Cardiogenic shock: a major challenge for the clinical trialist

PURPOSE OF REVIEW: Cardiogenic shock (CS) results in persistently high short-term mortality and a lack of evidence-based therapies. Several trials of novel interventions have failed to show an improvement in clinical outcomes despite promising preclinical and physiologic principles. In this review, we highlight the challenges of CS trials and provide suggestions for the optimization and harmonization of their design. RECENT FINDINGS: CS clinical trials have been plagued by slow or incomplete enrolment, heterogeneous or nonrepresentative patient cohorts, and neutral results. To achieve meaningful, practice-changing results in CS clinical trials, an accurate CS definition, a pragmatic staging of its severity for appropriate patient selection, an improvement in informed consent process, and the use of patient-centered outcomes are required. Future optimizations include the use of predictive enrichment using host response biomarkers to unravel the biological heterogeneity of the CS syndrome and identify subphenotypes most likely to benefit from individualized treatment to allow a personalized medicine approach. SUMMARY: Accurate characterization of CS severity and its pathophysiology are crucial to unravel heterogeneity and identify the patients most likely to benefit from a tested treatment. Implementation of biomarker-stratified adaptive clinical trial designs (i.e., biomarker or subphenotype-based therapy) might provide important insights into treatment effects.