Sex Differences in Mortality and Treatment Utilization Across Cardiogenic Shock Phenotypes: A National Cohort Study

Abstract Background Cardiogenic shock (CS) is a heterogeneous syndrome with diverse etiologies, treatment pathways, and outcomes. Prior studies of sex differences in CS have largely focused on acute myocardial infarction-related CS or evaluated CS as a single entity. Whether sex-based differences in outcomes and treatment utilization vary across distinct CS phenotypes remains incompletely defined. Methods We performed a retrospective cohort study using the National Inpatient Sample, a nationally representative all-payer database of United States hospitalizations. Adult hospitalizations with CS were identified using ICD-10-CM code R57.0 and categorized into clinically relevant phenotypes, including acute myocardial infarction (AMI), heart failure (HF), arrhythmia-related shock, myocarditis/Takotsubo, valvular disease, and other etiologies. Survey-weighted analyses accounting for the complex sampling design were used for primary analyses. The primary outcome was in-hospital mortality. Secondary outcomes included use of mechanical circulatory support (MCS) and mechanical ventilation. Propensity score-matched analyses were performed as sensitivity analyses. Results Among 254,691 weighted CS hospitalizations, 158,747 (62.3%) occurred in men and 95,896 (37.7%) in women. In survey-weighted analyses, women had higher in-hospital mortality in AMI-related CS (36.1% versus 31.3%; OR, 1.24; 95% CI, 1.19-1.28), HF-related CS (30.5% versus 25.8%; OR, 1.27; 95% CI, 1.23-1.30), and arrhythmia-related CS (37.3% versus 31.6%; OR, 1.28; 95% CI, 1.20-1.38). Women were less likely to receive ECMO (2.4% versus 2.9%), IABP/Impella (13.1% versus 18.9%), or any MCS (14.6% versus 20.4%), but were more likely to receive mechanical ventilation (44.9% versus 42.9%). In propensity-matched analyses, mortality differences were attenuated but persisted in AMI-related, HF-related, and valvular CS. Conclusions Sex differences in CS outcomes and treatment utilization are strongly phenotype dependent. Women experienced higher mortality in major CS phenotypes while receiving less advanced mechanical circulatory support. These findings support early recognition, rapid phenotype classification, and sex-conscious but non-delayed escalation strategies for women with CS.