RADAR: A Multicenter Food and Drug Administration Investigational Device Exemption Clinical Trial of Persistent Atrial Fibrillation.

BACKGROUND: Pulmonary vein isolation is insufficient to treat all patients with persistent atrial fibrillation (AF), and effective adjunctive ablation strategies are needed. Ablation of AF drivers holds promise, but current technologies to identify drivers are limited by spatial resolution. In a single-arm, first-in-human, investigator-initiated Food and Drug Administration Investigational Device Exemption study, we used a novel system for real-time, high-resolution identification of AF drivers in persistent AF. METHODS: Patients with persistent or long-standing persistent AF underwent ablation using the RADAR (Real-Time Electrogram Analysis for Drivers of Atrial Fibrillation) system in conjunction with a standard electroanatomical mapping system. After pulmonary vein isolation, electrogram and spatial information was streamed to the RADAR system and analyzed to identify driver domains to target for ablation. RESULTS: Across 4 centers, 64 subjects were enrolled: 73% male, age, 64.7±9.5 years; body mass index, 31.7±6.0 kg/m2; left atrium size, 54±10 mm, with persistent/long-standing persistent AF in 53 (83%)/11 (17%), prior AF ablation (re-do group) in 26 (41%). After 12.6±0.8 months follow-up, 68% remained AF-free off all antiarrhythmics; 74% remained AF-free and 66% remained AF/atrial tachycardia/atrial flutter-free on or off AADs (antiarrhythmic drugs). AF terminated with ablation in 35 patients (55%) overall and in 23/38 (61%) of de novo ablation patients. For patients with AF termination during ablation, 82% remained AF-free and 74% AF/atrial tachycardia/atrial flutter-free during follow-up on or off AADs. Patients undergoing first-time ablation generally had higher rates of freedom from AF than the re-do group. CONCLUSIONS: This novel technology for panoramic mapping of AF drivers showed promising results in a persistent/long-standing persistent AF population. These data provide the scientific basis for a randomized trial. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03263702; IDE#G170049.