Comparative Effectiveness of Amiodarone Versus Lidocaine as Antiarrhythmic Therapy for Cardiac Arrest with Shockable Rhythms: A Systematic Review and Meta-Analysis.

Background: Amiodarone and lidocaine are antiarrhythmic agents recommended for advanced cardiac life support in shockable ventricular arrhythmias during cardiac arrest, yet their comparative effectiveness in in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA) remains uncertain. Methods: From 930 records identified in PubMed, ScienceDirect, Embase, and Cochrane Library, 14 studies were included. Outcomes were analyzed using random-effects meta-analysis in R with IHCA and OHCA subgroup analyses. Bayesian meta-analysis using the bayesmeta package assessed result credibility. Results: Amiodarone did not improve return of spontaneous circulation (R0SC) compared with lidocaine (Risk ratio (RR) 0.96, p = 0.40). In IHCA, amiodarone was associated with lower survival to hospital discharge (RR 0.88, p < 0.0001), lower 24 h survival (RR 0.93, p < 0.0001), worse neurological recovery (RR 0.83, p < 0.0001), and longer arrest duration (Mean difference (MD) 7.46 min, p = 0.002). Termination of shockable rhythms favored lidocaine only after sensitivity analysis (RR 0.51, p = 0.02). In OHCA, amiodarone did not improve survival to discharge (RR 0.93, p = 0.44), while return of spontaneous circulation favored lidocaine after sensitivity analysis (RR 0.88, p = 0.002). No consistent benefit was observed across outcomes. Bayesian analysis showed overlapping credible intervals and low probabilities of benefit, indicating no clear superiority. Conclusions: No survival difference was observed between amiodarone and lidocaine arrest. Although lidocaine showed more favorable in-hospital outcomes, long-term survival was similar, suggesting agents may be selected based on availability and practice.