MAGNETIC VT study: a prospective, multicenter, post-market randomized controlled trial comparing VT ablation outcomes using remote magnetic navigation-guided substrate mapping and ablation versus manual approach in a low LVEF population.

PURPOSE: Patients with ischemic cardiomyopathy (ICM) are prone to scar-related ventricular tachycardia (VT). The success of VT ablation depends on accurate arrhythmogenic substrate localization, followed by optimal delivery of energy provided by constant electrode-tissue contact. Current manual and remote magnetic navigation (RMN)-guided ablation strategies aim to identify a reentry circuit and to target a critical isthmus through activation and entrainment mapping during ongoing tachycardia. The MAGNETIC VT trial will assess if VT ablation using the Niobe™ ES magnetic navigation system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT and low ejection fraction. METHODS AND RESULTS: This is a randomized, single-blind, prospective, multicenter post-market study. A total of 386 subjects (193 per group) will be enrolled and randomized 1:1 between treatment with the Niobe ES system and treatment via a manual procedure at up to 20 sites. The study population will consist of patients with ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) of ≤35% and implantable cardioverter defibrillator (ICD) who have sustained monomorphic VT. The primary study endpoint is freedom from any recurrence of VT through 12 months. The secondary endpoints are acute success; freedom from any VT at 1 year in a large-scar subpopulation; procedure-related major adverse events; and mortality rate through 12-month follow-up. Follow-up will consist of visits at 3, 6, 9, and 12 months, all of which will include ICD interrogation. CONCLUSIONS: The MAGNETIC VT trial will help determine whether substrate-based ablation of VT with RMN has clinical advantages over manual catheter manipulation. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02637947.

Device closure of muscular ventricular septal defects using the Amplatzer muscular ventricular septal defect occluder: immediate and mid-term results of a U.S. registry.

OBJECTIVES: We sought to report the results of a U.S. registry of device closure of congenital muscular ventricular septal defects (VSDs) using the new Amplatzer mVSD occluder (AGA Medical Corp., Golden Valley, Minnesota). BACKGROUND: Muscular VSDs pose a significant surgical challenge with increased morbidity and mortality. METHODS: Data were prospectively collected from 83 procedures involving 75 patients who underwent an attempt of percutaneous (70 [93.3%] of 75) and/or perventricular (surgical) (6 [8.0%] of 75) device closure of hemodynamically significant muscular VSDs. The patients' median age was 1.4 years (range 0.1 to 54.1 years). Outcome parameters were procedural success, evidence of residual shunts on echocardiography, and occurrence of procedure-related complications. The median follow-up was 211 days (range 1 to 859 days). RESULTS: The median size of the primary VSD was 7 mm (range 3 to 16 mm) and in 34 of 78 (43.6%) procedures, patients had multiple VSDs (range 2 to 7). The device was implanted successfully in 72 of 83 (86.7%) procedures. In 17 of 83 (20.5%) procedures, multiple devices were implanted (range 2 to 3). Procedure-related major complications occurred in 8 of 75 (10.7%) patients. Device embolization occurred in two patients and cardiac perforation in one patient. There were two (2.7%) procedure-related deaths. The 24-h postprocedural complete closure rate was 47.2% (34 of 72 patients), increasing to 69.6% (32 of 46 patients) at 6 months and 92.3% (24 of 26 patients) at 12 months. Six patients underwent successful closure using the perventricular surgical (beating heart) approach, with complete closure at day 1 in three patients and trivial/small residual shunts in the remainder of the patients. CONCLUSIONS: The Amplatzer mVSD device (AGA Medical Corp.) offers excellent closure rates and low mortality when used to close congenital muscular VSDs. The device appears to be safe and effective.