Implantation of the melody transcatheter pulmonary valve in patients with a dysfunctional right ventricular outflow tract conduit early results from the u.s. Clinical trial

Abstract

Objectives: This study was designed to evaluate the safety, procedural success, and short-term effectiveness of the Melody transcatheter pulmonary valve (Medtronic, Inc., Minneapolis, Minnesota) in patients with dysfunctional right ventricular outflow tract conduits.

Background: Conduit dysfunction has recently been treated with transcatheter pulmonary valve placement. There have been no prospective, multicenter trials evaluating this technology.

Methods: Standardized entry criteria, implantation, and follow-up protocols were used. Nonimplanting core laboratories were used to evaluate results.

Results: Between January 2007 and September 2007, 34 patients underwent catheterization for intended Melody valve implantation at 3 centers. Mean age was 19.4 +/- 7.7 years. Initial conduit Doppler mean gradient was 28.8 +/- 10.1 mm Hg, and 94% of patients had moderate or severe pulmonary regurgitation (PR). Implantation was successful in 29 of 30 attempts and not attempted in 4 patients. Procedural complications included conduit rupture requiring urgent surgery and device removal (n = 1), wide-complex tachycardia (n = 1), and distal pulmonary artery guidewire perforation (n = 1). Peak systolic conduit gradient fell acutely from 37.2 +/- 16.3 mm Hg to 17.3 +/- 7.3 mm Hg, and no patient had more than mild PR. There were no deaths or further device explants. At 6-month follow-up, conduit Doppler mean gradient was 22.4 +/- 8.1 mm Hg, and PR fraction by magnetic resonance imaging was significantly improved (3.3 +/- 3.6% vs. 27.6 +/- 13.3%, p < 0.0001). Stent fracture occurred in 8 of 29 implants; 3 of these were treated with a second Melody valve for recurrent stenosis later in follow-up.

Conclusions: Implantation of the Melody valve for right ventricular outflow tract conduit dysfunction can be performed by experienced operators at multiple centers, appears safe, and has encouraging acute and short-term outcomes.