Board index » cardiology » Estrogen Therapy and Coronary-Artery Calcification

2007-06-21 08:47:38 PM
Estrogen Therapy and Coronary-Artery Calcification
NEJM, Volume 356:2591-2602
Background Calcified plaque in the coronary arteries is a marker for
atheromatous-plaque burden and is predictive of future risk of
cardiovascular events. We examined the relationship between estrogen
therapy and coronary-artery calcium in the context of a randomized
clinical trial.
Methods In our ancillary substudy of the Women's Health Initiative
trial of conjugated equine estrogens (0.625 mg per day) as compared
with placebo in women who had undergone hysterectomy, we performed
computed tomography of the heart in 1064 women aged 50 to 59 years at
randomization. Imaging was conducted at 28 of 40 centers after a mean
of 7.4 years of treatment and 1.3 years after the trial was completed
(8.7 years after randomization). Coronary-artery calcium (or Agatston)
scores were measured at a central reading center without knowledge of
randomization status.
Results The mean coronary-artery calcium score after trial completion
was lower among women receiving estrogen (83.1) than among those
receiving placebo (123.1) (P=0.02 by rank test). After adjustment for
coronary risk factors, the multivariate odds ratios for coronary-
artery calcium scores of more than 0, 10 or more, and 100 or more in
the group receiving estrogen as compared with placebo were 0.78 (95%
confidence interval, 0.58 to 1.04), 0.74 (0.55 to 0.99), and 0.69
(0.48 to 0.98), respectively. The corresponding odds ratios among
women with at least 80% adherence to the study estrogen or placebo
were 0.64 (P=0.01), 0.55 (P<0.001), and 0.46 (P=0.001). For coronary-
artery calcium scores of more than 300 (vs. <10), the multivariate
odds ratio was 0.58 (P=0.03) in an intention-to-treat analysis and
0.39 (P=0.004) among women with at least 80% adherence.
Conclusions Among women 50 to 59 years old at enrollment, the
calcified-plaque burden in the coronary arteries after trial
completion was lower in women assigned to estrogen than in those
assigned to placebo. However, estrogen has complex biologic effects
and may influence the risk of cardiovascular events and other outcomes
through multiple pathways. (ClinicalTrials.gov number, NCT00000611
[ClinicalTrials.gov] .)
* * *
I personally don't find this study very persuasive, but I guess
reasonable people could differ on this. If a woman has had a
hysterectomy and wants to take estrogen for a few years for menopausal
symptoms, I suppose she might find this study somewhat reassuring.
Marilyn
-

The New York Times article on this is at
www.nytimes.com/2007/06/21/health/21estrogen.html
-