Impact of Baseline Cardiogenic Shock Severity on Outcomes in Patients Treated With Impella Device

Risk stratification of patients with cardiogenic shock (CS) is of considerable importance. We aimed to test the utility of the Society for Cardiovascular Angiography and Intervention shock staging system recently refined by the CS Working Group in an Asian population and to investigate its association with in-hospital adverse events.

From the Japanese nationwide registry of Impella, the patients with CS who successfully received Impella support between February 2020 and December 2023 were included and assigned to any stage according to the CS Working Group-refined Society for Cardiovascular Angiography and Intervention staging system. We set the primary end point as in-hospital death and explored it within each stage, with stage B as a reference.

In total, 4643 patients were analyzed (median age, 69 years; women, 23.3%; CS due to acute myocardial infarction, 61.7%), and 122, 588, 1905, and 2058 patients were in stages B, C, D, and E, respectively. After adjustment with potential confounders, stage C had no significant difference in in-hospital death (odds ratio, 1.12 [95% CI, 0.69-1.80]; P=0.653). However, with adjusted analysis, stages D and E had a significantly higher rate of in-hospital death (stage D: odds ratio, 2.41 [95% CI, 1.55-3.77]; P<0.001; stage E: odds ratio, 4.90 [95% CI, 3.14-7.66]; P<0.001).

The CS Working Group-refined Society for Cardiovascular Angiography and Intervention staging system at baseline has a satisfactory association with in-hospital death in the more progressive stage; however, the system seems to have a lower power in the earlier phase of CS. Further investigation is warranted to establish a more accurate staging system.