Describing and Classifying Shock: Recent Insights

Cardiogenic shock continues to present a daunting challenge to clinicians, despite an increasing array of percutaneous mechanical circulatory support devices. Mortality for cardiogenic shock has not changed meaningfully in more than 20 years. There have been many attempts to generate risk scores or frameworks to evaluate cardiogenic shock and optimize the use of resources and assist with prognostication. These include the Intra-Aortic Balloon Pump in Cardiogenic Shock (IABP-SHOCK) II risk score, the CardShock score and the new CLIP biomarker score. This article reviews the Society for Cardiac Angiography and Interventions (SCAI) classification of cardiogenic shock and subsequent validation studies. The SCAI classification is simple for clinicians to use as it is based on readily available information and can be adapted depending on the data set that can be accessed. The authors consider the future of the field. Underlying all these efforts is the hope that a better understanding and classification of shock will lead to meaningful improvements in mortality rates.