Research Highlights:
- A large, long-term study of over 52,000 women in Israel found that among women ages 45 to 59, initiation of contemporary hormone replacement therapy did not increase the risk of heart attack, stroke, blood clots or death.
- The independent, preliminary study had an average follow-up of 12 years and included hormone replacement therapy in oral, transdermal (patch) or gel form.
- Note: The study featured in this news release is a research abstract. Abstracts presented at American Heart Association's scientific meetings are not peer-reviewed, and the findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
DALLAS, Nov. 2, 2026 — Contemporary hormone replacement therapy (HRT) was not associated with an increased risk for heart attack, stroke, blood clots or death among women ages 45 to 59, according to a large, long-term study of over 52,000 women in Israel. The findings from this new, independent, preliminary research will be presented at the American Heart Association's Scientific Sessions 2026. The meeting, Nov. 6-9, in Chicago, is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science.
"Concerns that hormone replacement therapy may affect the heart is one of the most common reasons women decline hormone therapy to manage menopause symptoms, and why some healthcare professionals may hesitate to offer it," said lead study researcher Ronen Arbel, Ph.D., a researcher in the community medical services division of Clalit Health Services in Tel Aviv, Israel, and a researcher with Sapir College's Maximizing Health Outcomes Research Lab in Sderot, Israel.
Previous randomized trials found associations between HRT and cardiovascular harm. However, results were mixed, and much of that evidence was from studies with older HRT formulations that are no longer commonly used, with higher doses and in women who started on HRT long after menopause. Current clinical guidelines from the American College of Obstetricians and Gynecologists recommend starting HRT within 10 years of menopause onset and before age 60. In November 2025, the FDA removed the "black box" warnings from HRT products after a comprehensive review of current scientific data indicating that HRT is not associated with increased risk of cardiovascular disease, breast cancer or dementia.
"For many women, menopause symptoms can significantly affect their quality of life, yet questions about the cardiovascular safety of hormone therapy have remained," said Stacey E. Rosen, M.D., FAHA, an expert in women's heart health and past volunteer president of the American Heart Association (2025-2026). "This large, long-term study adds to growing evidence that today's hormone therapy options may not increase the risk of heart disease, stroke or blood clots for healthy women who begin treatment around the time of menopause. These findings can help women and their healthcare teams have more informed conversations about the benefits and risks of treatment based on their individual health needs." Rosen, who was not involved in this study, is also executive director of the Katz Institute for Women's Health and senior vice president of women's health at Northwell Health in New York City.
The study to be presented at the American Heart Association's Scientific Sessions evaluated data for over 52,000 women, ages 45 to 59, to assess whether the use of contemporary HRT is associated with an increased risk of atherosclerotic cardiovascular disease, venous thromboembolism (blood clots) or premature death (before age 80) in women who had not been previously diagnosed with cardiovascular disease.
After an average of 12 years of follow-up, the health outcomes were similar between the two groups of women, meaning the group who started taking HRT did not show an increase in cardiovascular events or early death compared to the group that was not taking HRT.
What are the study's main findings?
- 2,311 women in the HRT group (4.4%) experienced a heart attack, stroke or had some type of related heart disease vs. 2,383 (4.6%) of the women in the no-HRT group.
- Death before age 80 occurred in 659 (1.3%) of the women taking HRT vs. 653 (1.2%) of the women not on any form of HRT.
- 0.33% of women in both groups experienced a blood clot (174 women in the group taking HRT vs. 175 from the group that did not take HRT).
- The results were similar across all HRT formulations and administration routes (oral, patch or gel).
"Our results indicate that, for women in their mid-forties to late fifties with no history of heart disease or blood clots, the currently available hormone therapies prescribed to manage menopause symptoms do not appear to raise the risk of heart attack, stroke, clots or early death, even after long-term use," Arbel said.
Study details, background and design:
- Using records from Clalit Health Services in Israel, researchers evaluated health data for 52,330 women between 45–59 years old with no history of heart disease, blood clots or cancer.
- Half of the women had started HRT, primarily via oral and/or transdermal (patch) methods, while the other half had recently visited a gynecologist but did not begin HRT. The women in the second group did not take HRT throughout the study period.
- The researchers matched the women in both groups by age, BMI, cardiometabolic risk factors (blood pressure, cholesterol levels and whether they had been diagnosed with Type 1 or Type 2 diabetes), smoking status and socioeconomic status and compared their health data.
- Researchers evaluated the health records of both groups for up to 23 years, with an average follow-up period of 12 years, to compare the rate of cardiovascular disease, specifically heart attack, stroke and blood clots, as well as death from any cause before age 80.
The research has several limitations. It is an observational study, so it cannot prove a direct connection between HRT and heart health. The researchers also noted that there may be other differences among the women taking HRT vs. those who do not that was not available or detailed in the health records, such as differences in exercise, diet, other health conditions and severity of menopause symptoms. Additionally, the study grouped women by the first type of hormone therapy they used and did not include any changes in HRT type or formulation throughout the follow-up period.
Co-authors, disclosures and funding sources are listed in the abstract.
Statements and conclusions of studies that are presented at the American Heart Association's scientific meetings are solely those of the study authors and do not necessarily reflect the Association's policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association's scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
