New-onset atrial fibrillation in the ICU: a temporary disturbance or a lasting burden?

Introduction Atrial fibrillation (AF) is the most common arrhythmia observed in the intensive care unit (ICU) and is associated with increased in-hospital mortality. New onset atrial fibrillation (NOAF) has been associated with increased risk of both early and late stroke, but its association with other cardiovascular outcomes is less known. Objective The aims of this study were to compare the incidence of a composite endpoint—defined as all-cause mortality or unplanned cardiovascular hospitalization—between patients with and without new-onset atrial fibrillation and to determine whether new-onset atrial fibrillation was an independent predictor of 90-day mortality. Methods This was a retrospective, observational, single-center study which included ICU patients admitted between January 2020 and June 2022. Patients were categorized into two groups: those who developed new-onset atrial fibrillation (NOAF) and controls (No NOAF). Clinical and demographic variables were collected. Survival analyses were conducted using Kaplan–Meier and multivariate Cox regression methods. Results We included 240 patients, 160 with NOAF and 80 controls. The baseline demographic and clinical characteristics of these patients are in table 1. Among patients with NOAF, 67% had hypertension, 35% diabetes, and 15% a history of heart failure. The first-line strategy for managing NOAF was rhythm control (85%), observation (7.5%) or rate control (7.5%). At discharge, 29% of the patients were on anticoagulation therapy. After a mean follow up of 19.5 months, the composite of endpoint occurred in 42 patients in the NOAF group and 9 patients in the control group and this difference was statistically significant (p value= 0-012, log Rank test)- Graph 1. The multivariable Cox regression analysis included age, sex, previous hypertension, diabetes, hyperlipidemia, obesity, smoking and creatinine at admission and showed that NOAF was an independent predictor of death at 90 days (HR= 3.99, 95% CI- 1.19– 13.30; p = 0,024)- Graph 2. Conclusion NOAF was common among hospitalized patients and was associated with a significantly higher risk of adverse outcomes during follow-up. After adjustment for major clinical and demographic variables, NOAF remained an independent predictor of 90-day mortality. These findings highlight the importance of early recognition and appropriate management of NOAF to improve patient prognosis.