SCAI Shock Classification to Predict Outcomes of Venoarterial Extracorporeal Membrane Oxygenation

Abstract

<h3>Purpose</h3> The Society for Cardiovascular Angiography and Interventions (SCAI) recently introduced a staging schema for cardiogenic shock (CS) based on exam findings, lab markers, and hemodynamics. We applied the SCAI schema to CS patients treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO) to assess clinical relevance. <h3>Methods</h3> We retrospectively reviewed patients receiving VA-ECMO for CS at our institution from January 2015 to December 2019. Patients with post-cardiotomy shock and non-cardiac shock etiologies were excluded. Patients were classified to a SCAI stage A-E based on device and drug initiation, hemodynamics, CPR use, and levels of lactate and creatinine. Outcomes included in-hospital mortality, myocardial recovery, and adverse events during ECMO course. <h3>Results</h3> A total of 245 patients met the inclusion criteria, with median age of 59 years [IQR: 48-67]. One hundred fifty-nine patients (65%) were male. The number of patients in SCAI stages was 0 (0%) in A, 0 (0%) in B, 34 (14%) in C, 82 (33%) in D, and 129 (53%) in E. Of the E patients, 88 (68%) were undergoing CPR. Underlying CS etiologies of acute decompensated heart failure (C: 53%, D: 43%, E: 17%, p<0.001) and ventricular fibrillation (C: 9%, D: 0%, E: 3%, p<0.001) were greater in C. Median ECMO duration decreased with stage (C: 7 [4-14], D: 6 [3-9], E: 4 [1-8] days, p<0.001). In-hospital mortality increased (C: 35%, D: 56%, E: 71%, p<0.001) and myocardial recovery decreased (C: 68%, D: 37%, E: 30%, p<0.001) with stage. Adverse events varied in terms of acute kidney injury (C: 35%, D: 45%, E: 54%, p=0.045) and infection (C: 35%, D: 28%, E: 16%, p=0.004). Kaplan-Meier analysis revealed E had worse survival than C and D (Figure 1). Outcomes were similar between E,CPR+ and E,CPR- patients (68% vs. 73%, p=0.76). <h3>Conclusion</h3> In patients treated with VA-ECMO for CS, the SCAI classification provided robust risk stratification.