The Women’s Health Initiative (WHI) included two large clinical trials that evaluated whether hormone therapy with oestrogen reduces the risk of coronary heart disease in postmenopausal women, according to background information in the article. In the part of the study designed to test oestrogen therapy alone, 10,739 women aged 50 to 79 years who had undergone hysterectomy were assigned to take either conjugated equine oestrogens or a placebo. Though researchers had planned to study the women for 8.5 years, the oestrogen-only trial was stopped in March 2004 after only 6.8 years because the hormone treatment appeared to increase the risk of stroke.

Judith Hsia, M.D., of George Washington University, Washington, D.C., and colleagues analysed data from the oestrogen-only portion of the WHI study. During the course of the trial, the women taking hormones experienced 201 coronary events, which included heart attacks and coronary deaths, while those taking placebo had 217 events. Overall, the risk was similar for women who took hormones compared with those who did not, though there was a suggestion of lower risk in women age 50 to 59 years.

Among these women - a total of 1,396 - who were aged 50 to 59 years at the start of the study, there was no significant reduction in myocardial infarction or coronary death among those taking oestrogen. However, coronary revascularisation was less frequent among women taking oestrogen, as were several combined endpoints, such as myocardial infarction, coronary death and revascularisation. “This trial may have been unable to demonstrate a significant difference in the risk of myocardial infarction or coronary death by age group because of the low event rate in young women,” the authors report.

MEDICA.de; Source: American Medical Association (AMA)