Heavy MEnstrual bleeding in premenopausal women treated with DirEct oral Anticoagulants - the MEDEA study

Treatment with direct oral anticoagulants (DOACs), in particular factor Xa inhibitors, is associated with an increased risk of abnormal uterine bleeding, particularly heavy menstrual bleeding (HMB), in premenopausal women. It has been suggested that abnormal uterine bleeding, including HMB and intermenstrual bleeding, occurs less frequently during treatment with the thrombin inhibitor dabigatran. The association between the type of DOACs (factor Xa versus thrombin inhibitor) and HMB has not been fully elucidated and merely assumptions on possible mechanisms exist. Use of tranexamic acid during the menstrual period may be effective in patients with HMB, but prospective data regarding efficacy and safety in patients with an indication for anticoagulant treatment are lacking. DOACs are prescribed increasingly and a direct comparison between dabigatran and a factor Xa inhibitor, as well as an evaluation of the effects of additional tranexamic acid in women with HMB is highly relevant for clinical practice. All available methods to measure menstrual blood loss have limitations, but the pictorial blood loss assessment chart (PBAC) is a simple clinical tool and has adequately been validated as a semi-objective assessment of menstrual blood loss and pattern of menstrual cycle.
The disease specific menstrual bleeding questionnaire (MBQ) is a valid patient-reported outcome measure for heavy menstrual bleeding.

A switch to thrombininhibitor dabigatran or addition of tranexamic acid to the factor Xa inhibitor may be effective in women who experience heavy menstrual bleeding during anticoagulant treatment with factor Xa inhibitors.

* Screening
* Enrolment/Visit 1
* 1 month - visit 2 (telephone)
* 2 months - visit 3 (telephone)
* End of Study - visit 4

Eligible patients will be randomised in a 1:1:1 ratio to switch to dabigatran, to continue treatment with the factor Xa inhibitor without intervention, or to continue treatment with the factor Xa inhibitor with the addition of 1 gram tranexamic acid three times a day during the first four days of the menstrual period.