Abstract 12923: Lack of Concordance Between Parameters Defining Cardiogenic Shock in Patients With ST Elevation Myocardial Infarction

Abstract

Introduction: In stark contrast to a ~3-5% in-hospital mortality in all comer ST Elevation Myocardial Infarction (STEMI) patients, ~40-50% of STEMI patients complicated by cardiogenic shock (CS) die during their index-hospital admission. None of the pharmaco-mechanical circulatory support therapies have demonstrated survival benefit in CS, likely due to our inability to objectively define and identify CS in the “pre-shock” state. As per the current guidelines, CS is defined as either (1) systolic blood pressure (SBP) ≤ 90mmHg, (2) cardiac-index (CI) <1.8 L/min/m 2 or <2.2 L/min/m 2 with inotropic/vasopressor support in presence of pulmonary capillary wedge pressure ≥15 mmHg, and/or (3) lactate >2 mmol/L. These parameters are used interchangeably. however, data comparing these parameters is lacking. Objective: (1) To identify the incidence of CS using the above three parameters, and (2) assess the concordance between these parameters in STEMI patients . Methods: CI (total body impedance method), SBP and lactate were measured pre- and post-primary percutaneous coronary intervention (PPCI) in consecutive STEMI patients. Results: Sixty-eight STEMI patients (32% female) with a mean age of 65.8 years were recruited. Based upon lactate, CI and SBP the incidence of CS pre-PPCI was 47%, 26% and 17% (Panel-A). Poor concordance was seen between all three parameters. SBP and CI (R 0.466, R 2 0.220; Panel-B), CI and lactate (R -0.228, R 2 0.052; Panel-C), as well as SBP and lactate (R -0.314, R 2 0.098; Panel-D) criteria predominantly identified different patient cohorts, with minimal overlap; demonstrating that these parameters cannot be used interchangeably. Conclusion: Our study is the first to describe poor congruity between the current parameters defining CS. Such limitations raise the need of objectively defining CS so that these high-risk patients can be identified early in the course of CS (pre-CS state), where timely interventions are likely to improve the outcomes.