Hormone Replacement Therapy Is Associated with Less Coronary Atherosclerosis in Postmenopausal Women

Abstract

Most observational studies indicate that hormone replacement therapy (HRT) protects women from cardiovascular disease. Two recent randomized trials, however, showed no reduction in coronary events with HRT in postmenopausal women. A randomized study evaluating subclinical atherosclerosis showed a beneficial effect of estrogen. In the current study we evaluated the association between HRT and coronary artery atherosclerosis, as quantified by coronary artery calcium score. Current users of HRT were significantly more likely to have a coronary artery calcium score less than 100 and were less likely to have a score greater than 400 than non-HRT users. After adjustment for cardiac risk factors, current use of HRT was associated with a significant reduction of coronary artery calcium score (-28; 95% confidence interval, -48 to -10). The average age of users was 59 yr, the mean duration of use was 9 yr, and the duration of HRT use was significantly associated with a reduction in coronary artery calcium. These results suggest that HRT suppresses atherosclerosis in the coronary arteries. The failure to modify the cardiovascular event rate in clinical trials could result from the adverse effect of HRT on complicated lesions. Additional mechanistic studies may help identify therapeutic strategies that could maximize a potential benefit of HRT on early atherogenesis while minimizing adverse proinflammatory and procoagulant effects on complicated plaque lesions.

Vascular Calcification

“…Some clinical studies now confirm higher calcium content in coronary plaques of women using hormone replacement therapy (HRT), 104,105 whereas other observational studies report reduction in coronary calcification with HRT. 106 Conclusions about the relationship between estrogen and coronary calcification cannot be reliably determined from observational studies. Unfortunately, the only data available now regarding estrogen and CAC are observational.…”

Decreased Binding of Annexin V to Endothelial Cells

“…23 Apoptosis may also prevent atherosclerosis by reducing the cellular content and neointimal thickening of the plaque. However, increased apoptosis may render the plaques more vulnerable, especially at the shoulder region where the fibrous cap is thin.…”

The role of electron beam computed tomography for measuring coronary artery atherosclerosis

“…Conversely, studies in animals have shown that HRT can beneficially affect coronary artery atherosclerosis [38][39][40]. A recent large study of postmenopausal women has shown that HRT use is associated with less coronary atherosclerosis as measured by EBT [41]. This latter result suggests that a potential explanation for the conflicting animal and human data with HRT could be related to the proinflammatory and prothrombotic effect of such therapy on established vessel wall lesions, even with a potentially beneficial effect in suppressing lesion formation.…”