Beyond the Syndromic Approach in Critical Care: Identifying Biomarker-driven Subphenotypes of Circulatory Shock

Traditionally, circulatory shock subgroups are defined according to hemodynamic profile (e.g., hypovolemic, distributive, cardiogenic) and etiology (e.g., trauma, infection, myocardial infarction among others) and are incorrectly considered as homogeneous clinical syndromes. Emerging translational evidence highlights the existing molecular heterogeneity in the circulatory shock syndrome. Such findings raise a major issue in assessing neutral clinical trial results in circulatory shock as a given intervention effect (e.g., fluid management, vasopressors/inotropes, mechanical circulatory support) may preferentially impact different subgroups (i.e., heterogeneity of treatment effect).

Accordingly, identifying distinct biological subphenotypes with different mechanistic signatures may provide new insights regarding the pathophysiology of circulatory shock. This may allow predictive enrichment (i.e., identifying those patients most likely to benefit from a particular therapy) and biomarker-driven or phenotype-driven patient selection in future clinical trials to assess a personalized therapy (i.e., prospective enrollment based on a biological signature).

The ShockCO-OP Research Program aims to use unsupervised model-based clustering (i.e., regardless of outcome) to reanalyze existing clinical and biological data in several European and North American prospective cohorts and clinical trials to identify distinct biomarker-driven subphenotypes in circulatory shock syndromes, their underlying molecular signatures (proteomics, transcriptomics), their association with outcome and their response to different interventions.