The Society for Cardiovascular Angiography and Intervention (SCAI) has classified cardiogenic shock into stages from A through E. This was developed by a multidisciplinary team from cardiology (interventional, advanced heart failure and noninvasive), emergency medicine, critical care and cardiac nursing.
Stage A: “At risk” for cardiogenic shock – large myocardial infarction or heart failure, but not yet in shock, with normal mentation and systolic blood pressure of 100 mm Hg or more.
Stage B: “Beginning” shock – hypotension or tachycardia without features of hypoperfusion (normal mentation). Systolic BP < 90, mean arterial pressure (MAP) <60 or 30 mm Hg fall in BP.
Stage C: “Classic” cardiogenic shock – has hypotension with features of hypoperfusion, needing inotropes and mechanical circulatory support.
Stage D: “Deteriorating” – needs multiple inotropes or mechanical circulatory support to maintain perfusion. Initial interventions have failed.
Stage E: “Extremis” – in cardiac arrest with ongoing CPR or ECMO support, nearly pulseless, hypotension despite maximal support.
This is a brief description of the stages. More detailed description is available in the SCAI statement (Free Full Text).
A study from Mayo Clinic retrospectively classified patients who were admitted in cardiac intensive care unit between 2007 and 2015 . Of the total 10,004 patients, 43.1% had acute coronary syndrome, 46.1% had heart failure, and 12.1% had cardiac arrest. 46% of the patients were in stage A and 1% in stage E with others in between. Unadjusted hospital mortality was 3% in stage A and 67% in stage E, with others in between. When assessed at the time of admission to cardiac intensive care unit, the SCAI shock stage provided robust hospital mortality risk stratification.