Effectiveness of amiodarone versus digitalis for heart rate control in critically ill patients with new-onset atrial fibrillation.

New-onset of atrial fibrillation (NOAF) in critically ill patients is the most common acute cardiac dysrhythmia, but evidence-based data regarding treatment strategies are scarce. In this retrospective monocentric study, we compared effectiveness of amiodarone versus digitalis for heart rate control in critically ill patients with new-onset of atrial fibrillation. We identified a total of 209 patients for the main analysis. Amiodarone as compared to digitalis was associated with a clinically relevant faster time to heart rate control < 110 bpm (2 h (IQR: 1 h to 6 h) versus 4 h (2 h to 12 h); p = 0.003) and longer durations of sinus rhythm during the first 24 h of treatment (6 h (IQR: 6 h to 22 h) versus 0 h (IQR: 0 h to 16 h); p < 0.001). However, more bradycardic episodes occurred in association with amiodarone than with digitalis (7.7% versus 3.4%; p = 0.019). Use of amiodarone was associated with an increase of noradrenalin infusion rate compared to digitalis (23.9% versus 12.0%; p = 0.019). Within the tertile of patients with the highest CRP measurements, amiodarone treated patients presented with a higher decrease in heart rate than digoxin treated patients. Clinical trials comparing different NOAF treatment strategies are much needed and should report on concomitant sympathetic activity and inflammatory status.