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Transcatheter pulmonary valve (TPV) technology continues to be refined as researchers report good long-term performance of the original Melody valve.

Medtronic's Harmony valve, designed for congenital heart disease (CHD) patients with right ventricular outflow tract (RVOT) abnormalities, was shown to work in people without surgical right ventricle-to-pulmonary artery (RV-PA) conduits.

FDA approval for Harmony could come early next year, according to the discussion during this year's virtual .

Meanwhile, the Melody valve -- approved since 2010 -- was found to prolong the life of surgical RVOT conduits and bioprosthetic pulmonary valves up to 10 years in some patients.

Both studies were presented during an online late-breaking science session at SCAI.

New (and Improving) Harmony Valve

The investigational Harmony TPV met safety and efficacy goals in a pivotal trial, as researchers continue to wait for data on a newer design iteration.

In 50 people with pulmonary regurgitation without RV-PA conduits, 100% enjoyed freedom from procedure- or device-related mortality at 30 days following device placement, reported John Cheatham, MD, of Nationwide Children's Hospital in Columbus, Ohio.

At 6 months, 89% had acceptable hemodynamic function and no valve interventions, a figure that grew to 91% when including the small cohort from an early feasibility study (EFS), Cheatham told the audience.

Notably, investigators had started the study with the TPV22 version of the Harmony that was used in the EFS. They then tried the "clinical TPV25" version before settling on the "modified TPV25" (mTPV25) model, a 25-mm tissue valve that is shorter in length and has wider diameters on the inflow and outflow ends of the device to improve the valve frame deployment and performance.

Just 10 out of the 50 patients in the observational study had received the new mTPV25 and had data through 1 month.

Data from the Harmony development program is currently being analyzed and submitted for premarket approval by the FDA, Cheatham said. He added that he anticipated commercial approval by the end of this year or first quarter of next year.

After screening of 243 people, 50 were included in the study. These were patients who met indications for pulmonary valve replacement. The group was 38% women or girls, with a median age of 28 years.

Harmony device recipients went from 72% having severe pulmonary regurgitation at baseline to 89% having none/trace regurgitation at 1 and 6 months. Paravalvular leak was 89% none/trace at 6 months.

"Severe PR [pulmonary regurgitation] after surgical correction of RVOT anomalies remains an important hemodynamic abnormality and a challenge to correct using transcatheter technologies," Cheatham said.

"The Continued Access Study is underway using the TPV22 and mTPV25," he noted. "The delivery system is being modified in order to provide even more control in the delivery and deployment of both the TPV22 and the mTPV25 devices."

The Melody Valve at 10 Years

Long-term functionality of the original Melody TPV was confirmed from the Investigational Device Exemption study cohort, according to a separate report.

Among 149 people who got the device, 54% remained free from TPV dysfunction at 10 years, counting RVOT reoperation, catheter re-intervention, or hemodynamic dysfunction of the TPV. Outcomes were significantly better for people who were at least 22 years old at TPV implant, reported Thomas Jones, MD, of Seattle Children's Hospital.

Most patients who met criteria for TPV dysfunction had had reinterventions, he noted.

"This is the first transcatheter valve study and the longest follow-up reported to date for any TPV. Ten years after Melody TPV implantation, valve function remains stable," Jones concluded.

"The Melody valve fulfills its intended design goal of prolonging the useful life of surgically implanted RVOT conduits and bioprosthetic valves and reducing the lifetime burden of repeat open heart operations," he said.

His group observed 84% freedom from major stent fracture at 10 years. The hazard of major stent fracture appeared to be early and remained stable after 5 years.

The annualized incidence of endocarditis of the Melody valve was 2% per patient-year over long-term follow-up.

Included in the study were 149 people who had the Melody implanted for at least 24 hours (64% men or boys, median age 19 years). Nearly half had severe pulmonary regurgitation at baseline.

Follow-up lasted for a median 8.4 years, with 93.5% of the group having 10-year data available.