Use and performance of the Melody Transcatheter Pulmonary Valve in native and postsurgical, nonconduit right ventricular outflow tracts.

BACKGROUND

Melody Transcatheter Pulmonary Valve (TPV) replacement therapy represents an important advance in congenital cardiovascular interventions. The off-label extension of the Melody TPV to patients with nonconduit outflow tracts (right ventricular outflow tract [RVOT]) has the potential to vastly expand the population of patients eligible to benefit from nonsurgical restoration of RVOT function. However, knowledge on the performance of the Melody TPV in this setting is limited.

METHODS AND RESULTS

This is a multicenter, retrospective review of the Melody TPV when placed in nonconduit RVOTs, in which at least a portion of the circumference was composed of native tissue. Five centers contributed data on 31 patients. The median age at implantation was 24 years (range, 7-66). At a median follow-up of 15 months, all patients were alive. No patient had greater than mild TPV insufficiency, and the median maximum instantaneous gradients across the RVOT was 23 mm Hg. Stent fracture occurred in 32%. Eight patients developed more than mild TPV obstruction, of whom 6 were associated with identified stent fracture. Three patients developed blood stream infections. There were 5 reinterventions in 3 patients, including 3 repeat TPV implantations and 2 TPV explantations.

CONCLUSIONS

Melody TPV implantation is feasible in selected patients with RVOTs comprised solely or predominantly native tissue and has the potential to expand the population of patients eligible to benefit from nonsurgical restoration of RVOT function. In early follow-up, valve competency seems preserved. The dominant mechanism of valve dysfunction seems to be related to stent fracture with recurrent obstruction. Additional data are necessary to better understand how to safely expand TPV therapy to this population.