TY - JOUR
T1 - Major Haemorrhage during Vitamin K Antagonist Treatment: The Influence of Thyroid Hormone Levels
AU - Debeij, Jan
AU - Cannegieter, Suzanne C.
AU - van Zaane, Bregje
AU - van Zanten, Anton P.
AU - Rosendaal, Frits R.
AU - Gerdes, Victor E. A.
AU - Reitsma, Pieter H.
AU - Dekkers, Olaf M.
PY - 2014
Y1 - 2014
N2 - Annually, approximately 1-3% of patients treated with vitamin K antagonists (VKA) suffer from major haemorrhage. Since high levels of free thyroxine (fT4) are associated with increased thrombosis risk, the aim was to assess whether low levels of fT4 contribute to major haemorrhage in patients under VKA treatment. 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 fT4 levels with major haemorrhage were calculated for different fT4 cutoffs by conditional logistic regression. In patients with an fT4 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 fT4 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 fT4 did not affect bleeding risk. No clear effect of thyroid-stimulating hormone and thyroid peroxidase antibodies was seen on the risk of major haemorrhage. These results indicate that fT4 levels below 14 pmol/l play a role in the aetiology of major haemorrhage in VKA users
AB - Annually, approximately 1-3% of patients treated with vitamin K antagonists (VKA) suffer from major haemorrhage. Since high levels of free thyroxine (fT4) are associated with increased thrombosis risk, the aim was to assess whether low levels of fT4 contribute to major haemorrhage in patients under VKA treatment. 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 fT4 levels with major haemorrhage were calculated for different fT4 cutoffs by conditional logistic regression. In patients with an fT4 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 fT4 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 fT4 did not affect bleeding risk. No clear effect of thyroid-stimulating hormone and thyroid peroxidase antibodies was seen on the risk of major haemorrhage. These results indicate that fT4 levels below 14 pmol/l play a role in the aetiology of major haemorrhage in VKA users
U2 - https://doi.org/10.1159/000357578
DO - https://doi.org/10.1159/000357578
M3 - Article
C2 - 24847463
SN - 2235-0640
VL - 3
SP - 32
EP - 37
JO - European thyroid journal
JF - European thyroid journal
IS - 1
ER -