Matthew Gillespie, Children’s Hospital of Philadelphia, Philadelphia, USA, and others reported in Circulation: Cardiovascular Interventions that transcatheter pulmonary valve implantation (TPVI) with the Melody valve (Medtronic) may be an effective treatment option for patients with failed bioprosthetic valves.
Gillespie et al wrote that bioprosthetic valves were becoming the “prosthesis of choice” for surgical pulmonary valve replacement in older patients and stated: “As the population of patients with congenital heart disease ages and the importance of long-term pulmonary valve competence achieves priority, it is likely that the use of bioprosthetic valves for pulmonary valve implantation replacement will increase. Extending the functional life of failed bioprosthetic valves via TPVI is likely to increase in kind.” However, they added that there is little published data for the use of TPVI with the Melody valve in failed bioprosthetic valves and, in the USA, the device is not licensed for this indication. Gillespie et al reported: “The purpose of this study was to review the combined experience with the Melody valve implantation in pulmonary bioprosthetic valves from eight centres in the United States.”
The authors reviewed data from patients (across eight centres) who had undergone TPVI with the Melody valve for failed bioprosthetic valves between April 2007 and January 2012. Of the 104 patients who met the study’s inclusion criteria, four were excluded because they did not receive the Melody valve. The underlying diagnosis in the majority of patients (71%) was tetralogy of Fallot, almost half of patients had combined regurgitation and stenosis as the presenting mechanism for failure of the bioprosthetic valve, and more than three-quarters had moderate-to-severe regurgitation.
Gillespie et al commented: “The Melody valve was successfully implanted in the intended position in all cases. There were no deaths and no serious procedure adverse events”. They added that after implantation of the Melody valve, right heart haemodynamics were significantly improved, the peak right ventricle to pulmonary artery (RV-PA) gradient decreased from 38.7±16.3mmHg to 10.9±6.7mmHg (p<0.001), and all but two patients had postimplant gradients of <25mmHg.
After a median follow-up of 12 months, there were two deaths—both unrelated to the Melody valve. Stent fractures were identified (via fluoroscopic assessment) in two patients. The authors stated that “one of the most significant concerns with the Melody valve implanted into right ventricular outflow tract (RVOT) conduits has been stent fracture” and added that the low incidence of stent fracture observed in the study “suggests that the structural framework present in most bioprosthetic valves protects the Melody from compressive and rotational forces associated with cardiac contraction, similar to the benefit demonstrated with pre-stenting of stenotic RV-PA conduits.” They added that, size permitting, that pre-stenting of the bioprosthetic valve may provide additional support to the Melody valve. According to Gillespie et al, valve function was “generally excellent” on follow-up echocardiograms in patients with an intact Melody valve.
Concluding, the authors wrote: “This remarkable success rate, with low procedural morbidity, supports the feasibility and safety of TPVI using the Melody valve in a variety of different anatomies and surgical prostheses.” They added that more data would be necessary to assess the risks and benefits of TPVI in the management of patients with postoperative RVOT dysfunction but said that the results of their study were “encouraging” for the use of the Melody valve in patients with failed bioprosthetic valves.
Gillespie told Cardiovascular News: “This retrospective report demonstrates that Melody in bioprosthetic valves is feasible, safe, and effective in the short term in patients with failed bioprosthetic valves, adding to the growing literature surrounding TPVI. The integration of percutaneous valve technologies into the life-long management plan of patients with postoperative RVOT dysfunction is likely to continue and expand. The early Melody in bioprosthetic valves results are promising, but longer term follow-up will be required to determine if this approach translates into improved heart health for our patients.”