Prognostic validation and risk stratification of the Society for Cardiovascular Angiography and Interventions cardiogenic shock classification in a large, real-world intensive care unit cohort in South Korea

BACKGROUND: Cardiogenic shock (CS) imparts a high mortality rate, yet a standardized classification of its severity remains lacking. The Society for Cardiovascular Angiography and Interventions (SCAI) proposed a five-stage classification scheme to improve risk stratification, but its prognostic value in real-world intensive care unit (ICU) populations is still insufficiently validated. METHODS: We retrospectively analyzed 3,074 adults admitted to the medical and cardiovascular ICUs under the Division of Cardiology at a tertiary academic medical center between 2010 and 2019. SCAI shock stages (A-E) were assigned at admission using data on hemodynamic instability, hypoperfusion, clinical deterioration, and refractory shock. The primary outcome was ICU mortality. RESULTS: ICU mortality rates across stages A-E were 0.5%, 4.3%, 5.2%, 18.8%, and 53.2% (P