Abstract 4139644: Unraveling the Impact of Giant Cell Myocarditis in Cardiogenic Shock: A Comprehensive Analysis of Incidence, Mortality, and Hospitalization Costs from the National Inpatient Sample (2016-2020)

Background: Giant Cell Myocarditis (GCM), a rare and aggressive inflammatory heart disease characterized by infiltration of the myocardium by multinucleated giant cells and extensive inflammation, represents a clinical conundrum, particularly in patients with cardiogenic shock (CS). Despite its rarity, GCM's devastating impact necessitates thorough investigation. To address this gap, our study harnesses comprehensive data from the National Inpatient Sample (NIS), aiming to unravel the incidence and mortality patterns of GCM in the context of CS. Methods: Utilizing data from the NIS spanning from 2016 to 2020, we identified admissions for CS. Diagnosis of GCM was defined with an ICD-10 CM code of I40.1 in patients who have had endomyocardial biopsy (captured using ICD-10 PCS codes of 02BK0ZX, 02BK3ZX, 02BK4ZX, 02BL0ZX, 02BL3ZX, 02BL4ZX, and 02BL4ZZ) during the index hospitalization. Survey weights were used to compute national estimates. Sociodemographic variables, medical comorbidities, procedures performed during the hospitalization, and outcomes of index hospitalizations were coded using corresponding ICD-10 codes. Descriptive statistics were used to summarize the study population. Results: Between 2016 and 2020, there were 114 admissions for GCM in the context of CS. The five-year incidence of GCM among CS admissions was 0.015%. The cohort's mean age was 48.4 years (SD 15.7), with males comprising 58.8% of the population. Racial and Ethnic composition included 69% Whites, 10% Blacks, and 8% Hispanics. Notably, 95.6% of these admissions occurred in urban teaching hospitals. Pulmonary artery catheterization for hemodynamic monitoring was employed in 23.7% of the cases. Temporary mechanical circulatory support devices were utilized in 56.1% of the admissions, including intra-aortic balloon pump in 28.9%, percutaneous ventricular assist devices in 8.8%, and extracorporeal membrane oxygenation in 21.9% of cases. Additionally, 36.9% of the patients required mechanical ventilation, and 34.8% underwent heart transplantation. The overall mortality rate was 23.7%. The median length of hospital stay was 24.6 days (IQR 16.5), and the median hospitalization cost was $955,128 (IQR $794,708). Conclusion: GCM complicating CS poses a formidable challenge with high mortality rates, length of stay, and cost of hospitalization despite intensive care interventions, emphasizing the urgency for advanced treatment modalities and tailored management approaches.