Abstract 14045: The Incidence and Associated Risk Factors of New-onset Atrial Fibrillation in the Medical Intensive Care Unit

Introduction: New-onset AF (NOAF) in the medical ICU is associated with worse patient outcomes. The research on NOAF in this setting compared to that in the post-cardiothoracic and non-cardiac surgery patients is not as robust. For example, a 2019 literature review found that the reported incidence of NOAF in the medical ICU ranges between 1.7% and 43.9%. This retrospective single-center observational study examines the incidence and associated risk factors of this relatively understudied population. Methods: The total study population is comprised of 2682 consecutive patients with medical ICU stays in 2018. Post-operative patients as well as patients with preexisting AF were excluded. ICD-10 codes were used in conjunction with i2b2 to identify patients. Manual chart review confirmed those with NOAF during a 2018 ICU stay. These patients were compared with a control group comprised of 106 randomly-selected patients from the study population. Demographics and diagnoses were collected, along with length of stay (LOS), mortality at discharge and mortality after one year. Results: 90 patients of the 2682 patient cohort (3.4%) developed NOAF during their ICU stay. Patients with NOAF were more likely to be older (67.7 vs. 56.5 years), have hypertension (75.6% vs. 62.3%) and have peripheral vascular disease (41.1% vs. 26.4%) compared to the control group. More importantly, NOAF was associated with an increased LOS of 16.5 days relative to 9.6 days in the control group. No significant difference was found in mortality between the two groups. The results of this preliminary analysis are summarized in Table 1 . Conclusions: We found the incidence of NOAF in patients admitted to the medical ICU was 3.4%, and NOAF was associated with a significant increase in LOS. Upon completion of data extraction and multivariate analysis for the entire study population, we hope that this study will contribute to our understanding of the significance of NOAF in critically ill patients.