User age determines effects of HT on coronary artery disease.
The WHI clinical trials were designed in 1991 and 1992 primarily to determine whether oral menopausal HT protects against coronary artery disease (CAD), as a large body of literature based on observational studies had suggested. Most of those observational studies had involved unopposed oral estrogen. (1)
When the estrogen-progestin arm of the WHI was halted in 2002, investigators noted that use of conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA) overall was associated with a 29% increase in the risk of CAD (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.02-1.63) and a more than 200% increase in the risk of venous thromboembolism (HR, 2.11; 95% CI, 1.49-2.87), compared with placebo. Subsequent reports explored this connection from different angles (see the timeline on pages 56, 57).
In 2007, important--and, for some, startling--findings were published regarding HT and the risk of CAD, most notably:
* When estrogen users from both arms of the WHI trial were combined into one group, those who were less than 10 years since the onset of menopause had a HR for CAD of 0.76 (95% CI, 0.5-1.16), and oral HT was associated with six fewer cases of CAD for every 10,000 woman-years of use. Similar findings were reported for women 50 to 59 years old. Among older WHI participants and those more distant from menopause, HT was associated with an elevated risk of CAD.
* In the same cohort, mean coronary artery calcium scores overall were more favorable among women receiving estrogen than among those randomized to placebo (P=.02). Among women who took the study medication most consistently (at least 80% adherent), an even greater reduction in coronary artery calcification was noted with estrogen use, which was associated with a 61% reduction in the risk of having extensive coronary artery calcification (P=.004). The authors concluded: "... estrogen therapy may have cardioprotective effects in younger (menopausal) women."
In contrast to earlier WHI reports, which failed to break out risks by user age, these recent publications are consistent with the earlier observational studies of HT and should reassure ObGyns that the patients most likely to experience menopausal symptoms (women in their 50s and early 60s) can use HT without increasing their risk of CAD.
Rossouw JE, Prentice PL, Manson JE, et al. Postmenopausal hormone therapy and risk of cardiovascular disease by age and years since menopause. JAMA. 2007;297:1465-1477.
Manson JE, Allison MA, Rossouw JE, et al. Estrogen therapy and coronary-artery calcification. N Engl J Med. 2007;356:2591-2602.
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|Title Annotation:||UPDATE: HOW DEVELOPMENTS ARE CHANGING PATIENT CARE; hormone therapy|
|Author:||Kaunitz, Andrew M.|
|Date:||May 1, 2008|
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