Transcatheter melody valve placement in large diameter bioprostheses and conduits: What is the optimal "Landing zone"?

OBJECTIVES: This study sought to elucidate the optimal bioprosthetic valve (BPV) size prior to Melody valve implantation. BACKGROUND: BPVs provide an ideal "landing zone" for future Melody valve insertion. To guide surgical choice of BPV size, it is important to understand which BPV size can serve consistently as substrates for Melody valve placements. METHODS: A database of all patients who underwent Melody implantation at UCLA or Kaiser Permanente Los Angeles from 2010 to 2014 was analyzed retrospectively. Patients with an existing BPV were stratified into those with a valve diameter of ≥27 mm or <27 mm. RESULTS: One hundred and sixty patients underwent catheterization with the intention to implant a Melody valve. Melody valve implantation was performed in the pulmonary position in 52 patients with prior BPVs. The immediate procedural success rate was 100%. Immediately post-Melody, the right ventricular to pulmonary artery gradient was significantly higher in the <27 mm group compared to the ≥27 mm group (14.3±3 vs. 8.6±6.8, P=0.006). There was a significantly shorter time from prior valve replacement to Melody implantation in the <27 mm group. There was one patient in whom transcatheter pulmonary valve implantation was aborted due to inadequate landing zone in the <27 mm group, and no patients in the ≥27 mm group (P=NS). CONCLUSIONS: The results of this study indicate that 27 and 29 mm BPV provide a superior landing zone for Melody valve implantation with excellent immediate and intermediate term hemodynamic results when compared to smaller BPVs less than 27 mm.