Objective

To assess the risk of further thrombosis with using HRT containing transdermal estradiol in women with a personal history of venous thromboembolism (VTE) or arterial thromboembolism (ATE).

Methods

We undertook analysis of patients with a history of VTE/ATE who had been seen in the menopause clinic at King’s College Hospital. They were followed up for a minimum of a 12 months period to assess for recurrence of VTE/ATE.

Results

The study included 115 patients with a personal history of VTE/ATE who had used HRT for over a year. 81% had a history of a VTE, 19% had suffered from an ATE. Patients had taken HRT containing transdermal estradiol +/− micronised progesterone or Mirena coil or combined transdermal HRT for a range of 1–20 years, with an average duration of 3 years. 11 patients had switched from oral HRT to transdermal HRT after visiting the clinic. All patients had been referred to a haematologist with 20% of patients requiring life-long anticoagulation based on their medcial background history. 64% of the patients had documented thrombophilia results with 42% of those being positive for a thrombophilia. 39/115 patients required a higher dose of estrogen, taking either more than two pumps of gel/spray or >50 micrograms in the form of a patch. Significantly on follow up (up to 12 months or more), none of the patients had a recurrence of a thromboembolism within 12 months of starting HRT containing transdermal estradiol.

Conclusion

To our knowledge, this is the first study assessing the use of HRT containing transdermal estradiol in women with a personal history of VTE/ATE. None of the patients assessed had a thromboembolic event within 12 months of follow up. This study will enable more clinicians to consider prescribing HRT in patients with a personal history of VTE/ATE and higher patient uptake, after individualised risk-assessments.