Authors' objectives:

Cardiovascular disease (CVD) is the leading cause of death among women in the United States (US), and hormone replacement therapy (HRT) is commonly used, often for the prevention of CVD. The goal of this systematic evidence review and meta-analysis is to evaluate the association between HRT and the primary prevention of CVD, including total CVD, coronary artery disease (CAD), and stroke, when they were evaluated as separate subsets.

Authors' results and conclusions: The summary relative risk for CVD mortality with any HRT use was 0.75 (95% CI, 0.42-1.23) and for current users was 0.64 (95% CI, 0.44-0.93). CAD mortality was associated with a relative risk of 0.74 (95% CI, 0.36-1.45) for any use and 0.62 (95% CI, 0.40-0.91) for current use. No significant association between HRT and risk of stroke death was identified. In contrast to the mortality findings, the summary relative risk for CVD incidence is 1.28 (95% CI, 0.86-2.00) for any use and 1.27 (95% CI, 0.80-2.00) for current use. Stroke incidence was significantly increased among women using HRT, with a summary relative risk of 1.12 (95% CI 1.01-1.23), largely due to a significant increase in atherothrombotic stroke among women using HRT. In our meta-analysis, the pooled relative risk of CAD associated with any use of HRT was 0.87 (95% CI, 0.62-1.21) and for current use was 0.80 (95% CI, 0.68-0.95). When studies adjust for socioeconomic status (SES) as well as other major CAD risk factors, the summary relative risk of CAD is 0.97 (95% CI, 0.82-1.16) among current users and 1.04 (95% CI, 0.79-1.44) among ever users. Similar results were found when the analysis stratified by studies adjusting for alcohol consumption and/or exercise, in addition to other major risk factors.

Authors' recommendations: The association between HRT and CVD incidence and mortality, as well as CAD and stroke incidence and mortality, is uncertain, based on conflicting findings, and limited by lack of randomization and consequent selection biases among women using HRT in the observational studies. Our meta-analysis differs from prior meta-analyses by evaluating potential explanatory variables of the HRT-CVD/CAD relationship, as well as different measures of HRT exposure. It shows a small decrease in CVD and CAD deaths only among current HRT users and no effect on stroke, and suggests that SES, alcohol use, and exercise are important confounders of the HRT/CVD/CAD relationship. A valid answer to the potential role of HRT in the primary prevention of CVD will best come from randomized controlled trials.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/uspstf/uspspmho.htm

Year Published: 2002

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)