Estrogen Therapy and Coronary-Artery Calcification

To the Editor: In their article on the Women's Health Initiative Coronary-Artery Calcium Study (WHI-CACS), Manson et al. (June 21 issue) 1 provide insight into another mechanism by which estrogen therapy reduces coronary heart disease (CHD) in women who have undergone hysterectomy and who initiate such therapy close to menopause. 2 The authors' findings further support the hypothesis that early initiation of such therapy has a beneficial effect. 3 For women under the age of 60 years, scientific evidence indicates that estrogen therapy is as efficacious in reducing CHD as are other primary prevention therapies, such as lipid-lowering drugs and aspirin, and is . . .