Seven-Year Outcomes Published From IDE Trial of Medtronic's Melody TPV

May 14, 2015—John P. Cheatham, MD, et al published results from the United States Melody transcatheter pulmonary valve (TPV; Medtronic, plc) investigational device exemption (IDE) trial, including clinical and hemodynamic outcomes up to 7 years after the TPV replacement (TPVR) procedure. The findings are available online ahead of print in Circulation. 

The Melody TPV was first approved under a US Food and Drug Administration humanitarian device exemption in 2010. In February 2015, Medtronic announced that the Melody TPV received US Food and Drug Administration premarket approval based on accumulated data from the Melody United States IDE study and two other clinical studies, the Melody United States postapproval study and the Melody European and Canadian postmarket surveillance study, all of which followed a total of 310 patients implanted with Melody TPV. 

As summarized in Circulation, the IDE trial prospectively enrolled 171 pediatric and adult patients (median, 19 years) with right ventricular outflow tract (RVOT) conduit obstruction and/or pulmonary regurgitation (PR). The 148 patients who underwent TPVR were followed annually according to a standardized protocol. 

During a median follow-up of 4.5 years (0.4–7 years), 32 patients underwent RVOT reintervention for obstruction (n = 27, with stent fracture in 22), endocarditis (n = 3, two with stenosis and one with PR), or RV dysfunction (n = 2). Eleven patients had the TPV explanted as an initial or second reintervention. 

The investigators reported that 5-year freedom from reintervention and explantantation rates were 76% ± 4% and 92% ± 3%, respectively. A conduit prestent and lower discharge RVOT gradient were associated with longer freedom from reintervention. 

Additionally, in the 113 patients who were alive and reintervention-free, the follow-up gradient (median, 4.5 years after implantation) was unchanged from early post-TPVR, and all but one had mild or less PR. Almost all patients were in New York Heart Association class I or II. More severely impaired baseline spirometry was associated with lower likelihood of improvement in exercise function after TPVR, noted the investigators.

In Circulation, the investigators concluded that TPVR with the Melody device provided good hemodynamic and clinical outcomes up to 7 years after implantation, primary valve failure was rare, and the main cause of TPV dysfunction was stenosis related to stent fracture, which was uncommon once prestenting became more widely adopted.