Early risk stratification of patients with acute myocardial infarction complicated by severe cardiogenic shock - The ECLS-SHOCK Risk Score

Abstract Background Prognosis after acute myocardial infarction complicated by cardiogenic shock (AMI-CS) remains dismal. Timely risk stratification is crucial to make adequate treatment decisions. Existing CS scores are limited to either registry data, included not readily available parameters (such as coronary flow after revascularisation, cystatin C or interleukin-6), or are not tailored to patients with AMI-CS. Purpose The aim of this study was to develop a readily available and easy-to-use risk prediction tool for 30-day mortality in patients with severe AMI-CS derived from the ECLS-SHOCK (Extracorporeal Life Support in Infarct-Related Cardiogenic Shock) trial. Methods Backward stepwise regression analysis was used to develop the risk score across 43 centres in two countries. Results Five variables emerged as independent predictors for 30-day mortality and were used as risk score parameters: age ≥69 years, female sex, ≥3 known cardiovascular risk factors (i.e., hypertension, dyslipidaemia, diabetes, smoking or known vascular disease), baseline arterial lactate ≥7.1 mmol/L and performed resuscitation. Between 1 and 7 points were attributed to each variable, resulting in a score with three risk categories: low (0 to 1), intermediate (2 to 3) and high (4 to 7) (Figure). The observed 30-day mortality rates were 23%, 50% and 80% in each risk category (p<0.001) with a good discrimination at an area under the curve of 0.75. A stepwise increase in mortality between the different risk score categories was observed in Kaplan-Meier analyses (p<0.001 for low vs. intermediate, intermediate vs. high and low vs. high; see Figure). Conclusion The ECLS-SHOCK risk score can be easily and promptly calculated in daily clinical practice and correlated with mortality in patients with severe AMI-CS. It may help stratify patient risk for short-term mortality and facilitate early clinical decision making.