enrolled subjects of age 15 and older.

This objective will be accomplished by a prospective interventional clinical study involving 60 subjects in which implantation of the Melody™ TPV has been performed or attempted, distributed among a maximum of seven participating centers in Europe and Canada.