A Multicenter Study Assessing the Optimal Anticoagulation Strategies in COVID-19 Critically III Patients with New-Onset Atrial Fibrillation: Balancing Effectiveness and Safety

Purpose: To evaluate the effectiveness and safety of anticoagulation regimens in COVID-19 critically ill patients with new-onset Atrial fibrillation (Afib) during their intensive care unit (ICU) stays. Methods: A multicenter, retrospective cohort study included critically ill patients with COVID-19 admitted to the ICUs. Patients with new-onset Afib were categorized into two groups based on anticoagulation doses (Prophylaxis vs Treatment). The primary outcome was the bleeding rate; other outcomes were considered secondary. Logistic, negative binomial regression, and Cox proportional hazards regression analyses were applied as appropriate after PS matching. Results: A total of 107 patients were eligible. After PS matching (1:1 ratio), 56 patients were included in the final analysis. A higher odd for major and minor bleeding were observed in the patients who received treatment doses of anticoagulation; however, it did not reach the statistically significant (OR 1.46; 95% CI 0.29, 7.42; P=0.65 and OR 2.04; 95% CI 0.17, 24.3; P=0.57, respectively). The hospital length of stay and in-hospital mortality showed no differences between the two groups (beta coefficient -0.00; CI -0.38, 0.37; P=0.99 and HR 1.12, 95% CI 0.58-2.14; p = 0.74, respectively). On the other hand, patients in the treatment group had a statistically significant higher requirement of RBCs transfusion than patients who received a prophylaxis dose (beta coefficient 1.17; 95% CI 0.11, 2.22, P=0.03). Conclusion: The use of treatment anticoagulation doses in COVID-19 critically ill patients with new-onset Afib did not show better effectiveness over prophylactic anticoagulation doses; however, patients who received treatment anticoagulation doses had higher RBCs transfusion requirements. Our results must be cautious; thus, larger randomized interventional studies with a larger sample size are required to confirm our findings. Keywords: COVID-19, anticoagulation, prophylaxis, treatment dose, thrombosis, bleeding, atrial fibrillation, critically ill, mortality