Pragmatic Randomized Clinical Trial Comparing Rectilinear Biphasic Waveform and Biphasic Truncated Exponential Waveform Shocks for Cardioversion of Atrial Fibrillation

Background No adequately powered prospective studies have compared the safety and efficacy of rectilinear biphasic waveform (RBW) shocks and biphasic truncated exponential (BTE) shocks for direct current cardioversion of atrial fibrillation. The study objective was to compare the efficacy of first shock direct current cardioversion from atrial fibrillation to normal sinus rhythm using a full‐output 200J RBW synchronized shock or a full‐output 360J BTE synchronized shock. Methods This investigator‐initiated, open‐label, unblinded, randomized controlled trial was performed at 3 hospitals in the Inova Health System between July 2023 and July 2024. Adult patients with symptomatic atrial fibrillation were randomized 1:1 to full‐output shock using a 200J RBW or 360J BTE shock waveform defibrillator. ECGs were performed before and 1 minute after each shock and adjudicated by a board‐certified electrophysiologist blinded to treatment assignment. Skin pads were positioned in an anterolateral placement in all patients. Successful direct current cardioversion was defined as normal sinus rhythm on 12‐lead ECG obtained ≥1 minute after shock delivery. Results A total of 546 unique patients were eligible for randomization, 270 patients were randomized to a 200J RBW shock and 276 patients to a 360J BTE shock. Normal sinus rhythm ≥1 minute after first shock delivery occurred in 223/270 (82.6%) patients randomized to 200J RBW shock and in 233/276 (84.4%) patients randomized to 360J BTE shock ( P =0.565). Overall, there were no significant differences in the frequency of attaining normal sinus rhythm after multiple direct current cardioversion shocks or safety events between patients randomized to 200J RBW or 360J BTE shocks. Conclusions We observed no difference in safety or efficacy between full‐output RBW or BTE shocks for atrial fibrillation cardioversion. Registration URL: https://clinicaltrials.gov ; Unique Identifier: NCT05992623.