0

The full content of Annals is available to subscribers

Subscribe/Learn More  >
Ideas and Opinions |

The HERS Trial Results: Paradigms Lost?

David M. Herrington, MD, MHS
[+] Article and Author Information

From Wake Forest University School of Medicine, Winston-Salem, North Carolina.


Disclosure: Dr. Herrington is a member of the HERS Executive Committee and has received research support from Wyeth-Ayerst Research, sponsor of the HERS trial.

Requests for Reprints: David M. Herrington, MD, MHS, Department of Internal Medicine/Cardiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045; e-mail, dherring@wfubmc.edu.


Ann Intern Med. 1999;131(6):463-466. doi:10.7326/0003-4819-131-6-199909210-00012
Text Size: A A A

The Heart and Estrogen/progestin Replacement Study (HERS) found no overall effect of 4.1 years of therapy with estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. However, within the overall null effect, a 50% increase in cardiovascular events was seen in the first year, followed by fewer events after 2 years of treatment in the hormone therapy group than in the placebo group. Understanding the cause of this pattern of early increase and late reduction in risk is key to interpreting the HERS results and reconciling them with the large number of observational and other studies of the cardiovascular effects of estrogen. There are two possibilities. One is that the HERS regimen of estrogen plus progestin has no effect on risk for heart disease, and the pattern of changing risk over time is simply the result of chance or confounding. The other is that the pattern of early increase and late reduction in risk is due to real but opposing effects of this regimen. Several lines of evidence support each possibility. Attrition of a susceptible cohort of women uniquely at risk for a cardiovascular complication from hormone therapy coupled with a gradually progressive beneficial effect due to lipid lowering and other factors is a promising potential explanation. The HERS results remind us of the need for clinical trials to evaluate both the benefits and risks of new therapies. They also illustrate how much more we need to know about the cardiovascular effects of hormone replacement therapy.

Figures

Grahic Jump Location
Figure.
Model of the possible impact of attrition of women with a susceptibility factor on the pattern of relative risk for myocardial infarction and death from coronary heart disease among women assigned to estrogen plus progestin or placebo over time in the Heart and Estrogen/progestin Study cohort. Left.Right.

White bars represent a projected pattern of relative risk, assuming attrition of a susceptible cohort and no beneficial effects of hormone replacement therapy. Striped bars represent a projected pattern of relative risk, assuming a monotonic reduction in risk beginning in year 2 and no harmful effects of the intervention in year 1. Results when these effects are combined.

Grahic Jump Location

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Advertisement
Related Articles
Topic Collections
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)