Hot Flashes, HRT, and CVD: Timing Is Everything!

This transcript has been edited for clarity. Hello. This is Dr JoAnn Manson, professor of medicine at Harvard Medical School and Brigham and Women’s Hospital. I’d like to talk with you about a recent report from the Study of Women’s Health Across the Nation (SWAN) that was recently published in JAMA Internal Medicine. The report sheds light on the effect of menopausal hormone therapy on cardiovascular disease (CVD) risk among women with hot flashes and other vasomotor symptoms, and how that effect varies by the timing of hormone therapy initiation.Although this is an observational study that may have some confounding by socioeconomic status and health-related factors, it’s very rigorously done and was designed as a trial emulation study. This study has similar results to the Women’s Health Initiative (WHI) randomized trial among women with hot flashes. The SWAN study started nearly 30 years ago. It’s a longitudinal study of the menopause transition and post-menopause. Eligible participants in this analysis were women who reported hot flashes and/or night sweats over the past 2 weeks, were free of CVD at baseline, and had no prior hormone therapy use. The main outcomes were CVD events, including myocardial infarction, stroke, heart failure, revascularization, and CVD death. About 2700 women with hot flashes were included in the analysis, and 755 started menopausal hormone therapy at a mean age of 53 years. Participants were followed long term, during which 224 CVD events occurred.Overall, the adjusted hazard ratio of CVD events for hormone therapy initiation vs noninitiation was significantly reduced by 22%, and the hazard ratio varied by the age at initiation. It was 27% lower for those starting less than menopausal hormone therapy 10 years since onset of menopause and nonsignificantly elevated at 1.53 among the women who initiated menopausal hormone therapy more than 10 years from the onset of menopause.The P value for interaction by time since menopause was .02. So, these results suggest that starting hormone therapy early in menopause among women with hot flashes is associated with a modest 22% reduction in CVD risk, and the benefits were more pronounced in the women who initiated menopausal hormone therapy within 10 years of menopause onset.These results are very similar to those in the WHI among women with hot flashes. Those results were also recently published in JAMA Internal Medicine and similarly showed a trend toward a modest 15%-16% reduction in CVD among women with hot flashes who initiated hormone therapy at age 50-59 years vs an elevated risk among the women initiating at after age 70. An intermediate risk was found among those starting in their 60s. This similarity in the findings provides reassurance about the reliability of the results. Please note that these findings do not mean that hormone therapy should be started for the express purpose of preventing heart disease, because residual confounding is still possible in these analyses, but rather that the results are reassuring for the use of hormone therapy to treat hot flashes early in menopause, when women are more likely to have vasomotor symptoms and more likely to get quality-of-life benefits.Thus, on this topic, timing is everything and the use of hormone therapy early in menopause to treat hot flashes is a good clinical choice. Thank you so much for your attention. This is JoAnn Manson.