Echocardiographic findings in cardiogenic shock due to acute myocardial infarction versus heart failure

Background: Acute myocardial infarction (AMI) is the prototypical cause of cardiogenic shock (CS), yet CS due to heart failure (HF-CS) is increasingly common. Little is known regarding cardiac function in AMI-CS versus HF-CS. We compared transthoracic echocardiography (TTE) findings in AMI-CS versus HF-CS and identified predictors of mortality in AMI-CS patients.

Methods: We performed a single-center, retrospective analysis of CS admissions between 2007 and 2018. We compared baseline demographic and TTE parameters in patients with AMI-CS and HF-CS as well as ST elevation myocardial infarction (STEMI)-CS versus non-ST elevation myocardial infarction (NSTEMI)-CS.

Results: We included 893 unique patients, including 581 (65%) with AMI-CS. AMI-CS patients were older but had lower illness severity and non-cardiac comorbidity burden. AMI-CS patients had better left ventricular function (LVEF 35% versus 28%), lower biventricular filling pressures, and higher stroke volume versus those with HF-CS. Among TTE measurements, myocardial contraction fraction had the highest discrimination for mortality in AMI-CS (AUC: 0.64); AUC values for LVEF and SOFA score were 0.61 and 0.65, respectively. Differences in TTE findings between STEMI-CS versus NSTEMI-CS were modest. There were no significant differences in unadjusted or adjusted in-hospital mortality between AMI-CS and HF-CS (31% versus 35%) or STEMI-CS and NSTEMI-CS (31% versus 30%) groups (all p > 0.05).

Conclusions: Patients with HF-CS and AMI-CS differ in terms of clinical and TTE variables yet have similar prognoses. TTE is useful in determining prognosis of patients admitted with AMI-CS and may allow for early triage and directed therapy.