May 15, 2020
Medtronic Presents Data on Melody and Harmony TPV Devices for Congenital Heart Disease
May 15, 2020—Medtronic announced the results from two late-breaking clinical trials presented at the Society for Cardiovascular Angiography and Interventions (SCAI) 2020 Scientific Sessions Virtual Conference held May 14–16. The data are 10-year outcomes from the Melody Transcatheter Pulmonary Valve (TPV) Therapy trial and first-ever data from the Harmony TPV pivotal trial.
The company advised that the Melody TPV Therapy trial demonstrated strong long-term hemodynamic and safety outcomes. The investigational Harmony TPV pivotal trial met safety and efficacy endpoints for hemodynamic function at 6 months.
The Melody TPV trial studied 150 patients who received implantation of the device with ages ranging from age 7 to 53 years and median age of 19 years. The primary indication for intervention was pulmonary regurgitation (PR).
Investigators assessed the Melody device's long-term functionality, or TPV dysfunction, which is defined as reoperation, catheter reintervention, or hemodynamic dysfunction (ie, moderate or greater PR and/or mean right ventricular outflow tract [RVOT] gradient > 40 mm Hg). The safety outcomes included serious device-related adverse events, stent fracture, catheter reintervention, surgical conduit replacement, and mortality rate.
According to the company, the 10-year data for the Melody TPV demonstrated the following:
- Sustained long-term function when compared with the historical control of surgical conduit
- Consistent hemodynamics through 10 years as measured by stable RVOT gradients
- Strong valve efficacy with 97% none/trace/mild PR at 10 years
- Annualized incidence of TPV-related endocarditis was 2% per patient-year, over the course of long-term follow-up
- Freedom from major stent fracture 84% at 10 years, steady after 5 years
- Freedom from any reintervention (surgical or catheter) was 61% at 10 years
“Having long-term data is an important milestone especially for this pediatric patient population who are growing and changing so rapidly during a 10-year period,” said Thomas K. Jones, MD, commenting in Medtronic's press release. “While the study reinforces the longevity, durability, and efficacy of the Melody TPV, it will also serve as a study model for future evaluations of novel pediatric congenital heart disease technologies.” Dr. Jones is Director of Cardiac Catheterization at Seattle Children’s in Seattle, Washington.
In the Harmony TPV pivotal trial, the device was evaluated for patients with RVOT malformations who require a correction to their structural malformation early in life and need a minimally invasive option to restore pulmonary valve function and are without a conduit. The trial is a prospective, nonrandomized study evaluating procedural success, safety, and performance of the Harmony TPV device. The study was active across 12 sites in the United States, Canada, and Japan. It was composed of 50 patients with a mean age of 29 ± 11 years.
According to the company, a rigorous patient selection process included those with severe PR after RVOT malformation repair and an indication for surgical placement of an RV-pulmonary artery conduit or bioprosthetic pulmonary valve. Because of the highly variable anatomy of the patient population, the study required careful screening to assess device fit.
The pivotal study builds on the initial early feasibility study (EFS) to evaluate the safety and effectiveness of this minimally invasive alternative to open surgery. Harmony TPV was designed to treat patients with RVOT anomalies who develop severe PR typically when a previous repair fails. The device is limited to investigational use and not approved for sale or distribution in the world.
The first-ever data from the Harmony TPV pivotal trial included:
- The study met its primary safety and effectiveness endpoints of freedom from procedure- or device-related mortality and met its hemodynamic function target at 6 months
- 100% of patients experienced freedom from procedure- or device-related mortality at 30 days
- Acceptable hemodynamic function at 6 months was achieved in 89% of the pivotal trial participants
- For the prespecified primary endpoint analysis, 91% of patients from both the EFS and pivotal trial achieved acceptable hemodynamic function, surpassing the performance target of 75%
- 84% of patients were free from device failure at 6 months
- At 6 months, 94% of patients had no or mild pulmonary regurgitation and 97% had no or mild paravalvular leak
“These pivotal data support the rationale for a potential new therapy designed specifically for the right ventricular outflow tract,” stated the study's lead principal investigator John P. Cheatham, MD, in Medtronic's announcement. “If future study data continues to be strong, we’re hopeful that Harmony may potentially impact this critical, hard-to-treat segment of patients, who have limited treatment choices with current transcatheter technologies.” Dr. Cheatham is Professor Emeritus, Department of Pediatrics, Cardiology at Nationwide Children's Hospital in Columbus, Ohio.