TORONTO, CANADA. Conventional medical wisdom has it that hormone replacement therapy reduces the risk of cardiovascular disease in postmenopausal women. However, a recent large-scale clinical trial, the Heart and Estrogen/Progestin Replacement Study (HERS), involving 2763 women concluded that hormone replacement therapy (HRT) is of no benefit. Now Dr. John Blakely, MD of the Sunnybrook and Women's College Health Sciences Centre suggests that not only does HRT not reduce cardiovascular risk, but it actually increases it. Dr. Blakely points out that HERS found that women on HRT had 50 per cent more cardiac events (an absolute increase of 1.4 per cent) during the first year of treatment than did women not on HRT. In later years the surviving women on HRT tended to have fewer events, but Dr. Blakely estimates that it would take at least 10 years before HRT-treated women gained just one month of event-free survival as compared to non-treated women. He concludes that the treated group experienced "net harm" with fewer patient-months of event-free survival in those taking HRT. He goes on to say that women with or at high risk of coronary heart disease should not start HRT and there is a risk that women without heart disease might experience even greater net harm from HRT.
Blakely, John A. The Heart and Estrogen/Progestin Replacement Study revisited. Archives of Internal Medicine, Vol. 160, October 23, 2000, pp. 2897-2900