NCT03714048: OBLEX

Blood Management During ECMO for Cardiac Support

Completed Last updated 20 April 2023

What this trial tests

trial in Death, Sudden, Cardiac in 561 participants. Completed in 15 April 2023.

Timeline

1 July 2019

Primary endpoint
15 January 2023

15 April 2023

Quick facts

Lead sponsor	St Vincent's Hospital, Sydney
Status	Completed
Study type	OBSERVATIONAL
Enrollment	561
Start date	1 July 2019
Primary completion	15 January 2023
Estimated completion	15 April 2023
Sites	1 location across Australia

Conditions studied

• Death, Sudden, Cardiac — all drugs for Death, Sudden, Cardiac →
• HEART ARREST — all drugs for HEART ARREST →
• Shock, Cardiogenic — all drugs for Shock, Cardiogenic →
• Arrhythmias, Cardiac — all drugs for Arrhythmias, Cardiac →

Sponsor

St Vincent's Hospital, Sydney

Who can join

18 and older, any sex, with Death, Sudden, Cardiac or HEART ARREST. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Extracorporeal membrane oxygenation (ECMO) is a lifesaving procedure used to treat severe forms of heart and/or lung failure. It works by the principal of replacing the function of these organs by taking blood from the patient, provide it with oxygen outside the body and return it to the patient in one continuous circuit. Because of the evaluability of better technology, the use of ECMO has exponentially risen over the last decade. This treatment is very invasive and carries a number of risks. It is mostly used in situations where it seems likely that the patient would otherwise die and no other less invasive measure could change this. Still in large registries 50-60% of patients die which is often due to complications associated with the treatment.

One of the most important complication is caused by the activation of clotting factors during the contact with the artificial surfaces of the device. This can lead to clot formation inside the patient or the device. To counterbalance this anticoagulation is needed. Because of the consumption of clotting factors and the heparin therapy bleeding complications are also very common in ECMO.

Clinicians are challenged to balance these competing risks and are often forced to transfuse blood products to treat these conditions, which comes with additional risks for the patient. Many experienced centres have reported thromboembolic and bleeding events as the most important contributor to a poor outcome of this procedure. However, no international study combining the experience of multiple centres to compare their practice and identify risk factors which can be altered to reduce these risks.

This study has been endorsed by the international ECMONet and aims to observe the practice in up to 50 centres and 500 patients worldwide to generate the largest ever published database on this topic. It will concentrate on patients with severe heart failure and will be able to identify specific risk factors for thromboembolic and bleeding events. Some of these factors may be modifiable by change in practice and can subsequently be evaluated in clinical trials. Some of these factors may include target values for heparin therapy and infusion of clotting factors.

This study will directly improve patient management by informing clinicians which measures are associated with the best outcome and indirectly helps building trials to increase the evidence further.

Publications & conference data

4 peer-reviewed publications reference this trial (live from Europe PMC):

1. A Systematic Literature Review of Packed Red Cell Transfusion Usage in Adult Extracorporeal Membrane Oxygenation.
   Hughes T, Zhang D, Nair P, Buscher H. · · 2021 · cited 15× · PMID 33808419 · DOI 10.3390/membranes11040251
2. Liberal or restrictive transfusion for veno-arterial extracorporeal membrane oxygenation patients: a target trial emulation using the OBLEX study data.
   Thao LTP, Buscher H, Nguyen TL, Martucci G, et al · · 2025 · cited 2× · PMID 40826421 · DOI 10.1186/s13054-025-05606-1
3. Liberal or restrictive transfusion for veno-arterial Extracorporeal Membrane Oxygenation patients: a target trial emulation using the OBLEX study data
   Le TTP, Buscher H, Nguyen T, Martucci G, et al · · 2025 · cited 1× · DOI 10.21203/rs.3.rs-6241374/v1
4. Major haemorrhage and blood product utilisation in patients receiving VA ECMO for cardiogenic shock: a multicentre observational study (OBLEX).
   Buscher H, Thao LTP, Martucci G, Gratz J, et al · · 2026 · PMID 41814336 · DOI 10.1186/s13054-026-05900-6