Definition, Classification, and Management of Primary Noncardiac Causes of Cardiogenic Shock.

Cardiogenic shock (CS) is a complex syndrome, presenting with a critical state of cardiac output insufficient to support end-organ perfusion requirements. Contemporary CS classification recognizes broad categories of primary cardiac etiologies of CS, such as acute myocardial infarction and heart failure. Primary noncardiac etiologies of CS, however, are poorly described in literature and have not been captured by any contemporary classification, leading to challenges in diagnosing and managing these cases. In this review, we propose that primary noncardiac causes of CS be recognized as its own category that builds on the original Shock Academic Research Consortium classification with its own additional modifiers. We present a detailed framework that groups each noncardiac cause by its underlying disease mechanism (vascular, infectious, inflammatory, traumatic, toxic, cancer related, endocrine, metabolic) and review available literature on their respective management strategies. We expect that the ability to classify primary noncardiac causes of CS will help with early identification and targeted management of the primary noncardiac insult, support patients through their shock state, and may lead to improvement of in-hospital CS mortality rates in clinical practice. Moreover, this new framework can further assist clinical trial classifications to properly phenotype CS for clinical research purposes.