Assessing mortality risk in cardiogenic shock: the role of bedside echocardiography in acute myocardial infarction

Acute myocardial infarction (AMI) accounts for 81% of cardiogenic shock (CS) cases. The incidence of CS in AMI patients ranges from 3% to 13%, with a mortality rate of approximately 40% within the first 30 days and up to 50% within the first year. The pathophysiology of CS in the context of AMI involves myocardial ischemia leading to regional necrosis and a decrease in cardiac contractile mass, resulting in reduced ventricular function. Consequently, bedside echocardiography plays an essential role in assessing such patients.

This study aimed to evaluate bedside echocardiographic predictors for in-hospital mortality in patients experiencing CS following AMI.

This prospective cross-sectional study was conducted from March 20 to October 20, 2024. Patients admitted with acute coronary syndrome were closely monitored, and those who developed CS were included in the study. Bedside echocardiography was performed for each patient in this study. Patients were categorized into two groups based on outcomes: those who died (mortality group) and those who survived (survival group).

Of the 1,166 patients admitted for acute coronary syndrome at the Clinic of Cardiology during the seven-month study period, 86 (7.4%) developed CS. Among these, 44 patients (51%) died, while the overall mortality rate following acute coronary syndrome was 3.8%. Table 1 compares bedside echocardiographic parameters between the two groups. Significant differences between groups were observed in left atrial diameter, right ventricular dimensions, and interventricular septum thickness, all of which were larger in the mortality group. Table 1 presents the differences between echocardiographic parameters. Although all patients with CS had a reduced ejection fraction, there were no significant differences between the groups in this measure. The echocardiographic parameters that were statistically significant were included in a multiple regression model, which demonstrated an explanatory power of approximately 20% (R² = 0.198) and statistical significance (p = 0.03) (Table 2a). An increased left atrial diameter emerged as the only independent predictor of fatal outcomes in CS (Table 2b).