Right to Left Cardiac Power Output- New Prognosticator in STEMI Patients With Cardiogenic Shock (R-Shock)

Abstract

ST elevation myocardial infarction (STEMI) is a leading cause of cardiogenic shock (CS) and carries substantial mortality. Cardiac power output (CPO) is the strongest predictor of clinical outcome in CS, and worse outcomes result from concomitant right and left ventricular failure. Right ventricular performance is calculated using right sided CPO. Our aim was to measure the right sided CPO and compute their ratio to predict in-hospital mortality in STEMI patients with cardiogenic shock. This was a retrospective observational study of consecutive STEMI patients with CS that developed within the first 24hours of admission requiring left and right cardiac catheterization at a large tertiary care center from January 2014-December 2018. One hundred sixty-four patients identified with STEMI; 46% (75) excluded due to incomplete data. 88 remaining patients, 52.8% (47) developed CS. 98.9% within 24 hours. Mean left & right CPO 0.62 (SD 0.3) and 0.22 (SD 0.13), PAPi score 1.81. Logistic regression analysis indicated odds ratio of in-hospital mortality lower for low left CPO, high right CPO and low ratio of left to right CPO (95% CI; 0.69, 0.34, 1.20; 1.38, 0.87, 2.20; 0.52, 0.28, 1.00 respectively). This is the first study to assess right sided CPO and ratio of right and left side CPO and mortality. Our study indicates that there is trend towards higher in-hospital mortality in patients with high right sided CPO and lower ratio of left to right CPO. The exploratory results of this study need to be confirmed in a larger population.