SAT-597 The Mortality Enigma: Outcomes in Patients with Type 1 Diabetes Presenting with Atrial Fibrillation

Abstract Disclosure: S. Dinh: None. N. Sandhu: None. S. Mishra: None. Type 1 diabetes (T1D) is a chronic autoimmune disease that results in the destruction of insulin-secreting pancreatic beta-cells. Its early onset results in longer exposure to hyperglycemia and an increased risk of cardiovascular disease, the leading cause of death in patients with T1D. While the microvascular and macrovascular consequences of diabetes and hyperglycemia are well established and studied, majority of research focuses on the association between cardiovascular disease in patients with type 2 diabetes. Our study explores the clinical outcomes of patients with the less prevalent T1D and atrial fibrillation (AF). Patients with the primary diagnosis of AF were identified using the 2021 National Inpatient Sample and stratified based on the presence of T1D. The relationship between outcomes in patients with a history of T1D who were hospitalized for a primary diagnosis of AF was analyzed using multivariate regression analysis, adjusting for potential confounding variables. The threshold for statistical significance was set at a 2-tailed p-value of 0.05. In 2021, 369,399 adults were admitted with the primary diagnosis of AF. Of these, 49,444 had a concurrent diagnosis of T1D (13.4%). The mean age in the diabetes group was 70.8 years. Most patients in this group were male (52.3%), White (78.4%), had Medicare insurance (72.1%), and were admitted to urban teaching hospitals (49.1%). After adjusting for factors such as age, gender, insurance, income level, Charleston comorbidity index, location, and teaching status, there was decreased in-hospital mortality for patients admitted with AF who had concurrent T1D (aOR 0.64, 95% CI 0.48-0.84). This group also had decreased odds of vasopressor use (aOR 0.72, 95% CI 0.52-0.99), mechanical ventilation (aOR 0.72, 95% CI 0.55-0.96), and renal replacement therapy (aOR 0.09, 95% CI 0.05-0.15). Additionally, the African American population was found to have higher odds of mortality (aOR 1.34, 95% CI 1.03 - 1.74) and mechanical ventilation (aOR 1.79, 95% CI 1.41 - 2.29) compared to other groups. T1DM and AF are co-existing conditions that have been shown to have high mortality. However, our study shows that patients with T1DM who are hospitalized for AF may have better outcomes compared to those without T1DM. We speculate that the unexpected outcome difference could be a reflection of technology advancements like continuous glucose monitoring and automated insulin delivery systems for tight glycemic control. It also highlights racial disparities that providers should be aware of. Our study’s limitations, however, include potential misclassification bias with under or over-coding, inability to account for longer-term outcomes such as readmission, and other unaccounted confounding variables. Presentation: Saturday, July 12, 2025