Atrial fibrillation in COVID-19 patients admitted to an intensive care unit: prevalence and prognosis
Authors: Lopes V , Baptista J P , Moreira N , Goncalves L 
Published: October 2022

Abstract

Background
The association between atrial fibrillation (AF) and prognosis has been studied in non-COVID-19 patients, but few studies reflect the reality of critically ill COVID-19 patients admitted to a general intensive care unit (ICU).

Purpose
This study sought to investigate the relationship between previous and new-onset AF in COVID-19 patients admitted to an ICU and prognosis.

Methods
We retrospectively analyzed patients consecutively admitted to an ICU with COVID-19 and followed them for a median period of 7 months. Patients admitted due to trauma or emergent surgery were excluded from the analysis. Three groups were identified: without AF (G1), with prior history of AF (G2), and with new-onset AF (G3). Groups were compared, with special interest regarding ICU mortality, duration of mechanical ventilation, length of hospitalization, major adverse cardiac events (MACE), and re-hospitalization. MACE was defined as all-cause ICU mortality, new-onset heart failure, acute coronary syndrome, ventricular arrhythmias, pulmonary embolism, myocarditis, and stroke (ischemic or hemorrhagic).

Results
A total of 297 patients was included in the analysis: without AF (248 patients, 83.5%), with prior history of AF (15 patients, 5.1%), and with new-onset AF (34 patients, 11.4%). Median age was 62 (IQR 17) years, and most patients were male (198 patients, 66.7%).
Patients with a prior history of AF were older [median (IQR), G1 60 (16), G2 71 (12), G3 67 (15) years, p=0.001], were more likely to have a history of coronary artery disease (G1 4.9%, G2 26.7%, G3 11.8%, p=0.002), and history of heart failure (G1 6.5%, G2 33.3%, G3 17.6%, p&lt;0.001). Patients with new-onset AF had a longer duration of mechanical ventilation [median (IQR), G1 9 (13), G2 11 (16), G3 18 (12) days, p&lt;0.001), longer ICU length of stay [median (IQR), G1 12 (10), G2 13 (12), G3 19 (15), p=0.001], higher ICU mortality rate (G1 27.0%, G2 33.3%, G3 58.8%, p=0.001), and higher rate of MACE (G1 31.9%, G2 33.3%, G3 70.6%, p&lt;0.001), compared to the other groups. There were no differences regarding sex distribution, other baseline comorbidities, need for invasive mechanical ventilation, vasopressor use, and re-hospitalization rates among groups. Most AF patients were treated with beta-blockers (39.6%) and amiodarone (77.1%), but only 68.8% of patients received anticoagulation (G2 92.9%, G3 58.8%), which may reflect that physicians underestimate the prognosis of new-onset AF.
In multivariate analysis, new-onset AF (OR 3.07, 95% CI 1.42–6.67, p=0.005) and older age (OR 1.07, 95% CI 1.04–1.09, p&lt;0.001) remained independent predictors of ICU mortality. Main results are presented in Table 1. Kaplan-Meier survival curves are presented in Figure 1.

Conclusion(s)
This study shows that critically ill COVID-19 patients with AF present a worse prognosis compared to patients without AF, and new-onset AF is an independent predictor of ICU mortality and MACE.

Funding Acknowledgement
Type of funding sources: None.