New-onset AF in critically ill septic patients had a higher incidence of rapid ventricular rate (90.7% vs 72.4%) and greater return to normal sinus rhythm (79.6% vs 46.1%) than pre-existing AF.
Does new-onset atrial fibrillation compared to pre-existing atrial fibrillation affect the incidence of rapid ventricular rate in critically ill septic patients?
In critically ill septic patients, new-onset atrial fibrillation is associated with a higher incidence of rapid ventricular rate and greater severity of critical illness compared to pre-existing atrial fibrillation, though they are more likely to return to normal sinus rhythm.
Introduction: New onset atrial fibrillation (NOAF) arises from stressors of critical illness, but its progression and clinical impact compared to pre-existing atrial fibrillation (PEAF) remain unclear. This study aimed to evaluate outcomes in critically ill septic patients with NOAF and PEAF. Methods: This single-center retrospective cohort study evaluated adult septic patients who experienced AF during their index admission to the surgical, medical, or mixed ICUs. The primary outcome was the incidence of AF with rapid ventricular rate (RVR, heart rate ≥ 110 beats per minute (bpm) for ≥ 15 minutes. Secondary outcomes included highest heart rate (HR) within 48 hours of AF onset, achievement of rate control (HR < 110 bpm for ≥ 6 hours), return to normal sinus rhythm (NSR) for ≥ 24 hours, AF management strategies, major bleeding or ischemic events, therapeutic anticoagulation initiation, and AF recurrence. Statistical analyses were conducted via Fisher’s exact test for nominal data, T-test for normally distributed continuous data, and Mann-Whitney U test for non-normally distributed continuous data. Results: Fifty-four NOAF patients and 76 PEAF patients were included. Patients had similar demographics (median age of 69 years, 60% male) and past medical history. NOAF patients experienced a longer time to AF onset (19 vs 7.5 hours, p=0.011) and a greater incidence of RVR (90.7% vs 72.4%, p=0.014). AF treatment was administered to 88.8% of NOAF patients and 73.7% of PEAF patients (p=0.033) and 79.6% and 46.1%, respectively, experienced a return to NSR (p< 0.001). In the NOAF group, there were higher rates of renal replacement therapy (25.9% vs 7.9%, p=0.007), more mechanical ventilation (46.3% vs 15.3%, p< 0.001), and increased vasopressor rates (0.21 vs 0.06 mcg/kg/minute norepinephrine dose equivalents, p=0.02) at AF onset despite similar SOFA scores (6 4-10 vs 5 4-7, p=0.13). Therapeutic anticoagulation initiation, major bleeding events, and ischemic events were similar between groups. Conclusions: NOAF patients had a higher incidence of RVR but also showed signs of greater critical illness. These patients were also more likely to receive AF treatment and experience a return to NSR. Additional studies are needed to clarify optimal management and outcomes for NOAF and PEAF in critically ill patients.
Harding et al. (2026) studied this question. New-onset AF in critically ill septic patients had a higher incidence of rapid ventricular rate (90.7% vs 72.4%) and greater return to normal sinus rhythm (79.6% vs 46.1%) than pre-existing AF.