P5739Venoarterial Extracorporeal Membrane Oxygenation in Cardiogenic Shock: exploring prognostic variables and risk prediction tools

Introduction

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) to support patients in cardiogenic shock has been increasing in Portugal over the past few years. Nonetheless, epidemiologic, prognostic and clinical outcome data are scarce.

Purpose

We aim to identify clinical variables with prognostic significance in this challenging population, as well as the performance of various risk scores in mortality prediction.

Methods

All patients that underwent VA-ECMO support at our Cardiac ICU between 2011 and 2018 were included in the analysis. Logistic regression analysis was used to assess the relationship between clinical variables and outcomes.

Results

Short-term mechanical support with VA-ECMO was given to 40 patients, with a mean age of 52±11 years. At the time of the implant, the mean SOFA score was 11.2±4.0, and mean SAVE score was −4.75±4.6. Mean ECMO support duration was 116±96 hours. In 70% (N=28) of patients, VA-ECMO was successfully weaned. In-hospital mortality was observed in 52.5% of patients, which was in accordance with the predicted mortality by SOFA score (22.5% to 82% in our population risk range) and by SAVE score (60 to 70%). Those who placed the VA-ECMO as a bridge to transplant or to long-term mechanical LV assist device had greater in-hospital mortality rates (91.6 vs 41.9%, p=0.013), as well as those under ≥2 inotropic/vasopressors (69.2 vs 21.4%, p=0.012) or when adrenaline use was needed (100% vs 44.1%, p=0.01). No other between-group differences were observed in what concerns short-term mortality. After logistic regression analysis, independent predictors of in-hospital mortality included AMI setting, number of vasoactive amines used, and necessity of a LV venting device. SAVE score had the greater predictive ability in these patients (AUC = 0.638) among the most utilized clinical risk scores (SOFA score AUC = 0.37; APACHE II score AUC = 0.59; SAPS II score AUC = 0.54).

Conclusion

In our analysis, patients in profound cardiogenic shock on VA-ECMO support had slightly better survival rates than predicted by classical Risk Scores. The SAVE score may be the most accurate tool to predict in-hospital mortality in this specific, and yet heterogeneous, clinical subset. Other well recognized clinical markers of severity may also help refine short-term prognosis, and potentially improve organ transplant or other destination therapy prioritization.