TPVR with self-expanding Harmony valve associated with ‘excellent’ real-world outcomes

Transcatheter pulmonary valve replacement (TPVR) with Medtronic’s self-expanding Harmony valve is both safe and effective after more than a year, according to new real-world data published in the Journal of the American College of Cardiology.[1]

The Harmony transcatheter pulmonary valve (TPV) was approved by the U.S. Food and Drug Administration (FDA) in 2021 to treat a leaky native or surgically repaired right ventricular outflow tract (RVOT) in pediatric and adult patients with severe pulmonary regurgitation (PR). Medtronic did initiate a voluntary recall in 2022 due to durability issues, but relaunched the device less than one year later.

While early data on the Harmony TPV has been positive, the published studies have not included much information on the clinical outcomes of real-world patients. The team behind this study hoped to change that.

“To surveil for uncommon device-related adverse outcomes and establish therapeutic outcomes in a larger and more heterogeneous population of patients in a real-world environment, we developed a multicenter longitudinal registry of patients treated with self-expanding TPVR,” wrote first author Bryan H. Goldstein, MD, a cardiologist with UMPC Children’s Hospital in Pittsburgh, and colleagues.

Goldstein et al. reviewed data from 243 real-world patients treated at one of 11 U.S. centers through April 2022. Most (91%) patients received the TPV25 device, and all others received the TPV22 device. The median patient age was 31 years old, and the youngest patient was eight years old at the time of the procedure. The most common cardiac diagnoses were tetralogy of Fallot (71%) and valvular pulmonary stenosis (21%). All study participants presented with echocardiography-confirmed moderate or greater PR.

Acute technical success was seen in all but one patient. Of those 242 patients, either no or trivial PR were seen in 96% of patients. Also, 86% of patients were out of the hospital after one day of recovery; the mean length of stay for the other 14% was still just two days. Reasons for those extended hospitalizations included chest pain, ventricular arrhythmia, procedural adverse events and the continuation of pre-TPVR hospitalization.

The study’s median follow-up period was 13 months. At the end of that time, PR was mild or less in 98% of patients, and the median RVOT gradient was 10 mm Hg. Freedom from the composite clinical outcome—hemodynamic dysfunction and/or RVOT reintervention—was seen in 99% of patients after one year and 96% after two years. There were a total of five patient deaths during the follow-up period.

TPV-related thrombosis was seen in 3.4% of patients, diagnosed at a median of four months after the procedure. Four of those patients were managed with medical therapy, three underwent valve-in-valve TPVR and one other patient underwent balloon pulmonary valvuloplasty.

“Although one patient developed TPV thrombosis in the setting of COVID-19 infection, the other cases were not associated with known medical diagnoses,” the authors explained.

Endocarditis, meanwhile, was either diagnosed or suspected in 2.6% of patients after a median of 11 months. Two of those patients were managed with medical therapy, two underwent TPV explantation and two died.

“Short-term self-expanding TPV performance—with regard to hemodynamic and clinical outcomes—is now confirmed in a nontrial cohort,” the authors wrote. “Both TPV22 and TPV25 successfully eliminated PR, maintained freedom from regurgitation, paravalvular leak, and stenosis at >1 year, and demonstrated high rates of freedom from adverse clinical outcomes such as RVOT reintervention, TPV-related thrombosis and endocarditis, and all-cause mortality at one and two years. It is important to note that, unlike in the earlier clinical trials, RVOT reintervention and endocarditis did occur in this registry cohort, albeit not commonly. TPV-related thrombus also occurred at a rate higher than that seen in the clinical trials.”

The small number of adverse events, Goldstein and colleagues noted, serve as a “crucial reminder” of the risks associated with TPVR.

“Provider recognition of these risks in this population ought to promote earlier diagnosis and treatment, which may result in improved clinical outcomes and reduce the need for anatomic RVOT reintervention,” they wrote.

The researchers concluded that real-world outcomes for these patients were “excellent.” They hope to keep following up to learn more as time goes on.

Click here to read the full analysis.

Michael Walter
Michael Walter, Managing Editor

Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.

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