Background: Cardiogenic shock (CS) is one of the major complications of myocardial infarction (MI) contributing to its high mortality and occurring in up to 10% of MI patients. Despite significant advancements in MI-related shock management, particularly with primary percutaneous coronary intervention, mortality in these patients remains high. Recently, the DANGER-SHOCK trial could demonstrate a survival benefit for selected CS patients using a microaxial flow pump to support the cardiac function. However, the applicability of these findings to a broader patient population remains uncertain. Thus, we aimed to characterize MI patients with CS and to describe the clinical change in CS status after MI treatment.

Methods: We used data from the prospective cohort study Biomarkers in Acute Cardiac Care, enrolling patients presenting to the emergency department with suspected MI. Patients with confirmed MI were retrospectively categorized according to the Society for Cardiovascular Angiography & Interventions (SCAI) classification based on all available clinical and laboratory information by two physicians, independently. In cases of discrepancy, classification was performed by a third physician. Patients initially classified as SCAI C-E were further categorized based to stabilization upon percutaneous coronary intervention as transient (reduction to SCAI A-B) or true shock (persisting SCAI C-E). We performed logistic regression analyses to describe the association clinical variables with SCAI categories. Furthermore, all patients were followed to assess all-cause mortality after 30 days.

Results: In total, 443 patients were included with 88% of patients initially classified as SCAI A, 2% as SCAI B, and 10% as SCAI C-E. In multivariable logistic regression analyses only symptom onset of less than 3h (OR 3.4; 95%CI 1.8-6.6) showed an independent association with severe CS (SCAI C-E), highlighting the acute nature of CS. Among these, only 24% of patients had a persistent CS, while most patients recovered to SCAI A or B (Figure 1). During 30 days follow-up, 12 patients died (mortality rate 2.7%), but higher SCAI categories did not predict mortality (Hazard ratio 1.84 (95%CI 0.35, 6.38)).

Interpretation: In a real-word setting, only 10% of all MI patients presented with CS and most patients showed a recovery of CS after MI treatment. This data does not support widespread use of mechanical circulatory support for patients with MI-related CS as guideline-directed revascularizatoin was a sufficient treatment for the majority in the acute setting.

Figure 1: Alluvial diagram showing the change in SCAI categories before and after MI treatment.