Study Design & Population: The research was a two-center, prospective, controlled parallel-group, double-blind trial involving 209 septic shock patients who had new-onset supraventricular arrhythmia and a left ventricular ejection fraction above 35%. Patients were randomized to receive either intravenous propafenone (70 mg bolus followed by 400–840 mg/24 h) or amiodarone (300 mg bolus followed by 600–1800 mg/24 h).
Main Findings: The primary outcomes focused on the proportion of patients in sinus rhythm 24 hours post-infusion, time to the first sinus rhythm restoration, and arrhythmia recurrence rates. No significant difference was observed in 24-hour sinus rhythm rates between the propafenone (72.8%) and amiodarone (67.3%) groups (p=0.4). Time to the first rhythm restoration was significantly shorter for the propafenone group (median 3.7 hours) compared to the amiodarone group (median 7.3 hours, p=0.02). Recurrence of arrhythmia was notably lower in the propafenone group (52%) than in the amiodarone group (76%, p<0.001). In the subgroup of patients with a dilated left atrium, amiodarone appeared to be more effective.
Implications & Limitations: The study suggests that while propafenone doesn’t offer better rhythm control at 24 hours compared to amiodarone, it does provide faster cardioversion and fewer arrhythmia recurrences, especially in patients with a non-dilated left atrium. No significant differences were observed in clinical outcomes, such as ICU or long-term mortality, between propafenone and amiodarone in the trial. Limitations include potential underpowering of the study and the inability to fully account for the impact of multiple covariates involved in the complex therapy of septic shock.
Commentary on Twitter:
Propafenone💉70 mg bolus+ 400-840 mg/24h vs amiodarone💉300 mg + by 600-1800 mg/24h for SVA in septic shock, RCT
🫀propafenone not better for rhythm control at 24h but excellent hemodynamic safety profile, cardioverting faster & fewer recurrences#FOAMCc
— Intensive Care Medicine (@yourICM) September 13, 2023