Beta-blockers vs amiodarone in management of new onset atrial fibrillation in patients receiving critical care services: an analysis from a global federated research network

Background and objectives New onset atrial fibrillation (NOAF) is common in critically ill patients and is associated with increased adverse outcomes such as death, stroke, and myocardial infarction. While beta-blockers and amiodarone are both commonly used in the management of NOAF, there remains a need to determine whether these treatment strategies differ in terms of clinical benefits. Methods The TriNetX Global Collaborative Network was used to define two cohorts of patients who developed NOAF within 2 weeks of receiving critical care services and were treated with either beta-blockers or amiodarone, excluding patients with concomitant calcium channel blocker or digoxin treatment and prior beta-blocker use in the past 3 months. The primary outcome was all-cause mortality at 30 and 90 days. Analyses were performed before and after propensity score matching (PSM). Results Before PSM, the beta-blocker group (N=2841, age=71.9 ± 13.1) was older with fewer comorbidities, including hypertension, ischemic heart disease, and heart failure, when compared to the amiodarone group (N=610, age=69.8 ± 12.5). After PSM (matched N=577), patients in the beta-blocker group had a lower risk of 30-day (HR: 0.47, 95% CI: 0.32, 0.69) and 90-day all-cause mortality (HR: 0.60, 95% CI: 0.43, 0.83). Subgroup analyses were mainly consistent with the primary findings. Conclusion Beta-blocker therapy was associated with significantly lower 30-day and 90-day mortality compared with amiodarone in patients receiving critical care services who subsequently developed NOAF. However, the lack of a surrogate for acute disease severity limits interpretation of observed associations. Prospective randomised controlled trials are warranted to better define the optimal therapeutic strategy for patients who develop NOAF in the critical care setting.