Phenotypes of cardiogenic shock after out-of-hospital cardiac arrest: the SCAI-V classification

BACKGROUND: Classifying cardiogenic shock (CS) after out-of-hospital cardiac arrest (OHCA) is challenging, with end-organ hypoperfusion arising from mechanisms distinct to non-arrested CS. AIMS: We sought to evaluate the performance of current CS classifications and to develop the Society for Cardiovascular Angiography and Interventions (SCAI)-V classification of CS after resuscitated OHCA. METHODS: We performed a retrospective analysis of an international derivation cohort (London, United Kingdom; GdaÅsk, Poland; n=627) and external validation of the 2x2 SCAI-V construct in the TTM-2 trial cohort (n=1,781). The primary outcome was mortality; the secondary outcome was non-neurological mortality at hospital discharge (derivation cohort) or at 180 days (TTM-2 cohort). RESULTS: In the derivation cohort, the median age was 63 years (interquartile range 53-74), and 76% were male. Applying the 2022 SCAI classification (SCAI-2022), 60% of patients had discordant haemodynamic parameters and lactate levels. We developed the SCAI-V classification, grouping patients according to their SCAI grade (shock absent or present) and lactate level (