Dementia, Treatment Intensity, and Outcomes in Acute Myocardial Infarction with Cardiogenic Shock

BACKGROUND: Dementia is associated with lower use of invasive therapies and poorer outcomes after acute myocardial infarction (AMI). However, its impact in AMI complicated by cardiogenic shock (AMICS), where timely invasive management is critical for survival, remains poorly characterized. We evaluated the association between dementia, treatment intensity, and in-hospital outcomes in AMICS. METHODS: We performed a retrospective cohort study using the National Inpatient Sample (2016-2019). Adults hospitalized with AMICS were identified using ICD-10-CM codes and stratified according to pre-existing dementia. Outcomes were in-hospital mortality, major adverse cardiovascular and cerebrovascular events (MACCE), and use of invasive and supportive therapies. Multivariable logistic regression adjusted for demographic, hospital, socioeconomic, presentation, and comorbidity characteristics estimated adjusted odds ratios (aORs) with 95% confidence intervals (CIs). We additionally performed 1:1 propensity score matching. RESULTS: Among 226,570 patients with AMICS, 10,895 (4.8%) had dementia. Patients with dementia were older, more frequently female, had greater comorbidity burden, and fewer markers of acute disease severity. They underwent coronary angiography (50.2% vs. 70.4%), percutaneous coronary intervention (PCI) (39.3% vs. 55.0%), coronary artery bypass grafting (CABG) (5.2% vs. 17.5%), mechanical ventilation (34.1% vs. 45.5%), and circulatory support (23.7% vs. 46.4%) less frequently than those without dementia (all p < 0.001). Dementia was independently associated with lower odds of coronary angiography (aOR 0.50, 95% CI 0.48-0.52), PCI (aOR 0.58, 95% CI 0.55-0.61), CABG (aOR 0.31, 95% CI 0.28-0.34), and circulatory support (aOR 0.49, 95% CI 0.46-0.51), as well as higher odds of in-hospital mortality (aOR 1.17, 95% CI 1.12-1.22) and MACCE (aOR 1.13, 95% CI 1.09-1.18). Results were consistent in the propensity-matched pairs. CONCLUSIONS: Among patients hospitalized with AMICS, dementia was independently associated with lower treatment intensity and worse in-hospital outcomes despite fewer markers of acute clinical severity. These findings highlight the importance of individualized, goal-concordant decision-making while avoiding unwarranted limitation of potentially life-saving therapies.