Study validates long-term safety and efficacy of Harmony transcatheter pulmonary valve implant

Reviewed by Emily Henderson, B.Sc.May 19 2022

A study of one year outcomes in the largest cohort to date of Harmony transcatheter pulmonary valve (TPV) patients with congenital heart disease (CHD) and severe pulmonary regurgitation (PR) was presented today as late-breaking clinical research at the Society for Cardiovascular Angiography & Interventions (SCAI) 2022 Scientific Sessions. The findings show Harmony TPV patients had favorable clinical and hemodynamic outcomes, confirming earlier results and demonstrating continued device safety and effectiveness across studies and valve types at one year.

Approximately one in five CHD patients have an abnormality of their right ventricular outflow tract (RVOT) (NLM). Prior to TPV technology, CHD patients were treated with invasive procedures such as open-heart surgery or opted for surgical valve replacement later in life. The Harmony TPV is designed to be a non-invasive, non-surgical treatment option for many of these adolescent and adult CHD patients not previously able to be treated with TPVs.

Data was pooled from the Harmony Native Outflow Tract Early Feasbility Study, Harmony TPV Pivotal Trial, and Continued Access Study. Eligible patients had severe PR by echocardiography or PR fraction ≥30% by cardiac magnetic resonance imaging and a clinical indication for pulmonary valve replacement. Forty-two patients received the TPV22 device and 45 received the modified TPV25 device. Additionally, 19 patients received an early iteration of the 25-mm valve (clinical TPV25) that was later found to have less predictable deployment and discontinued. The primary safety endpoint was freedom from procedure- or device-related mortality at 30 days. Efficacy was assessed as freedom from PR, stenosis, and interventions (≥ moderate PR, mean RVOT gradient > 40 mmHg, device-related RVOT reoperation, and catheter reintervention) through 1 year. Adverse events were adjudicated by a Clinical Events Committee.

A total of 108 patients were catheterized, 106 underwent TPV implants, and 104 remained implanted for >24 hours. The 2 patients who had surgical explantation within 24 hours had received a clinical TPV25 valve. Mean (SD) patient age at baseline was 29.0 (12.7) years; 62.0% were male and 86.1% had an original diagnosis of Tetralogy of Fallot. At 1 year, there were no deaths, and 95.1% of TPV22 and 89.7% of mTPV25 patients were free from PR, stenosis, and interventions. Eighty-five percent of patients or greater had none/trace PR and ≥90% had none/trace paravalvular leak at all follow-up visits.

We knew that Harmony TPV patients were doing well acutely, but this data now validates these findings in the intermediate term. Even a year after implant, the valve is continuing to function well without significant interventions, obstruction or regurgitation. This gives us confidence that we are going down the right treatment path with this pulmonary valve."

Daniel S. Levi, M.D., FSCAI, Mattel Children's Hospital at UCLA, Los Angeles, CA

Researchers will continue to follow this patient cohort and to further demonstrate that Harmony TPV remain safe and effective in the long run.