Left-ventricular Unloading With Impella® During Refractory Cardiac Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation - A Systematic Review and Meta-analysis.

T. Thevathasan (Berlin)¹, L. Füreder (Berlin)², M. Fechtner (Berlin)², S. R. Mørk (Aarhus)³, B. Schrage (Hamburg)⁴, D. Westermann (Freiburg im Breisgau)⁵, L. Linde (Odense)⁶, E. Gregers (Copenhagen)⁷, J. B. Andreasen (Aalborg)⁸, C. Gaisendrees (Köln)⁹, T. Unoki (Kumamoto City)¹⁰, A. L. Axtell (Boston)¹¹, K. Takeda (New York)¹², A. V. Vinogradsky (New York)¹², P. Gonçalves-Teixeira (Oporto)¹³, A. Lemaire (New Brunswick)¹⁴, M. Alonso-Fernandez-Gatta (Salamanca)¹⁵, H. S. Lim (Birmingham)¹⁶, A. R. Garan (Boston)¹⁷, A. Bindra (Dallas)¹⁸, G. Schwartz (Dallas)¹⁸, U. Landmesser (Berlin)¹⁹, C. Skurk (Berlin)^1
1Charité - Universitätsmedizin Berlin CC 11: Med. Klinik für Kardiologie Berlin, Deutschland; ²Deutsches Herzzentrum der Charité (CBF) Klinik für Kardiologie, Angiologie und Intensivmedizin Berlin, Deutschland; ³Aarhus University Hospital Department of Cardiology Aarhus, Dänemark; ⁴Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Hamburg, Deutschland; ⁵Universitäts-Herzzentrum Freiburg - Bad Krozingen Innere Medizin III, Kardiologie und Angiologie Freiburg im Breisgau, Deutschland; ⁶Odense University Hospital Department of Cardiology, Odense, Dänemark; ⁷Copenhagen University Hospital Department of Cardiology Copenhagen, Dänemark; ⁸Aalborg University Hospital Department of Aneastesiology and Intensive Care Aalborg, Dänemark; ⁹Universitätsklinikum Köln Köln, Deutschland; ¹⁰Saiseikai Kumamoto Hospital Department of Cardiology and Intensive Care Unit Kumamoto City, Japan; ¹¹Massachusetts General Hospital, Harvard Medical School Division of Cardiac Surgery Boston, USA; ¹²Columbia University Medical Center, New York-Presbyterian Hospital Department of Surgery New York, USA; ¹³Centro Hospitalar de Vila Nova de Gaia Department of Cardiology Oporto, Portugal; ¹⁴Rutgers-Robert Wood Johnson Medical School Division of Cardiothoracic Surgery New Brunswick, USA; ¹⁵University Hospital of Salamanca Cardiology Department Salamanca, Spanien; ¹⁶Queen Elizabeth Hospital Birmingham Department of Cardiology Birmingham, Deutschland; ¹⁷Beth Israel Deaconess Medical Center Boston, USA; ¹⁸Baylor University Medical Center Center for Advanced Heart and Lung Disease Dallas, USA; ¹⁹Deutsches Herzzentrum der Charite (DHZC) Klinik für Kardiologie, Angiologie und Intensivmedizin Berlin, Deutschland

Objective: Extracorporeal cardio-pulmonary resuscitation (ECPR) is the implementation of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) during refractory cardiac arrest. The role of left-ventricular (LV) unloading with Impella^® in addition to VA-ECMO (“ECMELLA”) remains unclear during ECPR. This is the first systematic review and meta-analysis to characterize patients with ECPR receiving LV unloading and to compare in-hospital mortality and complications between ECMELLA and VA-ECMO during ECPR.
Data Sources: Medline, Cochrane Central Register of Controlled Trials (CENTRAL), Embase and abstract websites of the three largest cardiology societies (American Heart Association, American College of Cardiology and European Society of Cardiology).
Study Selection: Observational studies with adult patients with refractory cardiac arrest receiving ECPR with ECMELLA or VA-ECMO until July 2023 according to the PRISMA checklist.
Data Extraction: Patient and treatment characteristics, in-hospital mortality and complications from 13 study records at 32 hospitals with a total of 1,014 ECPR patients. Odds ratios (OR) and 95% confidence interval (CI) were computed with the Mantel-Haenszel test using a random-effects model.
Data Synthesis: 762 patients (75.1%) received VA-ECMO and 252 (24.9%) ECMELLA. Compared to VA-ECMO, the ECMELLA group was comprised of more patients with initial shockable ECG rhythms (58.6% vs. 49.3%), acute myocardial infarctions (79.7% vs. 51.5%) and percutaneous coronary interventions (79.0% vs. 47.5%). VA-ECMO alone was more frequently used in pulmonary embolism (9.5% vs. 0.7%). Age, rate of out-of-hospital cardiac arrest and low-flow times were similar between both groups. ECMELLA support was associated with reduced odds of mortality (OR 0.53 [95% CI 0.30-0.91]) and higher odds of good neurological outcome (OR 2.22 [95% CI 1.17-4.22]) compared to VA-ECMO support alone (see Figure). ECMELLA therapy was associated with numerically increased but not significantly higher complication rates. Primary results remained robust in multiple sensitivity analyses.
Conclusions: ECMELLA support was predominantly utilized in patients with acute myocardial infarction and VA-ECMO for pulmonary embolism. ECMELLA support during ECPR might be associated with improved survival and neurologic outcome despite higher complication rates. Though, indications and frequency of ECMELLA support varied strongly between institutions. Further scientific evidence is urgently required to elaborate standardized guidelines for the use of LV unloading during ECPR.