Recurrent venous thromboembolism and abnormal uterine bleeding with anticoagulant and hormone therapy use

Blood. 2016 Mar 17;127(11):1417-25. doi: 10.1182/blood-2015-08-665927. Epub 2015 Dec 22.

Abstract

Women receiving vitamin K antagonists (VKAs) require adequate contraception because of the potential for fetal complications. It is unknown whether the use of hormonal therapy, especially those containing estrogens, is associated with recurrent venous thromboembolism (VTE) during anticoagulation. Despite the absence of data, World Health Organization guidelines state that use of estrogen-containing contraceptives confers an "unacceptable health risk" during established anticoagulation for VTE. We compared the incidences of recurrent VTE and abnormal uterine bleeding with and without concomitant hormonal therapy in women aged <60 years who were receiving anticoagulation with rivaroxaban or enoxaparin/VKA for confirmed VTE. Incidence densities in percentage per year were computed for the on and off estrogen-containing or progestin-only therapy periods. Cox regression models were fitted, with hormonal therapy (on vs off) as a time-dependent variable to derive the hazard ratio (HR) for the effects on recurrent VTE and abnormal uterine bleeding. In total, 1888 women were included. VTE incidence densities on and off hormonal therapy were 3.7%/year and 4.7%/year (adjusted HR, 0.56; 95% confidence interval [CI], 0.23-1.39), respectively, and were 3.7%/year and 3.8%/year, respectively, for estrogen-containing and progestin-only therapy. The adjusted HR for all abnormal uterine bleeding (on vs off hormonal therapy) was 1.02 (95% CI, 0.66-1.57). Abnormal uterine bleeding occurred more frequently with rivaroxaban than with enoxaparin/VKA (HR, 2.13; 95% CI, 1.57-2.89). Hormonal therapy was not associated with an increased risk of recurrent VTE in women receiving therapeutic anticoagulation. The observed increased risk of abnormal uterine bleeding with rivaroxaban needs further exploration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anticoagulants / adverse effects*
  • Contraceptives, Oral, Hormonal / adverse effects
  • Drug Synergism
  • Enoxaparin / adverse effects*
  • Enoxaparin / therapeutic use
  • Estrogen Replacement Therapy / adverse effects
  • Estrogens / adverse effects*
  • Estrogens / therapeutic use
  • Female
  • Humans
  • Middle Aged
  • Progestins / adverse effects*
  • Progestins / therapeutic use
  • Proportional Hazards Models
  • Randomized Controlled Trials as Topic
  • Recurrence
  • Retrospective Studies
  • Rivaroxaban / adverse effects*
  • Rivaroxaban / therapeutic use
  • Uterine Hemorrhage / chemically induced*
  • Uterine Hemorrhage / epidemiology
  • Venous Thromboembolism / chemically induced*
  • Venous Thromboembolism / epidemiology
  • Venous Thromboembolism / prevention & control
  • Young Adult

Substances

  • Anticoagulants
  • Contraceptives, Oral, Hormonal
  • Enoxaparin
  • Estrogens
  • Progestins
  • Rivaroxaban