Outcomes for Mechanically Ventilated Patients with Acute Myocardial Infarction Admitted to Medical Vs Cardiac Intensive Care Units

Background: Acute myocardial infarction (AMI) remains a common reason for admission to the intensive care unit (ICU). However, there is limited data comparing outcomes for patients with AMI admitted to specific ICUs. Objectives: The purpose of this study was to assess clinical outcomes between patients with AMI requiring invasive mechanical ventilation admitted to the medical ICU (MICU) compared to cardiac (CICU). Methods: We utilized the Vizient Clinical Data Base to identify patients with a primary diagnosis of AMI between October 2015 and December 2019 and requiring invasive mechanical ventilation. Using multivariable logistic regression, we compared clinical outcomes for patients admitted to the MICU vs CICU. Results: We identified 12,639 patients, 25.2% (n = 3,185) of which were admitted to a MICU and 74.8% (n = 9,454) to a CICU. Patients admitted to a CICU were more likely to present with STEMI (57.0% vs 42.8%), cardiogenic shock (46.0% vs 37.4%), and require mechanical circulatory support and vasoactive medications (all, P < 0.001). Median ventilator days were 4 days in both ICUs and not statistically different after multivariable adjustment (P = 0.81). In-hospital mortality was 42.7% compared to 41.3% for MICU vs CICU admissions, respectively (P = 0.15). After multivariable adjustment, CICU admission was associated with lower in-hospital mortality (OR: 0.85, 95% CI: 0.78-0.93, P = 0.001), which persisted when stratified by cardiogenic shock, cardiac arrest, STEMI, largest hospital size (>750 beds), and teaching hospitals (all, P < 0.05). Conclusions: Admission to the CICU, as compared to MICU, was associated with lower in-hospital mortality for patients with AMI. These findings may support optimal triage of critically ill patients with AMI.