The IMPACT Score: A new score to predict the risk of early mortality in cardiogenic shock patients treated with venoarterial extracorporeal membrane oxygenation

Abstract

Abstract Purpose : Venoarterial-ECMO (VA-ECMO) is indicated in the management of refractory cardiogenic shock. There is currently no risk factor for early mortality, i.e. occurring within 72 hours of implantation. Highlighting them could avoid unnecessary recourse to this costly and heavy-care technique. The objective of this study is to determine the risk factors associated with early mortality in patients implanted with VA-ECMO and to construct a prognostic score. Methods: This single-center retrospective study included all patients treated with VA-ECMO at Felix Guyon Hospital in Reunion Island over the period 2014-2020. The pre-implantation risk factors for early mortality were sought by logistic regression and integrated into the IMPACT score. Results: A total of 165 patients were included in the study. Early mortality (<72 hours) was 20% (33 patients). Four pre-implantation risk factors were identified and integrated into the IMPACT score: lactate levels > 8mmol/L (Odds ratio (OR) = 4.2; p = 0.007), platelet count < 100G/L (OR = 4.9; p = 0.022), renal replacement therapy (OR = 7.1; p = 0.001), and cardiac arrest (OR = 3.2; p = 0.036). The IMPACT score had an AUC of 0.80 [95% Confidence Interval 0.73-0.88]. Conclusion: The IMPACT score can help the physicians to identify patients who do not expect any benefit from VA-ECMO. Its validity should be tested in other populations treated with VA-ECMO.