Anna Liachenko, BSc, MSc
A large body of observational evidence suggested that estrogen replacement therapy (ERT) after menopause decreases a women's lifetime risk of death from myocardial infarction by 35 to 50 percent and increases life expectancy by 2 to 3 years. However, a recent major clinical trial concluded that estrogen plus progestin therapy did not decrease the overall risk of myocardial infarction and coronary death among postmenopausal women with previous heart disease. The main question raised by the results of the trial is whether doctors should change their prescribing patterns and which patient populations will be affected. While there is no simple answer, it is important to consider the issues involved such as, How serious were the limitations of the observational research? Did the trial look at the right group of patients? How far can we extrapolate the results? And what are the future implications?
The Heart and Estrogen/progestin Replacement Study (HERS) trial was a randomized, blinded, placebo-controlled trial designed to test the efficacy and safety of hormone replacement therapy (HRT, estrogen plus progestin) on secondary prevention of heart disease. The trial involved 2763 postmenopausal women with established coronary artery disease. In the HRT group, the rate of coronary events increased by 50% in the first year of the trial and subsequently decreased by 40% in the forth and fifth years, yielding no significant effect overall.