Hormone replacement therapy and cardiovascular disease revisited.

Controversy still rages about whether hormone replacement therapy (HRT) confers cardiovascular benefit or harm. There is a wealth of biological evidence that estrogen has a beneficial effect, supporting a large body of epidemiological evidence demonstrating reduction in coronary events with HRT. A large randomized placebo-controlled clinical trial of preventive strategies for coronary heart disease (CHD) in postmenopausal women, the Women's Health Initiative (WHI), included HRT arms. The published preliminary findings of this trial showed a significant increase in coronary events, stroke, venous thromboembolism and breast cancer with estrogen-progestogen, leading to the conclusion that HRT was unsafe to use other than for short-term relief of menopausal symptoms. But subsequent publications of the more complete data from WHI have shown no significant increase in CHD, and a tendency to a reduction in those initiating HRT below age 60 years. This is important because other therapeutic strategies for the primary prevention of CHD, such as aspirin and statins, are not of proven benefit in women, in contrast to men. Subsequent WHI findings have not shown a clear increase in breast cancer, and any potential increase from HRT is similar to that seen with many lifestyle factors and other commonly used medications. The preliminary WHI results do not reflect accurately true benefits and risks, and HRT should remain a potential preventive treatment for CHD.