Asnes, Jeremy D

BACKGROUND: The Harmony transcatheter pulmonary valve (TPV) is designed to treat severe pulmonary regurgitation in the native or surgically repaired right ventricular (RV) outflow tract. Early outcomes after TPV replacement with the Harmony valve have been positive, but longer-term data are limited. METHODS: The study included patients who received a commercially available TPV22 or TPV25 device as part of the nonrandomized, prospective Native Outflow Tract Early Feasibility Study, Harmony Pivotal Trial, and Continued Access Study. Patients completed at least 3 years of follow-up, and outcomes to 5 years were reported when available. RESULTS: Eighty-nine patients were catheterized, and 86 were successfully implanted with a Harmony TPV. Median duration of follow-up was 5 (range 0–6) years in the TPV22 group and 3 (1–4) years in the TPV25 group. At 3 years, all patients with a TPV22 and 96% of those with a TPV25 had ≤mild pulmonary regurgitation. By magnetic resonance imaging, significant improvements from preimplant to 2 years were observed in RV end-diastolic volume index, RV to left ventricular end-diastolic volume ratio, and effective RV stroke volume (all P <0.001). SF-36 quality-of-life scores improved after Harmony implantation and were sustained over 3 years. Early cases of ventricular tachycardia resolved, and there were no new arrhythmias. Adverse events up to 5 years included 3 deaths unrelated to the device or procedure, 2 cases of endocarditis that were treated (1 medically, 1 transcatheter debulking of a vegetation) and resolved, 6 patients with RV outflow tract obstruction or thrombosis resulting in valve-in valve procedures, and 1 major stent fracture resulting in surgical explant. CONCLUSIONS: At 3 to 5 years, Harmony TPV replacement resulted in sustained valve competence, beneficial cardiac remodeling, and improved quality of life. Continued monitoring is needed to assess long-term outcomes and valve performance. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01762124; NCT02979587.

AbstractBackgroundThe Harmony TPV25 transcatheter pulmonary valve (Medtronic Inc.) is constructed with a self‐expanding stent frame comprising six zigged nitinol wires sewn together and covered with knitted polyester fabric, with flared inflow and outflow ends and a porcine pericardial valve sutured to the central portion of the device. It was approved for treatment of pulmonary regurgitation after prior right ventricular outflow tract repair in 2021. Early outcomes of this procedure have been excellent, but little is known about valve durability or ultimate mechanisms of dysfunction.MethodsWe collected data on patients who underwent reintervention for TPV25 dysfunction and described findings related to distortion of the stent frame and tissue accumulation.ResultsWe describe six patients who underwent valve‐in‐valve implant for TPV25 obstruction (peak catheterization gradient peak 28–73 mmHg) 10–28 months after implant. In all cases, there was tissue accumulation within the inflow and valve‐housing segments of the device and deformation of the self‐expanding valve frame characterized by variable circumferential narrowing at the junction between the valve housing and the inflow and outflow portions of the device, with additional geometric changes in all segments. All six patients underwent valve‐in‐valve implant that results in a final peak gradient ≤10 mmHg and no regurgitation.DiscussionThe occurrence of short‐term Harmony TPV25 dysfunction in multiple patients with a similar appearance of frame distortion and tissue accumulation within the inflow and valve housing portions of the device suggests that this may be an important failure mechanism for this valve. Potential causes of the observed findings are discussed. It is possible to treat this mechanism of TPV25 dysfunction with valve‐in‐valve implant using balloon expandable transcatheter valves.