Dr. Marcia Stefanick, WHI Steering Committee Chair from Stanford University, summarized the cardiovascular studies that led to the WHI trials. These included the Postmenopausal Estrogen/Progestin Interventions (PEPI) trial, which compared the effects of E alone, and E plus many progestin regimens, on CHD risk factors (
The Writing Group for the PEPI Trial. Effects of estrogen or estrogen/progestin regimens on heart disease risk factors in postmenopausal women. JAMA. 1995; 273:199-208.
). Although the results were positive, this trial could not directly test whether CHD would be prevented. The Heart and Estrogen/progestin Replacement Study (HERS) was a secondary prevention trial of E + P that showed no benefit for CHD; in fact, there were indications of early harm (
Hulley S, Grady D, Bush T, Furberg C, Herrington D, Riggs B. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. JAMA. 1998; 280:605-13.
). Other WHI investigators presented the results from the E + P study (summarized in the Table) (
Rossouw JE, Anderson GL, Prentice RL, LaCroix AZ, Kooperberg C, Stefanick ML. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial. JAMA. 2002; 288:321-33.
), stressing that the JAMA report does not provide the nuances that will be developed through subgroup analyses; WHI investigators plan to publish detailed analyses of the effects of E + P on the development of cardiovascular disease, cancer, osteoporosis, cholelithiasis, degenerative arthritis, sexual function, cognition and dementia, and quality of life. They will also analyze the effect of previous hormone use on the risk for breast cancer. All these analyses will use the complete, centrally adjudicated clinical outcomes and will include laboratory studies of risk markers.