Transdermal hormone replacement therapy (HRT) does not reduce the risk of cardiac events in postmenopausal women with existing coronary artery
Transdermal hormone replacement therapy (HRT) does not reduce
the risk of cardiac events in postmenopausal women with existing
coronary artery disease (CAD). In the PHASE trial (Papworth HRT
Atherosclerosis Study), researchers randomized 255
postmenopausal women with angiographically proven coronary
artery disease to receive either transdermal HRT--17-beta-estradiol
with or without cyclic norethisterone--or no hormone replacement therapy. The women were followed for 4 years. Overall, 134 women received hormone replacement therapy. Of these, 58 had a previous hysterectomy. The other 121 women served as controls.
On intention-to-treat analysis, there was no statistical difference in the incidence of unstable angina requiring hospitalization, MI or
premature death from heart disease in women receiving HRT and
women not receiving the therapy. Respectively, the average event
rates were 15.6 and 12.6 per 100 patient-years. Results from the
PHASE study also seem to indicate an increased risk of
thromboembolic complications, such as stroke, with HRT. This
observation is supported by results from the HERS study, a
randomized trial carried out in the US that included 3000 women,
and was designed to assess the cardioprotective effect of
combined HRT in women with documented CAD. It may therefore
be appropriate that women with proven coronary artery disease
should not commence HRT. Nevertheless, women receiving HRT
for more than 2 years should continue.
