SCAI updates consensus framework for assessing cardiogenic shock severity

The Society for Cardiovascular Angiography & Interventions (SCAI) today released the 2026 SCAI SHOCK Classification Expert Consensus Update, providing refined guidance to help clinicians from diverse settings prioritize and recognize inadequate organ perfusion across a broad range of shock presentations, assess shock severity over time, and determine whether treatment is restoring adequate circulation.

Published in JSCAI in conjunction with AHA Scientific Sessions 2026, the updated classification strengthens a common framework for a life-threatening condition that can evolve rapidly, incorporating new data and providing field-wide consensus.

Cardiogenic shock occurs when impaired cardiac function prevents adequate blood flow to the body's organs and remains a life-threatening condition with substantial mortality. Since its introduction in 2019, the SCAI SHOCK Classification has been adopted across clinical care, research, and regulatory settings, creating a common language for assessing and communicating cardiogenic shock severity. Clinicians and researchers use it routinely now to assess risk, guide evaluation, and track changes in a patient's condition over time.

One area discussed in detail is the differentiation of hypotension and hypoperfusion. A patient's blood pressure may look acceptable even when vital organs are not receiving adequate blood flow. One of the most important messages of this update is that clinicians must look beyond blood pressure alone when assessing shock severity, as perfusion to organs is the clinical arbiter that tracks with survival. By emphasizing hypoperfusion over hypotension, along with serial reassessment and patient trajectory, the updated framework helps care teams recognize risk earlier, communicate more effectively, and make better-informed treatment decisions as a patient's condition evolves."

Srihari S. Naidu, MD, MSCAI, SCAI past president and co-chair of the consensus writing group

The 2026 update addresses practical questions that have emerged as clinicians and researchers have applied the classification across a broader range of patient populations and care settings. The update places greater emphasis on identifying the underlying shock phenotype, recognizing hypoperfusion, tracking a patient's trajectory over time, and assessing whether treatment is restoring adequate circulation. The updated document addresses these questions while preserving the simplicity and practicality that have supported widespread global adoption.

"A classification system should reflect the patient's condition, not simply the treatments being used," said David A. Baran, MD, FSCAI, co-chair of the consensus writing group. "The updated framework places greater emphasis on perfusion, serial reassessment, and clinical trajectory, helping clinicians understand whether a patient's condition is improving, worsening, or remaining unchanged over time."

Serial reassessment is therefore essential. The document emphasizes changes in physical findings, biochemical markers, imaging, and hemodynamics to assess deterioration or recovery. A stage assigned at presentation should be reassessed at regularly defined intervals as the patient's condition changes, and the update emphasizes that trajectory over time typically provides greater prognostic value than a single assessment.

Additional refinements clarify key aspects of the staging framework, including identifying with more granularity those at risk for shock progression, recognizing worsening shock (or failure to improve) despite treatment, and applying the Arrest modifier in patients with cardiac arrest and uncertain neurologic recovery.

The document expands guidance for acute myocardial infarction-related, heart failure-related, valvular, right ventricular-predominant, mixed, post-cardiotomy, and pediatric cardiogenic shock. These sections address how underlying disease, clinical phenotype, and patient characteristics affect presentation, assessment, and interpretation of severity.

"Every handoff is an opportunity to communicate how severe the shock is and how the patient is responding to therapies," said Alexander G. Truesdell, MD, FSCAI, a member of the consensus writing group and senior author. "Whether a patient is being transferred between clinicians, units, or institutions, a shared staging framework provides critical context. Documenting both stage and trajectory gives the receiving team a clearer picture of the patient's course, supports continuity of care, and helps align treatment decisions across specialties. Looking at shock through different clinician vantage points, in particular, is highlighted in the updated guidance."

Two resources accompany the document: an updated bedside checklist to support structured assessment and a quality improvement tool. To access these, visit the online SCAI SHOCK Resources Center.

Implementation guidance, including a "core data set" of clinical information, encourages teams to incorporate staging and serial reassessment into routine documentation, handoffs, and multidisciplinary discussions, from emergency medical services and the emergency department through the catheterization laboratory, operating room, and intensive care unit. The update also addresses research applications, including clinical trial eligibility, treatment response evaluation, and comparisons across study populations. It encourages prospective stage assignment using prespecified criteria to support more consistent interpretation across clinicians and research sites.

"Effective shock care depends on collaboration across specialties and care settings," said J. Dawn Abbott, MD, MSCAI, president of SCAI. "The SCAI SHOCK Classification has become one of the most widely recognized frameworks for assessing cardiogenic shock and communicating severity across disciplines. This update reflects extensive clinical experience, validation studies, and multidisciplinary collaboration. By refining how clinicians assess perfusion, trajectory, and response to treatment, it provides a stronger foundation for patient care, quality improvement initiatives, and future research in one of cardiovascular medicine's most challenging conditions."

The 2026 SCAI SHOCK Classification Expert Consensus Update is endorsed by the American College of Cardiology (ACC), Advanced Cardiac Therapies Improving Outcomes Network (ACTION), American Heart Association (AHA), Canadian Cardiovascular Critical Care Society (CANCARE), European Association for Cardio-Thoracic Surgery (EACTS), Heart Failure Society of America (HFSA), International Society for Heart & Lung Transplantation (ISHLT), Society of Critical Care Medicine (SCCM), Society of Critical Care Cardiology (SOCCC), and the Society of Thoracic Surgeons (STS).