UTILITY OF SHOCK INDEX FOR PREDICTION OF CARDIOGENIC SHOCK DEVELOPED DURING PRIMARY PERCUTANEOUS CORONARY INTERVENTION
Introduction: Cardiogenic shock (CS) is a distinct clinical entity with a high morbidity and mortality. CS after primary PCI usually portends a bad prognosis and needs prompt recognition. Shock Index (SI) serves as one of the valuable non-invasive marker for development of CS. Methods: This was a single centre prospective observational study wherein patients with ST elevated myocardial infarction (STEMI) were enrolled. In all these patients, prior to performing the coronary angiogram, shock index (SI) was calculated as heart rate (HR) divided by SBP on admission. Primary outcome was the occurrence of CS during the period of hospitalisation post primary PCI. Study population was divided into two groups: Group 1: patients with ACS without CS and Group 2: patients with ACS with CS. Results: A total of 240 patients were included in the study of whom 19 (7.9%) developed CS. Patients with CS (Group 2) had a significantly higher frequency of anterior wall MI, prior history of stroke, heart rate and a lower left ventricular ejection fraction. Multivariate logistic regression analysis revealed pre-procedure SBP, pre-procedure HR, Killip class, serum creatinine and Shock Index to be the independent predictors of developing CS post primary PCI. ROC curve showed that SI (AUC: 0.8113 ; P=0.004) had a better predictive ability as compared to pre-procedural heart rate (AUC: 0.7111; P=0.01) and pre-procedural SBP (AUC: 0.7582; P=0.001) for prediction of CS post primary PCI. Conclusion: SI is a promising tool to detect presence of shock post primary PCI in STEMI patients.