From the Guidelines
Risk of DVT in Patients on HRT
The risk of Deep Vein Thrombosis (DVT) in patients on Hormone Replacement Therapy (HRT) is significantly increased, with a 2-fold increased rate of venous thromboembolic disease, including DVT and pulmonary embolism, compared to those not on HRT 1.
Key Findings
- A meta-analysis of 12 studies found that HRT was associated with an increased risk for venous thromboembolism, with a relative risk (RR) of 2.14 (95% CI, 1.64 to 2.81) 1.
- The risk was highest within the first year of use, with an RR of 3.49 (95% CI, 2.33 to 5.59) 1.
- The estrogen and progestin arm of the Women's Health Initiative (WHI) reported a 2-fold increased rate of venous thromboembolic disease, including DVT and pulmonary embolism, in women taking conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) daily 1.
Clinical Implications
- Clinicians should discuss the risks and benefits of HRT with patients, including the increased risk of DVT, and consider alternative therapies for menopausal symptoms and osteoporosis prevention 1.
- Women on HRT should be informed of the signs and symptoms of DVT and pulmonary embolism, and seek medical attention immediately if they experience any of these symptoms.
- The use of HRT for the primary prevention of chronic conditions should be approached with caution, and alternative therapies should be considered 1.
From the Research
Risk of DVT in Patients on HRT
The risk of Deep Vein Thrombosis (DVT) in patients on Hormone Replacement Therapy (HRT) is a significant concern. Several studies have investigated this risk, and the findings are as follows:
- The risk of DVT is increased in women taking HRT, particularly those using oral estrogens 2, 3, 4.
- The risk is higher in women with a history of thrombosis or thrombophilia 3, 5, 6.
- Transdermal estrogens may not confer additional risk in women at high risk for thrombosis 2, 4.
- The combination of oral estrogen use and either obesity or thrombogenic mutations further enhances the VTE risk 2.
- The type of concomitant progestogen also affects the VTE risk, with medroxyprogesterone acetate increasing the risk more than other progestins 2.
- Women who have previously suffered a VTE have an increased risk of recurrence on HRT, and this treatment should be avoided in this patient group if possible 3.
Factors Affecting DVT Risk in HRT Users
Several factors affect the risk of DVT in HRT users, including:
- Route of estrogen administration: oral estrogens increase the risk more than transdermal estrogens 2, 4.
- Type of progestogen: medroxyprogesterone acetate increases the risk more than other progestins 2.
- History of thrombosis or thrombophilia: women with a history of thrombosis or thrombophilia are at higher risk 3, 5, 6.
- Obesity: obesity increases the risk of VTE in women using oral estrogens 2.
- Thrombogenic mutations: women with thrombogenic mutations are at higher risk of VTE when using oral estrogens 2, 5.