Abstract Body: Background: Cardiogenic Shock (CGS) is the most common cause of death in hospitalized patients with Acute Myocardial Infarction (AMI). This study identified the characteristics of those selected and not selected to receive Mechanical Circulatory Support (MCS). We hypothesized that mortality in non-selected patients would correlate with the reason for non-support.
Methods: CGS patients were identified as follows: blood pressure <80 mmHg or <90 mmHg on vasopressors; ICD-10 diagnosis of cardiogenic shock (R57.0); acute MI or other ischemic heart disease or heart failure; left ventricular ejection fraction <40%; severe aortic stenosis patients were excluded.
Results: During one year (2022) in our medical center, 211 CGS patients were treated: 95 (45%) received MCS with p-VAD, Intra-aortic Balloon Pump, or Extra Corporeal Membrane Oxygenation; 116 (55%) patients did not receive MCS. Comparing MCS to non-MCS patients, the mean age was 64 versus 70 years; underlying diagnoses were ST elevation MI in 44 (46%) versus 8 patients (7%), non-STEMI in 23 (24%) versus 35 patients (30%), other ischemic heart disease in 6 (6%) versus 19 patients (16%), heart failure in 88 (93%) versus 115 patients (99%). Shock type was defined as isolated cardiogenic shock in 74 (78%) versus 54 patients (46%), and cardiogenic with septic shock in 18 (19%) versus 60 patients (52%). Overall hospital mortality for CGS patients receiving MCS was 33 of 95 (35%). In contrast, hospital mortality for non-MCS patients was 59 of 116 patients (51%, P<.01 compared to MCS patients). Reasons for electing not to place MCS were advanced co-morbidities judged to preclude survival (53 patients, mortality 60%), mixed shock (38 patients, mortality 63%) and rapid resolution of shock with pharmacological treatment (25 patients, mortality 12%). In the advanced co-morbidity group, cardiac arrest was associated with a particularly high mortality (23 of 32 arrest patients, 72% mortality).

Conclusion: In a medical center that treats a high volume of CGS patients with MCS, non-selection of MCS for CGS remains relatively common (55%). Mortality in these non-MCS CGS patients is high when advanced co-morbidities or mixed etiology shock are present. Patients who have rapid resolution of shock have a substantially better course. Clinician knowledge of these different categories and outcomes for non-selection of MCS may allow clinicians to improve selection and non-selection of CGS patients for MCS and may improve outcomes.