Validation of the SCAI Cardiogenic Shock Classification in 1,039 Patients Presenting with Cardiogenic Shock

Objectives: The Society of Cardiovascular Angiography and Interventions (SCAI) has recently proposed a new classification of cardiogenic shock (CS) dividing patients into different subgroups. However, this classification is still in need of validation. The aim of this study was to test the SCAI classification in a large clinical cohort of patients presenting with CS and to evaluate its ability to predict 30-day survival.

Methods: We interpreted the recent SCAI CS subgroups as (A) patients at risk of developing CS with large myocardial infarction (MI, creatine kinase > 1,000 U/L); (B) patients with signs and symptoms of CS but normal lactate (<2.0 mmol/L); (C) patients with classic CS with hypoperfusion and elevated lactate >2.0 mmol/L requiring treatment; (D) patients with deteriorating CS indicated by an elevated lactate >2 mmol/L which increases within the first hours despite treatment; (E) patients in extremis with ongoing cardiopulmonary resuscitation.

We applied this SCAI classification to 1,039 consecutive patients presenting with CS or large MI to a tertiary care hospital between October 2009 and October 2017. The association between SCAI classification and 30-day all-cause mortality was assessed by Cox regression analysis.

Results: Mean age was 66.7 (± 16.7) years; 70% were male. Mean lactate at baseline was 6.1 (± 5.2) mmol/L and 57.3% of the patients had cardiac arrest. Overall survival probability was 41.5% (95% confidence interval [CI]: 38.3–45.1%).

In view of the SCAI classification, the survival probability was 97.4% (95% CI: 92.4–100.0%) in class A, 55.7% (95% CI: 46.6–66.7%) in class B, 43.7% (95% CI: 38.9–49.1%) in class C, 30.4% (95% CI: 23.7–39.1%) in class D, and 22.6% (95% CI: 17.1–30.0%) in class E. Higher SCAI classification was significantly associated with a decrease in 30-day survival (p < 0.01).

Conclusion: In this large clinical register, SCAI classification was independently associated with 30-day survival. This study provides the first clinical validation of the recently proposed SCAI classification of CS and supports its use in clinical practice and research.

No conflict of interest has been declared by the author(s).