Effect of estrogen plus progestin on progression of carotid atherosclerosis in postmenopausal women with heart disease: HERS B-mode substudy.

Objective: The Heart and Estrogen/Progestin Replacement Study (HERS) found no overall effect of estrogen plus progestin (compared with placebo) on coronary event rates in 2763 postmenopausal women with established coronary disease (mean 4.1 years of follow-up). In addition to the events trial, a carotid ultrasound substudy was established in 1993 to be conducted concurrently to determine whether hormone therapy affects the progression of the underlying atherosclerotic process.

Methods And Results: Within the larger HERS, a subset of 362 participants underwent carotid B-mode ultrasound examinations at baseline and the end of follow-up. Progression of carotid atherosclerosis was measured as the temporal change in intimal-medial thickness (IMT).

Conclusions: IMT progressed in the hormone treatment and placebo groups, although there was no statistical difference between the rates: IMT progressed 26 microm/y (95% CI 18 to 34 microm/y) in the hormone group and 31 microm/y (95% CI 21 to 40 microm/y) in the placebo group (P=0.44). There were also no significant treatment effects when the results were examined by carotid segment or were adjusted for covariates. These data support the American Heart Association recommendation that women with established coronary disease should not initiate hormone therapy with an expectation of atherosclerotic benefit.