SAT-411 Gender-Based Differences in Mortality and Cardiac Complications Among Patients Hospitalized for Thyroid Storm: A Nationwide Analysis

Abstract Disclosure: S. Prasad: None. M. Singh: None. S. Balasubramanian: None. M. Souleymane: None. D. Thor: None. S. Ball: None. R. Viswanathan: None. R. Patel: None. M. Lee: None. G. Das: None. A. Jala: None. A. Faizal: None. Y. Wang: None. Introduction: Myxedema Coma (MC) is a rare endocrine emergency characterized by severe hypothyroidism and cardiovascular instability. While arrhythmias are commonly associated with MC, their prevalence, risk factors, and clinical impact remain unclear. This study examines the burden and predictors of cardiac arrhythmias in MC hospitalizations. Objective: To evaluate the prevalence and predictors of cardiac arrhythmias in MC using the National Inpatient Sample(NIS) database.Methods:A retrospective cohort study of the NIS from 2015-2022 identified MC hospitalizations using ICD-10 codes. Outcomes included bradycardia, heart block (HB), atrial fibrillation/flutter (Afib/flutter), ventricular fibrillation/tachycardia (Vfib/Vtach), cardiac arrest, transcutaneous or transvenous pacing, cardiogenic shock, and vasopressor use. Multivariate logistic regression identified predictors, adjusting for demographics and comorbidities. Results:Among 8,385 MC hospitalizations, 32.3% had at least one arrhythmia. 22.6% had bradycardia, 3.89% had HB (first-degree HB most common, 2.33%), and 7.63% had Afib/flutter. 2.33% had Vfib/Vtach, 3.8% experienced cardiac arrest, and 3.4% had cardiogenic shock. Hypotension occurred in 19.6%, with 5.3% requiring vasopressors, while 0.9% needed pacing.Older age (aOR 1.3, p=0.024) and chronic kidney disease (CKD) (aOR 1.32, p=0.044) were associated with bradyarrhythmias. Afib/flutter predictors included coronary artery disease (CAD) (aOR 1.66, p=0.017), Charlson Comorbidity Index >2 (aOR 1.85, p<0.05), and age >65 (aOR 4.41, p<0.005). Gender and race were not predictors. Arrhythmias were not independently associated with mortality. Conclusion: Cardiac arrhythmias are common in MC, affecting nearly one-third of hospitalized patients, with bradyarrhythmias and Afib/flutter being the most prevalent. Advanced age, CKD, and CAD were significant predictors, while gender and race were not. Despite their high prevalence, arrhythmias were not independent predictors of mortality, suggesting other factors may play a larger role in outcomes. These findings highlight the need for vigilant cardiovascular monitoring and further research to refine management strategies in MC. Presentation: Saturday, July 12, 2025