Several studies had previously demonstrated a protective effect of hormone therapy (HT) in reducing risk of CHD. However, data from two large prospective trials, the Women’s Health Initiative (WHI) and the Heart and Estrogen/progestin Replacement Study (HERS), seemed to indicate that hormone therapy did not result in risk reduction in CHD. An increase in CHD events was observed in the treatment group compared to placebo in both studies. An increased risk of stroke was also observed in the WHI study. Subsequent follow-up of patients, a modest decrease in CHD was observed, attributed to the cumulative effect of long-term usage of estrogen alone. Analysis of data for CHD risk factors showed superior lipid, insulin and glucose profiles with HT compared to placebo. Strict adherence to the study medication regimen resulted in a significant decrease in coronary artery calcification. There is some evidence indicating that the benefits of HT may be observed when it is used close to menopause.