Cardiogenic Shock Prior to Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction: Outcomes and Predictors of Mortality (ANZACS-QI 73)

Abstract

Cardiogenic shock (CS) is a serious complication of acute myocardial infarction (MI) and is associated with significant mortality. We describe a contemporary, real-world cohort of patients with ST-elevation MI (STEMI) and CS, including 30-day mortality and clinically relevant predictors of mortality. All patients presenting with STEMI who were treated with percutaneous coronary intervention (PCI) in New Zealand (2016 to 2020) were identified from the Aotearoa New Zealand All Cardiology Services Quality Improvement (ANZACS-QI) registry and stratified based on their Killip class on arrival to the cardiac catheterisation laboratory. Primary outcome was 30-day all-cause mortality. Multivariable analysis was used to identify predictors of mortality prior to PCI and to develop a mortality scoring system. In total, 6,649 patients were identified, including 192 (2.9%) Killip IV (CS) patients. Thirty-day mortality was 47.5% in patients with CS, 14.6% in those with heart failure without shock, and 3% in those without heart failure. Independent predictors of 30-day mortality for patients with CS were: estimated glomerular filtration rate <60 mL/min/1.73m2 (relative risk [RR] 1.89, 95% confidence interval [CI] 1.39-2.58), cardiac arrest (RR 1.54, 95% CI 1.15-2.06), diabetes (RR 1.31, 95% CI 1.01-1.70), female sex (RR 1.32, 95% CI 1.01-1.72), femoral arterial access (RR 1.42, 95% CI 1.06-1.90) and left main stem culprit (RR 2.16, 95% CI 1.65-2.84). A multivariable Shock score was developed which predicts 30-day mortality with good global discrimination (area under the curve 0.79, 95% CI 0.73-0.85). In this national cohort, the 30-day mortality for STEMI patients presenting with CS treated with PCI remains high, at nearly 50%. The ANZACS-QI Shock score is a promising tool for mortality risk stratification prior to PCI but requires further validation.