Jan Debeij1, Suzanne C Cannegieter2, Bregje van Zaane3, Anton P van Zanten4, Frits R Rosendaal5, Victor E A Gerdes3, Pieter H Reitsma6, Olaf M Dekkers7. 1. Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands. 2. Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands ; Department of Thrombosis and Haemostasis, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands. 3. Department of Internal Medicine, Slotervaart Hospital, Amsterdam, The Netherlands ; Department of Vascular Medicine, Academic Medical Centre, Amsterdam, The Netherlands. 4. Department of Clinical Biochemistry, Slotervaart Hospital, Amsterdam, The Netherlands. 5. Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands ; Department of Thrombosis and Haemostasis, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands ; Department of Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands. 6. Department of Thrombosis and Haemostasis, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands ; Department of Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands. 7. Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands ; Department of Endocrinology and Metabolism, Leiden University Medical Centre, Leiden, Amsterdam, The Netherlands.
Abstract
BACKGROUND: 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. 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 fT4 levels with major haemorrhage were calculated for different fT4 cutoffs by conditional logistic regression. RESULTS: 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. CONCLUSIONS: These results indicate that fT4 levels below 14 pmol/l play a role in the aetiology of major haemorrhage in VKA users.
BACKGROUND: 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. 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 fT4 levels with major haemorrhage were calculated for different fT4 cutoffs by conditional logistic regression. RESULTS: 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. CONCLUSIONS: These results indicate that fT4 levels below 14 pmol/l play a role in the aetiology of major haemorrhage in VKA users.
Entities:
Keywords:
Coagulation; Epidemiology; Free thyroxine; Haemorrhage; Vitamin K antagonists
Authors: J Debeij; S C Cannegieter; B VAN Zaane; J W A Smit; E P M Corssmit; F R Rosendaal; J A Romijn; O M Dekkers Journal: J Thromb Haemost Date: 2010-12 Impact factor: 5.824
Authors: Nicolas Rodondi; Wendy P J den Elzen; Douglas C Bauer; Anne R Cappola; Salman Razvi; John P Walsh; Bjørn O Asvold; Giorgio Iervasi; Misa Imaizumi; Tinh-Hai Collet; Alexandra Bremner; Patrick Maisonneuve; José A Sgarbi; Kay-Tee Khaw; Mark P J Vanderpump; Anne B Newman; Jacques Cornuz; Jayne A Franklyn; Rudi G J Westendorp; Eric Vittinghoff; Jacobijn Gussekloo Journal: JAMA Date: 2010-09-22 Impact factor: 56.272
Authors: Laura P B Elbers; Hjalmar A Boon; Maaike I Moes; Bregje van Zaane; Dees P M Brandjes; Eric Fliers; Harry R Büller; Suzanne Cannegieter; Victor E A Gerdes Journal: Eur Thyroid J Date: 2016-06-14