Abstract WP233: Occurrence and Prognostic Significance of Atrial Fibrillation in Patients with Aneurysmal Subarachnoid Hemorrhage in the United States

Introduction: Although atrial fibrillation has been identified in patients with aneurysmal subarachnoid hemorrhage (aSAH), the effect of concurrent occurrence on outcomes is not well understood. Both atrial fibrillation and aSAH are associated with higher risk of cerebral ischemic events and may pose restriction on use of anticoagulation. Methods: We analyzed the nationally representative data from the National Inpatient Sample (NIS) between 2016 and 2022. We compared the rates of in-hospital mortality, routine discharge (without palliative care), poor outcome defined by NIS-SAH measure, length of stay, and hospitalization cost in SAH patients with and without atrial fibrillation. Logistic and linear regression analyses were used to adjust for potential confounders. Results: A total of 4670 (7.8%) patients had atrial fibrillation among 59,265 patients with aSAH. Minimal decrease in atrial fibrillation prevalence was observed (7.6% in 2016 to 7.2% in 2021, p trend =0.027). Patients with atrial fibrillation were more likely to receive endovascular treatment, hydrocephalus treatment, palliative care, and mechanical ventilation. No significant difference in rates of cerebral infarction was observed. After adjustment for age, gender, and aneurysmal treatment (surgical versus endovascular), atrial fibrillation was associated with higher rates of in-hospital mortality (19.9% vs. 12.7%; Odds Ratio [OR] –1.23, 95% CI 1.03-1.48 p=0.025) and poor outcome (90.5% versus 80.7%; [OR] 1.53, 95% CI 1.21-1.94, p<0.001), lower rates of routine discharge (OR 0.56, 95% CI 0.46-0.68, p<0.001), and higher length of hospitalization (median 18 days [range 12 to 25] vs. 16 days [11 to 23]; coefficient 1.46, 95% CI 0.53 to 2.39) and hospitalization cost (median USD 94,053 vs. 83,536; coefficient 12,064, 95% CI 7,611 to 16,518). Conclusion: Although infrequent, atrial fibrillation was associated with higher rates of in-hospital mortality and poor outcome in aSAH patients. These findings highlight the need for standardizing management protocols to improve outcomes in this patient population.