Ten-Year Results Support Use of Melody Transcatheter Pulmonary Valve

Thomas Jones, MD

Results of a 10-year US Investigational Device Exemption trial is shedding light on the safety and efficacy of the Melody transcatheter pulmonary valve (TPV).

Presented at the Society for Cardiovascular Angiography and Interventions (SCAI) 2020 scientific sessions, results suggest use of Melody TPV was associated with favorable outcomes in regard to long-term function, safety, and efficacy for congenital patients who underwent valve implantation within an existing dysfunctional right ventricular outflow tract (RVOT) conduit or bioprosthetic pulmonary valve.

"Having long-term data now available is an important milestone especially for the pediatric patient population who are growing and changing so rapidly during a ten-year period," said lead investigator Thomas K. Jones, MD, director of cardiac catheterization at Seattle Children's in Seattle, in a statement from the SCAI. "While the data 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."

To evaluate the safety and performance of the Melody TPV, the current trial was designed to assess acute and short-term results from use of the device. In total, 150 patients were included in the trial, of which 71 were 18 years old or younger and the median age was 19 years.

For inclusion in the trial, patients needed to be 5 years of age or older and weight at least 30 kg, as well as meeting multiple other criteria depending on NYHA class. Patients were excluded from the trial if they had active endocarditis, life expectancy of less than 1 year, presence of an obstruction of central veins preventing advancement of delivery system, known intravenous drug use, or a positive pregnancy test 24 hours prior to procedure.

Investigators noted pulmonary regurgitation was the most common indication for intervention, representing 53% of patients. The other most common indications were RVOT obstruction (26%) and both event simultaneously occurring, which happened in 21% of patients.

Previously presented mid-term results from the trial, which included 4.5 years of follow-up, indicated 32 patients received RVOT reintervention for obstruction (27), endocarditis (2), right ventricular dysfunction (1), or other reasons (2). Additionally, rates of freedom from reintervention at this point in the trial were 76±4% and 92±3%, respectively.

The primary efficacy outcome of the study was TPV dysfunction, which investigators defined as reoperation, catheter reintervention, or hemodynamic dysfunction. Safety outcomes of interest included serious device-related adverse events, stent fracture, catheter reintervention, surgical conduit replacement, and death.

Of the 150 originally implanted as part of the study, 58 were included in the 10-year follow-up analysis. At 10 years, 90% of patients were free from all-cause mortality, 79% were free from surgical reintervention, and 72% were free from catheter intervention. Investigators noted 54% of patients were free from TPV dysfunction, reintervention, and hemodynamic dysfunction at 10 years. In analyses stratified by age, 65% of adults were free of TPV dysfunction at 10 years compared to just 47% of the study’s pediatric patients.

Additionally, investigators noted 81% of patients were free from TPV-related endocarditis and 76% were free from any endocarditis events. Results suggested an event rate of 2.96 per 1000 patient-years for endocarditis and 2.00 per 1000 patient-years for TPV-endocarditis.

This study, “The Melody Transcatheter Pulmonary Valve: 10-Year Outcomes in the Original US Investigational Device Exemption Trial Cohort,” was presented at SCAI 2020.