A prospective 5-year study of the frequency of arrhythmias during serial exercise testing and clinical follow-up after Melody valve implant

BACKGROUND Although percutaneous Melody valve implant has become an accepted alternative to surgical pulmonary valve replacement in patients with congenital heart disease, the benefit regarding frequency and severity of arrhythmias remains undefined. OBJECTIVE The purpose of this study was to evaluate the impact of Melody valve implant on the type and frequency of arrhythmias during cardiopulmonary exercise testing (CPET) and subsequent clinical outcome. METHODS As part of the phase I Melody valve clinical trial, 136 patients with congenital heart disease underwent prospective serial evaluation including CPET before implant, 6 months after implant, and annually thereafter for 5 years. Arrhythmias were defined as premature ventricular complexes (PVCs) and supraventricular or ventricular tachycardia (VT). RESULTS Before Melody implant, PVCs occurred in 55 patients (400%) and nonsustained ventricular tachycardia (NSVT) in 1 patient during CPET. Median age at valve implantation was 19.0 years (range 7-53 years). During median follow-up of 4.9 years (range 0.8-7.3 years), there was no significant change in the proportion of patients with PVCs during CPET at any follow-up interval (40%-45%). However, postimplant, NSVT occurred in 18 patients, including 8 during CPET. Diagnoses in the patients with NSVT were tetralogy of Fallot (11), transposition (2), and post-Ross procedure (5). Improved hemodynamic status was not associated with resolution or prevention of arrhythmias. CONCLUSION Despite improvement in hemodynamics, Melody valve implant was not associated with resolution or prevention of arrhythmias during CPET. PVCs or VT may be related to pathologic hypertrophy, fibrosis, dilation, or possible mechanical effects of the Melody device. (C) 2016 Heart Rhythm Society. All rights reserved.