Major Haemorrhage during Vitamin K Antagonist Treatment: The Influence of Thyroid Hormone Levels
Background: Annually, approximately 1-3% of patients treated with vitamin K antagonists (VKA) suffer from major haemorrhage. Since high levels of free thyroxine (fT 4 ) are associated with increased thrombosis risk, the aim was to assess whether low levels of fT 4 contribute to major haemorrhage in...
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Published in | European thyroid journal Vol. 3; no. 1; pp. 32 - 37 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Basel, Switzerland
S. Karger AG
01.03.2014
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Subjects | |
Online Access | Get full text |
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Summary: | Background: Annually, approximately 1-3% of patients treated with vitamin K antagonists (VKA) suffer from major haemorrhage. Since high levels of free thyroxine (fT 4 ) are associated with increased thrombosis risk, the aim was to assess whether low levels of fT 4 contribute to major haemorrhage in patients under VKA treatment. Methods: The FACTORS (Factors in Oral Anticoagulant Safety) study is a case-control study on patients receiving VKA treatment, including 110 cases with major haemorrhage. Controls were 220 matched participants treated with VKA without major haemorrhage. Odds ratios (OR) and 95% confidence intervals (95% CI) for the association of fT 4 levels with major haemorrhage were calculated for different fT 4 cutoffs by conditional logistic regression. Results: In patients with an fT 4 level below 13 pmol/l, the risk of major haemorrhage was 5-fold increased (OR = 5.1; 95% CI: 0.9-28.6) compared with patients with an fT 4 level above 13 pmol/l. At a cutoff of 14 pmol/l, the risk was 3-fold increased (OR = 2.9; 95% CI: 1.0-8.5). High levels of fT 4 did not affect bleeding risk. No clear effect of thyroid-stimulating hormone and thyroid peroxidase antibodies was seen on the risk of major haemorrhage. Conclusions: These results indicate that fT 4 levels below 14 pmol/l play a role in the aetiology of major haemorrhage in VKA users. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2235-0640 2235-0802 |
DOI: | 10.1159/000357578 |