Criteria for Defining Stages of Cardiogenic Shock Severity

Background: Risk-stratifying patients with cardiogenic shock (CS) is a major unmet need. The recently proposed Society for Cardiovascular Angiography and Interventions (SCAI) staging system for CS severity lacks uniform criteria defining each stage. Objectives: The purpose of this study was to test parameters that define SCAI stages and explore their utility as predictors of in-hospital mortality in CS. Methods: The CS Working Group registry includes patients from 17 hospitals enrolled between 2016 and 2021 and was used to define clinical profiles for CS. We selected parameters of hypotension and hypoperfusion and treatment intensity, confirmed their association with mortality, then defined formal criteria for each stage and tested the association between both baseline and maximum Stage and mortality. Results: Of 3,455 patients, CS was caused by heart failure (52%) or myocardial infarction (32%). Mortality was 35% for the total cohort and higher among patients with myocardial infarction, out-of-hospital cardiac arrest, and treatment with increasing numbers of drugs and devices. Systolic blood pressure, lactate level, alanine transaminase level, and systemic pH were significantly associated with mortality and used to define each stage. Using these criteria, baseline and maximum stages were significantly associated with mortality (n = 1,890). Lower baseline stage was associated with a higher incidence of stage escalation and a shorter duration of time to reach maximum stage. Conclusions: We report a novel approach to define SCAI stages and identify a significant association between baseline and maximum stage and mortality. This approach may improve clinical application of the staging system and provides new insight into the trajectory of hospitalized CS patients.