The outcomes of patients with septic shock treated with propafenone compared to amiodarone for supraventricular arrhythmias are related to end-systolic left atrial volume.

AIMS: A recently published trial has shown no differences in outcomes between patients with new-onset supraventricular arrhythmia (SVA) in septic shock treated with either propafenone or amiodarone. However, these outcome data have not been evaluated in relation to the presence or absence of a dilated left atrium (LA). METHODS AND RESULTS: Patients with SVA and a left ventricular ejection fraction ≥ 35% were randomized to receive intravenous propafenone (70 mg bolus followed by 400-840 mg/24 h) or amiodarone (300 mg bolus followed by 600-1800 mg/24 h). They were divided into groups based on whether their end-systolic left atrial volume (LAVI) was ≥40 mL/m². The subgroup outcomes assessed were survival at ICU discharge, 1 month, 3 months, 6 months, and 12 months. Propafenone cardioverted earlier (P = 0.009) and with fewer recurrences (P = 0.001) in the patients without LA enlargement (n = 133). Patients with LAVI < 40 mL/m2 demonstrated a mortality benefit of propafenone over the follow-up of 1 year [Cox regression, hazard ratio (HR) 0.6 (95% CI 0.4; 0.9), P = 0.014]. Patients with dilated LA (n = 37) achieved rhythm control earlier in amiodarone (P = 0.05) with similar rates of recurrences (P = 0.5) compared to propafenone. The outcomes for patients with LAVI ≥ 40 mL/m2 were less favourable with propafenone compared to amiodarone at 1 month [HR 3.6 (95% CI 1.03; 12.5), P = 0.045]; however, it did not reach statistical significance at 1 year [HR 1.9 (95% CI 0.8; 4.4), P = 0.138]. CONCLUSION: Patients with non-dilated LA who achieved rhythm control with propafenone in the setting of septic shock had better short-term and long-term outcomes than those treated with amiodarone, which seemed to be more effective in patients with LAVI ≥ 40 mL/m². TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03029169, registered on 24 January 2017.

Propafenone versus amiodarone for supraventricular arrhythmias in septic shock: a randomised controlled trial.

PURPOSE: Acute onset supraventricular arrhythmias can contribute to haemodynamic compromise in septic shock. Both amiodarone and propafenone are available interventions, but their clinical effects have not yet been directly compared. METHODS: In this two-centre, prospective controlled parallel group double blind trial we recruited 209 septic shock patients with new-onset arrhythmia and a left ventricular ejection fraction above 35%. The patients were randomised in a 1:1 ratio 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). The primary outcomes were the proportion of patients who had sinus rhythm 24 h after the start of the infusion, time to restoration of the first sinus rhythm and the proportion of patients with arrhythmia recurrence. RESULTS: Out of 209 randomized patients, 200 (96%) received the study drug. After 24 h, 77 (72.8%) and 71 (67.3%) were in sinus rhythm (p = 0.4), restored after a median of 3.7 h (95% CI 2.3-6.8) and 7.3 h (95% CI 5-11), p = 0.02, with propafenone and amiodarone, respectively. The arrhythmia recurred in 54 (52%) patients treated with propafenone and in 80 (76%) with amiodarone, p < 0.001. Patients with a dilated left atrium had better rhythm control with amiodarone (6.4 h (95% CI 3.5; 14.1) until cardioversion vs 18 h (95% CI 2.8; 24.7) in propafenone, p = 0.05). CONCLUSION: Propafenone does not provide better rhythm control at 24 h yet offers faster cardioversion with fewer arrhythmia recurrences than with amiodarone, especially in patients with a non-dilated left atrium. No differences between propafenone and amiodarone on the prespecified short- and long-term outcomes were observed.