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.

BackgroundThe most common reason for reintervention after a Björk modification of the Fontan procedure, in which the right ventricle (RV) is incorporated into the pulmonary circulation by connecting the right atrial (RA) appendage to the RV directly or with an extra‐anatomic graft, is obstruction or regurgitation of the RA–RV connection. Transcatheter implantation of a valved stent is an appealing option for the treatment of RA–RV conduit dysfunction in these patients. In the present study, we assessed early and intermediate results after transcatheter valve implantation within an obstructed or regurgitant RA–RV modified Fontan pathway.MethodsThrough a retrospective multicenter registry, we collected data from 16 patients with a modified Fontan circulation who were treated with percutaneous Melody or Sapien valve implantation for dysfunction of an extra‐anatomic RA–RV conduit or valve.ResultsAll patients had successful and uncomplicated implantation of a Melody (n = 15) or Sapien 3 (n = 1) valve with hemodynamic and, in most cases, clinical improvement. During a median follow‐up of 3.3 years, 3 patients died of cardiovascular causes unrelated to the procedure or the valve, and no major valve dysfunction was observed.ConclusionPercutaneous transcatheter valve deployment to treat a dysfunctional RA–RV connection after a Björk modification of the Fontan procedure is a viable alternative to surgery, with low procedural risk, and appears to offer good early and intermediate results.© 2016 Wiley Periodicals, Inc.

Background— Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports. Methods and Results— An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II ( P <0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type. Conclusions— TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.