OC 67.1 - Antithrombin deficiency and altered heparin responsiveness during veno-arterial extracorporeal life support: a prospective study

Tuesday, July 12, 2022

2:45 PM – 3:00 PM

Location: ExCel Center, ICC Capital Suite Room 2-4

Presentation Format: Virtual

Presenting Author(s)

Alexandre Mansour, MD

Anesthesiologist-intensivist
Cardiothoracic Intensive Care Unit, Department of Anesthesia Cardiothoracic Intensive Care Unit, Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, Institut de recherche en santé, environnement et travail - IRSET, Inserm UMR_S 1085, Univ Rennes, CHU Rennes, France 1085, Univ Rennes, CHU Rennes, France
Rennes, Bretagne, France

Co-Author(s)

MB

Mathilde Berahou

Anesthesiologist-intensivist
Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
JO

Joscelyn Odot

Anesthesiologist-intensivist
Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
AP

Adeline Pontis

Clinical Pathologist
Department Biological Hematology, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
FN

Fabienne Nedelec-Gac

PharmD
Department of Hematology/Hemostasis, Pontchaillou University Hospital of Rennes, Rennes, France
Rennes, Bretagne, France
AP

Alessandro Parasido

Cardiovascular perfusionist
Department of Cardiothoracic surgery, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
FR

Florian Reizine

Intensivist
Service des maladies infectieuses et r animation m dicale, Rennes University Hospital, Rennes, France
Rennes, Bretagne, France
YL

Yoann Launey

Anesthesiologist-intensivist
Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
AO

Ahmad Ousmen

Statistician
epidemiology biostatistics and occupational health, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
RG

Ronan Garlantezec

Professor
epidemiology biostatistics and occupational health, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
EF

Erwan Flecher

Professor of Cardiothoracic Surgery
Department of Cardiothoracic surgery, Pontchaillou, University Hospital of Rennes, CHU Rennes, France
Rennes, Bretagne, France
NN

Nicolas Nesseler

Anesthesiologist-intensivist
Cardiothoracic Intensive Care Unit, Department of Anesthesia and Critical Care, Pontchaillou, University Hospital of Rennes, Univ Rennes, CHU Rennes, France
Rennes, Bretagne, France
Isabelle Gouin-Thibault, Sr., PhD

Head of hemostasis department
Department of Hematology/Hemostasis, Pontchaillou University Hospital of Rennes, Univ Rennes, Irset - Inserm UMR_S 1085, Rennes, France.
Rennes, Bretagne, France

Background: During VA-ECLS, unfractionated heparin (UFH) is administered to prevent hemocompatibility-related adverse events. Antithrombotic properties of UFH rely on plasma antithrombin (AT) activity. Given the underlying critical illness and blood exposure to shear stress and non-biological surfaces, coagulopathy including decreased AT levels and apparent altered heparin responsiveness (AHR) are frequently associated with thrombosis and bleeding. While there is currently no evidence of a beneficial effect on heparin responsiveness or adverse events, AT supplementation is routinely administered during ECLS.

Aims: 1) Determine dynamic changes of plasma AT levels during the first week of ECLS support
2) Evaluate the association between AT deficiency and AHR

Methods: Adults receiving VA-ECLS were prospectively included (CHU Rennes, France). All patients received UFH using a standardized protocol (target anti-FXa 0.3-0.5IU.mL-1). For each patient, arterial blood was withdrawn on citrated tubes, at 11 time-points (H0 at ECMO initiation, H+2, H+6, H+12, H+24 and daily up to D7). Anti-FXa activity and AT level were measured (STA Liquid anti-Xa®, Stachrom AT®; Stago). Data regarding clinical management and heparin dosage were collected. A new index was created to evaluate heparin responsiveness (HRI-Heparin Responsiveness Index) measured at each time-points as follows: HRI=heparin dosage [IU.kg-1.h-1] / anti-FXa activity [IU.mL-1].

Results: Fifty patients including 42% post-cardiotomy ECMO were included between April 2020 and May 2021, with a total of 403 samples. Median ECMO duration was 7 days (IQR 4-12). Median AT level was 48% (37-60) at H0. AT levels significantly increased throughout the follow-up, without any supplementation (Figure 1). Overall, 49(98%) patients had at least one AT value below 80%, 45(90%) below 70% and 35(70%) below 50%. AT level was not correlated to heparin responsiveness evaluated by anti-FXa activity, heparin dosage or HRI (r=0.04, p=0.57; Figure 2).

Conclusion(s): Antithrombin deficiency is common during the first 72 hours of VA-ECMO support and is not related to altered heparin responsiveness.