Clinical course after identification of new-onset atrial fibrillation in critically ill patients: The AFTER-ICU study

Abstract Purpose Epidemiological information is lacking after identification of new-onset atrial fibrillation (AF) in critically ill patients. This study aimed to describe the clinical course after the identification of new-onset AF. Materials and methods This prospective cohort study enrolled adult patients with new-onset AF in 32 Japanese ICUs during 2017–2018. We collected data on patient comorbidities, physiological information before and at the AF onset, interventions for AF, cardiac rhythm transition, adverse events and in-hospital death and stroke. Results We included 423 new-onset AF patients. At the AF onset, mean arterial pressure decreased and the heart rate increased. Eighty-four patients (20%) spontaneously restored sinus rhythm and 328 patients (78%) received various pharmacological interventions (rate-control drugs, 67%; rhythm-control drugs, 34%). Anticoagulants were administered in 173 patients (40%) and 13 patients (3%) experienced bleeding complications. Twenty-four patients (6%) were still in AF at 168 h after the onset (sustained AF 4%; recurrent AF 2%). The overall hospital mortality was 26% and the incidence of in-hospital stroke was 4.5%. Conclusions Although the proportion of patients with AF continued to decrease with various treatments, these patients had high risk of death. Further research to assess the management of new-onset AF in critically ill patients is warranted.