Certain HRT pills are linked to increased risk of heart disease and blood clots

Certain hormone replacement therapy (HRT) tablets containing both estrogen and progestogen have been associated with a risk of heart disease and a rare but serious blood clot known as venous thromboembolism (VTE) in perimenopausal women. The results of a study published in Sweden revealed that BMJ today.

Another HRT pill called Tibolone was associated with an increased risk of heart disease, heart attack, and stroke, but not with blood clots. This “highlights the diverse effects that different hormone combinations and administration methods have on cardiovascular disease risk,” the researchers said.

HRT is used to relieve menopausal symptoms such as hot flashes and night sweats, and a variety of treatments are available depending on the symptoms.

Although several previous trials have suggested an association between menopausal hormone therapy and an increased risk of cardiovascular disease, there is a lack of information regarding the risks associated with different types of treatments during the menopausal transition. There is.

To address this, researchers set out to assess the effect of modern menopausal hormone therapy on cardiovascular disease risk, depending on route of administration and hormone combination.

Their findings were based on 138 emulated trials (clinical trials) involving 919,614 healthy Swedish women aged 50 to 58 who had not used hormone therapy in the previous two years between 2007 and 2020. Based on data from a simulated observational study). Women with a history of heart disease, stroke, arterial narrowing, cancer, or who had undergone surgery to remove the ovaries, hysterectomy, or sterilization were excluded.

Using monthly prescription records, women were assigned to one of eight menopausal hormone treatment groups: oral combination continuous therapy, oral combination sequential therapy, oral unopposed estrogen therapy, and oral estrogen plus topical progestin therapy. , no tibolone therapy, transdermal combination therapy, transdermal unopposed estrogen therapy, or menopausal hormone therapy.

Cardiovascular events were then tracked for two years using hospital records, and other potentially influencing factors such as age, education level, region of residence, hypertension, and diabetes were also taken into account.

During this monitoring period, 24,089 cardiovascular events were recorded among the 919,614 women enrolled in the study.

Compared with not starting menopausal hormone therapy, starting oral combination therapy or tibolone was associated with an increased risk of ischemic heart disease. This translates into approximately 11 new cases of ischemic heart disease for every 1,000 women who start treatment with oral combination therapy or tibolone in one year.

Transdermal treatments such as skin patches, gels, and creams did not increase the risk of cardiovascular disease.

An increased risk of blood clots was also found with oral combination continuous therapy, oral combination sequential therapy, oral unopposed estrogen therapy, and transdermal combination therapy. “If 1,000 women started each of these treatments and were followed for 1 year, we would expect to see seven new cases of venous thromboembolism in the entire group,” the authors said.

Tibolone was also associated with an increased risk of stroke and heart attack, but not with blood clots.

Because these are observational results, firm conclusions about causality cannot be drawn, and the authors suggest that lack of data on menopausal status and other unmeasured factors, such as smoking and BMI, may have influenced the results. It points out the limits of possibility. .

However, the use of emulated targeted trial designs reduces biases common to observational studies, and the use of registry data distinguishes between different types of hormone therapy, including differences in dosage, regimen, and hormone combinations. Now you can.

“These findings therefore highlight the diverse effects that different hormone combinations and administration methods have on cardiovascular disease risk,” the researchers wrote.

They added that future studies should investigate potential different effects on cardiovascular disease risk based on the different progestogens used in menopausal hormone therapy.