The same, but different. 2025-SCAI and CSWG-SCAI shock classifications in heart failure-related cardiogenic shock

Introduction The Society for Cardiovascular Angiography & Interventions (SCAI) cardiogenic shock (CS) classification has been complemented by newer staging systems, including the Cardiogenic Shock Working Group classification (CSWG-SCAI) and the updated SCAI-2025 (1,2). The CSWG-SCAI focusses on selected ranges of non-invasive clinical parameters reflective of hypotension and hypoperfusion, whereas the SCAI-2025 classification recommends incorporation of invasive hemodynamic parameters for severity staging as hemodynamic profiling positively impacts prognosis. However, invasive metrics are often unavailable at heart failure related-CS (HF-CS) diagnosis, potentially hampering its clinical use in the early phase of CS. During this phase, rapid bedside staging is essential to guide escalation or de-escalation of CS therapy in attempt to improve prognosis. Purpose This study aims to compare the prognostic performance of the CSWG-SCAI and SCAI-2025 classifications at HF-CS diagnosis and after 24 hours. Methods This is a retrospective, multicenter study of patients admitted with HF-CS. HF-CS was diagnosed at the time of initiation of vasoactive–inotropic therapy. The primary endpoint was time-to-event 30-day all-cause mortality. Cox models were used to analyze the relationship between SCAI definitions and survival, adjusting for age, sex, body mass index, and chronic kidney disease, from both baseline and 24 hours. Discrimination was evaluated as the bootstrapped out-of-sample average time-dependent AUC over 30-day window (iAUC). Results In 469 HF-CS patients (mean age 70 ±14 years, 37% female) without available invasive hemodynamic data, 21% had de novo heart failure and 47% had LVEF <30%. Both classifications were associated with 30-day mortality at the time of HF-CS diagnosis (P<0.0001 for CSWG-SCAI and P=0.016 for SCAI-2025) and at 24 hours (P=0.01 for both). Discriminative performance of the models was moderate and comparable between the two scoring systems at both diagnosis (iAUC SCAI 2025 0.63, iAUC CSWG 0.65, DiAUC 0.02 (-0.04, 0.08) p = 0.44) and at 24 hours after HF-CS diagnosis iAUC SCAI 2025 0.64, iAUC CSWG 0.63, DiAUC -0.01 (-0.08, 0.05) p = 0.77). Conclusions Among patients with HF-CS, the CSWG–SCAI and SCAI-2025 classifications showed similar prognostic discrimination at HF-CS diagnosis and after 24 hours. However, the CSWG–SCAI 2025 classification appears to better prognosticate HF-CS patients as it demonstrated a clear, stepwise increase in mortality from Stage A to B at 24 hours. Additionally, the SCAI-2025 classification failed to stage patients as Stage D since it requires documented failure of CS therapy. Taken together, these observations suggest that CSWG–SCAI may be especially useful during the initial stages of HF-CS management. Alternatively, in more advanced trajectories in which hemodynamic indices are available, the SCAI-2025 may prove a superior a CS staging systemFigure 1.