1Deutsches Herzzentrum der Charité (CBF) Klinik für Kardiologie, Angiologie und Intensivmedizin Berlin, Deutschland; 2Copenhagen University Hospital Rigshospitalet Department of Cardiology Copenhagen, Dänemark; 3Aarhus University Hospital, 8200 Aarhus Department of Cardiology Aarhus, Dänemark; 4Odense University Hospital Department of Cardiology, Odense, Dänemark; 5Aalborg University Hospital Department of Anesthesiology and Intensive Medicine, Aalborg, Dänemark; 6University of Southern Denmark Department of Clinical Research, Odense, Dänemark
Background: Extracorporeal cardio-pulmonary resuscitation (ECPR) can be considered in selected patients with refractory cardiac arrest. Given the risk of patient futility and high resource utilisation, identifying ECPR candidates who would benefit from this complex therapy is crucial. Previous ECPR studies investigating lactate as a potential prognostic marker have been small and inconclusive.
Aim: It was hypothesised that the lactate level (immediately prior to initiation of ECPR) and lactate clearance (within 24 hours after ECPR initiation) are predictors of one-year survival in a large, multicentre study cohort of patients receiving ECPR with veno-arterial extracorporeal membrane oxygenation (VA-ECMO).
Methods: The study was performed in adult patients with refractory cardiac arrest at three German and four Danish tertiary cardiac care centres between 2011 and 2021. Pre-ECPR lactate and 24-hour lactate clearance were divided into three equally sized tertiles. Multivariable logistic regression analyses and Kaplan-Meier analyses were used to analyse survival outcomes.
Results: 297 adult patients with refractory cardiac arrest were included in this study, of which 65 (22%) survived within one year. The pre-ECPR lactate level and 24-hour lactate clearance were dose-dependently associated with one-year survival: OR 5.40 [95% CI 2.30-13.60] for lowest versus highest pre-ECPR lactate level and OR 0.25 [95% CI 0.09-0.68] for lowest vs. highest 24-hour lactate clearance, respectively. Results were confirmed in Kaplan-Meier analyses (each p log rank <0.001; see Figure) and multiple sensitive analyses.
Conclusion: Pre-ECPR lactate levels and 24 hour-lactate clearance after ECPR initiation in patients with refractory cardiac arrest were dose-dependently associated with one-year survival outcomes. Lactate is an easily accessible and quickly available point-of-care measurement which might be considered as an early prognostic marker when considering initiation or continuation of ECPR treatment.