Predicting the development of in-hospital cardiogenic shock in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention: the ORBI risk score

Aims To derive and validate a readily useable risk score to identify patients at high-risk of in-hospital ST-segment elevation myocardial infarction (STEMI)-related cardiogenic shock (CS). Methods and results In all, 6838 patients without CS on admission and treated by primary percutaneous coronary intervention (pPCI), included in the Observatoire Regional Breton sur l'Infarctus (ORBI), served as a derivation cohort, and 2208 patients included in the obseRvatoire des Infarctus de Cote-d'Or (RICO) constituted the external validation cohort. Stepwise multivariable logistic regression was used to build the score. Eleven variables were independently associated with the development of in-hospital CS: age >70 years, prior stroke/transient ischaemic attack, cardiac arrest upon admission, anterior STEMI, first medical contact-to-pPCI delay >90 min, Killip class, heart rate >90/min, a combination of systolic blood pressure <125 mmHg and pulse pressure <45 mmHg, glycaemia >10 mmol/L, culprit lesion of the left main coronary artery, and post-pPCI thrombolysis in myocardial infarction flow grade <3. The score derived from these variables allowed the classification of patients into four risk categories: low (0-7), low-to-intermediate (8-10), intermediate-to-high (11-12), and high (>= 13). Observed in-hospital CS rates were 1.3%, 6.6%, 11.7%, and 31.8%, across the four risk categories, respectively. Validation in the RICO cohort demonstrated in-hospital CS rates of 3.1% (score 0-7), 10.6% (score 8-10), 18.1% (score 11-12), and 34.1% (score >= 13). The score demonstrated high discrimination (c-statistic of 0.84 in the derivation cohort, 0.80 in the validation cohort) and adequate calibration in both cohorts. Conclusion The ORBI risk score provides a readily useable and efficient tool to identify patients at high-risk of developing CS during hospitalization following STEMI,which may aid in further risk-stratification and thus potentially facilitate pre-emptive clinical decision making.