The heparin-von Willebrand factor interaction and conventional tests of haemostasis - the challenges in predicting bleeding in cardiopulmonary bypass
File(s)
Author(s)
Type
Journal Article
Abstract
Bleeding is a significant complication of cardiopulmonary bypass (CPB), despite routine anticoagulation monitoring. This is likely to be multifactorial. In this prospective, single‐centre cohort study of 30 patients undergoing CPB surgery, our aim was to characterise the changes in von Willebrand factor (VWF) function, platelet interaction and the global coagulation changes during and after CPB surgery and to determine whether bleeding can be predicted. Samples were taken at six time points before, during and after CPB surgery. We observed a significant rise in VWF antigen (VWF:Ag) throughout surgery, which continued postoperatively. The absolute VWF collagen‐binding assays (VWF:CB) and VWF ristocetin cofactor (VWF:RCo) rose significantly but the VWF:CB/VWF:Ag and VWF:Ag/VWF:RCo fell significantly (P = 0·0015 and P = 0·0143), suggesting loss of large multimers. We detected a non‐significant trend to loss of VWF:RCo after heparinisation and a significant recovery after protamine reversal which could reflect a direct heparin effect. There was a significant increase in the R and K times with a fall in alpha angle and maximum amplitude after heparin administration, using heparinase‐thromboelastography (TEG). The parameters both significantly improved following protamine (P = 0·007 and P = 0·0054). The activated clotting time (ACT) and heparin anti‐Xa level correlated poorly; neither predicted clinically significant bleeding. None of these parameters had a relationship with intraoperative blood loss or requirement for blood product replacement.
Date Issued
2021-03
Date Acceptance
2020-11-13
Citation
British Journal of Haematology, 2021, 192 (6), pp.1073-1081
ISSN
0007-1048
Publisher
Wiley
Start Page
1073
End Page
1081
Journal / Book Title
British Journal of Haematology
Volume
192
Issue
6
Copyright Statement
© 2020 British Society for Haematology and John Wiley & Sons Ltd. This is the accepted version of the following article: Ranger, A., Gaspar, M., Elkhatteb, A., Jackson, T., Fox, S., Aw, T.C., Vipond, L., Cotterill, J., Ghori, A., Laffan, M. and Arachchillage, D.R.J. (2021), The heparin‐von Willebrand factor interaction and conventional tests of haemostasis – the challenges in predicting bleeding in cardiopulmonary bypass. Br J Haematol, which has been published in final form at https://doi.org/10.1111/bjh.17263
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000595670300001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Hematology
cardiopulmonary bypass
unfractionated heparin
von Willebrand factor
bleeding
thromboelastography
activated clotting time
PROTAMINE SULFATE
FACTOR-VIII
INHIBITION
AFFINITY
SURGERY
BINDING
Publication Status
Published
Date Publish Online
2020-12-05