Abstract 7379: Exploring the epidemiology, clinical outcomes, and healthcare burden of multiple myeloma patients with atrial fibrillation hospitalized for sepsis: a population-based study

Abstract Introduction: Multiple myeloma (MM) patients face a high risk of infection-related complications, and many also develop atrial fibrillation (AF), partly due to disease-driven inflammation and treatments like chemotherapy and immunotherapy. While AF is known to worsen outcomes in various cancers, its specific impact on MM patients with sepsis remains unclear. This study investigates how AF influences outcomes in MM patients hospitalized with sepsis, shedding light on an important yet underexplored aspect of their care. Methods: We identified adult patients with MM from the National Inpatient Sample who were admitted with the principal diagnosis of sepsis from 2018 to 2021, using ICD-10 codes. We divided the cohort based on the presence or absence of AF and applied complex sampling weights to ensure national representativeness. Our primary outcome was all-cause mortality, and we analyzed several secondary outcomes. We used multivariate regression models to evaluate outcome disparities between the groups, with statistical significance set at p < 0.05. Results: We identified 56, 970 adults with MM admitted with sepsis between 2018 and 2021, of whom 15, 565 (27.3%) had AF. The mortality rates were 14.0% for the entire cohort and 17.9% for the AF group. Patients with AF were older (74.7 vs. 69.0 years, p<0.001), had a higher proportion of male patients (63.2% vs.56.2%, p<0.001), and a higher proportion of white patients (71.5% vs. 59.6%, p<0.001). They also had a higher comorbidity burden (Charlson Comorbidity Index > 3: 89.8% vs. 79.2%, p<0.001). Patients with AF had higher odds of all-cause mortality with an adjusted odds ratio (aOR) of 1.60 (95% confidence interval [CI] 1.41-1.81). They had higher odds of respiratory failure (aOR 1.50, 95% CI 1.36-1.64), mechanical ventilation use (aOR 1.66, 95% CI 1.41-1.96), septic shock (aOR 1.60, 95% CI 1.45-1.78) vasopressor use (aOR 1.64, 95% CI 1.33-2.01), and renal replacement therapy use (aOR 1.69, 95% CI 1.43-2.01). Furthermore, they experienced longer hospital stays (8.6 vs. 7.8 days) with an adjusted incidence rate ratio (aIRR) of 1.14 (95% CI 1.09-1.19) and higher hospitalization charges ($110, 329 vs. $99, 756) with aIRR of 1.20 (95% CI 1.13-1.28). Conclusion: This study indicates that MM patients with sepsis and AF have worse outcomes, such as higher mortality, increased need for critical treatments (including mechanical ventilation, vasopressors, and renal replacement therapy), longer hospital stays, and higher medical expenses. These results highlight the necessity for careful and individualized management of MM patients with AF, especially when they develop sepsis. Citation Format: Adamsegd I. Gebremedhen, Abdu Mohammed, Mamdouh Souleymane, Yifang Song, Yonas Fetle, Mahmoud Abdallah, Muhammad O. Jamil. Exploring the epidemiology, clinical outcomes, and healthcare burden of multiple myeloma patients with atrial fibrillation hospitalized for sepsis: a population-based study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7379.