Risk of cardiac and stroke death increases after discontinuing hormone therapy

Since publication of the Women's Health Initiative (WHI) clinical trial data, there has been significant disagreement over the various risks and benefits of HT. What remains relatively unchallenged is the fact that estrogen has rapid beneficial vascular effects and that shorter periods between the onset of menopause and the initiation of HT provide greater protection against cardiovascular disease. This beneficial relationship between HT and protection against heart disease has led to the speculation that withdrawal from HT could result in clinically significant changes in arterial function. Although previous studies have shown that termination of estradiol-based HT led to significant increases in the risk of cardiac and stroke deaths, particularly during the first year, these results were questioned because women with documented heart problems had not been excluded from the study.

This study, however, involving more than 400,000 Finnish women excluded women with prior cardiac or stroke events. The results of the study, published in the article "Increased cardiac and stroke death risk in the first year after discontinuation of postmenopausal hormone therapy," showed that discontinuation of HT was associated with an increased risk of cardiac and stroke death during the first posttreatment year, especially in women who discontinued HT aged younger than 60 years. This increased risk was not observed in women aged 60 years or older at the time of discontinuation.

"Since the initial Women's Health Initiative reports, studies have shown that hormone therapy has many benefits and is safer than originally thought. This is especially true for symptomatic menopausal women younger than age 60 and within 10 years of menopause, as these women had fewer heart events and less risk of mortality," says Dr. JoAnn Pinkerton, NAMS executive director. "This new study suggests that younger women may have a higher risk of heart disease and stroke during the first year of discontinuation. Thus, women and their healthcare providers need to consider the benefits and risks of starting and stopping hormone therapy before making any decisions."