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Haemostatic Markers in Cardiopulmonary Bypass

NCT03861286 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 30

Last updated 2019-09-25

No results posted yet for this study

Summary

This study is to understand the changes occurring in a blood clotting protein, von Willebrand factor (VWF), in patients undergoing cardiac surgery who receive the blood thinner called Heparin. These patients are given Heparin through their veins, to prevent blood clot formation as it passes through the heart bypass machine. At the end of the operation, the effect of Heparin is reversed by another drug, Protamine Sulphate.

Heparin prevents blood clots forming mainly by inactivating thrombin, a crucial protein needed for blood clotting. This effect of Heparin is monitored through blood tests called the 'Anti Factor-Xa' and the 'APTT'.

Heparin has another effect on clotting: it can block the attachment of special blood cell fragments called platelets to damaged blood vessels, but this effect is not usually measured.

Following blood vessel injury, the large VWF sticks to the damaged surface and captures platelets to form a 'plug' which stops bleeding. The platelet plug is then stabilised by other clotting proteins. This stops blood loss and allows vessel repair underneath.

Heparin blocks the ability of VWF to capture platelets at the site of blood vessel injury. The higher the dose of Heparin, the greater this blocking effect is. This secondary effect of Heparin cannot be readily monitored and may explain why bleeding complications occur in patients receiving Heparin despite the monitoring with blood tests used.

This study will look at the blood levels of Heparin, VWF and platelets before, during and after surgery and how well VWF functions in the presence of heparin, including its ability to attach to platelets.

The investigators will determine if all of the heparin related changes in blood clotting can be detected using a method that looks at all of the different steps in forming a blood clot.

Conditions

  • Unfractionated Heparin
  • Cardiopulmonary Bypass Surgery

Sponsors & Collaborators

  • Royal Brompton & Harefield NHS Foundation Trust

    collaborator OTHER

  • Imperial College London

    lead OTHER

Principal Investigators

  • Deepa Arachachillage, MBBS · Imperial College London

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2019-02-15
Primary Completion
2019-07-18
Completion
2019-07-18

Countries

  • United Kingdom

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT03861286 on ClinicalTrials.gov