A new analysis from the WHI observational study addresses the potential differences in risk for cardiovascular disease (CVD) associated with different doses, formulations and routes of administration of postmenopausal hormone therapy (HT) [1)]. As a reminder, the WHI observational trial was a multicenter, prospective cohort study that was conducted at 40 US sites. Analyses included 93,676 postmenopausal women aged 50–79 years at study entry, with a mean follow-up of 10.4 years. In direct comparisons, oral estradiol was associated with lower hazard ratios (HRs) for stroke than oral conjugated equine estrogens (CEE; HR 0.64; 95% CI 0.40–1.02), but statistical power was limited. Similarly, transdermal estradiol was associated with a moderate but non-significantly lower risk of coronary heart disease (CHD) compared with oral CEE (HR 0.63; 95% CI 0.37–1.06). For other outcomes, comparisons revealed no appreciable differences by estrogen doses, formulations, or routes of delivery. Absolute risks of CVD events and all-cause mortality were markedly lower in younger women compared with older women.
Department of Medicine T, Ichilov Hospital, Tel-Aviv, Israel
Shufelt CL, Merz CN, Prentice RL, et al. Hormone therapy dose, formulation, route of delivery, and risk of cardiovascular events in women: findings from the Womens Health Initiative Observational Study. Menopause 2013 Sep 16. Epub ahead of print