A re-analysis of the Women's Health Initiative has reversed the conclusions reported in 2002 that appeared to finally end the controversy about hormone replacement therapy in post-menopausal women; that conclusion was that HRT to prevent cardiovascular disease was not only useless but also potentially harmful.

As a result, millions of women stopped taking or declined to initiate HRT, preferring to deal with their menopausal symptoms as best they could.

That was then; this is now. A re-evaluation of the study published in the April 4, 2007, issue of the Journal of the American Medical Association has suggested the primary conclusions reported and widely accepted were overreaching and fundamentally incorrect.

The Women's Health Initiative examined 27,000 women aged 50 to 79. HRT (in doses and formulations appropriate for the time, and depending on whether or not they had hysterectomies) was assigned to half of the women. After several years and at a preliminary review of the available data, it was concluded that those on HRT were at a significantly increased risk of cardiovascular disease, stroke and breast cancer. This prompted the premature termination of the study and the wide publication of the results.

Of course, since women declined HRT as a result of the original flawed conclusions, it may be inferred that many women may have placed themselves, with the recommendations of their well-meaning healthcare providers, at subsequently increased risk of cardiovascular adverse events, as well as suffering uncomfortable menopausal symptom. This also may translate to an additional future risk of osteoporosis.

The culprit here is likely the analysis of the data. In the field of information technology, it is known that data are not useful until they have been converted into applied information.

The recent in-depth analysis took age into account. The researchers realized that if they looked at the women who started HRT immediately after menopause in effect, the youngest women in the study their overall cardiovascular risk was 24 percent lower than those not on HRT. If women waited until 20 years after menopause to begin HRT, their risk was 28 percent higher.

It may be that starting HRT with younger and healthier blood vessels protects them. Thus, increased cardiovascular risks seemed confined to only the oldest women in the study. Indeed, the younger women, in their 50s, seemed to have up to a 30 percent reduced risk of premature death from any cause, and there was no increased risk of stroke.

There still seems to be a slightly increased risk of breast cancer if HRT was a combination of estrogen and progesterone.

A conclusion from this re-evaluation is that hormone replacement therapy may again be a reasonably safe and potentially beneficial option for women under 60 suffering the symptoms of menopause. The long-term cardiovascular benefits remain a bit uncertain, and patients need to discuss them with their physicians.

Dr. Irving Loh is medical director of the Ventura Heart Institute in Thousand Oaks, http://www.venturaheart.com. His e-mail address is drloh@venturaheart.com.