Lr. Peterson et al., Short-term oral estrogen replacement therapy does not augment endothelium-independent myocardial perfusion in postmenopausal women, AM HEART J, 142(4), 2001, pp. 641-647
Citations number
33
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Objectives Th. purpose of this study was to determine the effect of usual-d
ose estrogen replacement therapy (ERT) on myocardial perfusion and myocardi
al perfusion reserve (MPR) (evoked by an endothelium-independent vasodilato
r) in healthy postmenopausal women. Postmenopausal women have a decreased m
yocardial perfusion reserve compared with younger women. Estrogen infusions
are known to enhance endothelium-dependent vasodilation of the epicardial
coronary arteries in postmenopausal women, but whether ERT also enhances en
dothelium-independent myocardial perfusion and perfusion reserve is unclear
.
Methods In 2.4 healthy postmenopausal women who were not taking ERT, myocar
dial perfusion at rest, perfusion during the infusion of adenosine (a prima
rily endothelium-independent vasodilator), and MPR were determined by posit
ron-emission tomography (PET) and oxygen 15-labeled water. The women were t
hen randomly assigned in a double-blind fashion to receive either 0.625 mg
of oral conjugated estrogens (Premarin) or placebo per day for 4 to 6 weeks
, after which they underwent a repeat cardiac PET study.
Results There was no statistical difference between those assigned to ERT a
nd those assigned to placebo in the measurement of myocardial perfusion at
rest (1.21 +/- 0.31 vs 1.16 +/- 0.18 mL/g/min, respectively) in response to
adenosine (2.66 +/- 0.96 vs 3.3 +/- 0.45 mL/g/min) or MPR (2.24 +/- 0.83 v
s 2.88 +/- 0.64 mL/g/min) after 4 to 6 weeks of oral ERT. There was also no
difference between the groups in any of the myocardial perfusion measureme
nts after correction for the rate-pressure product.
Conclusions Short-term oral ERT does not affect myocardial perfusion at res
t in response to adenosine or MPR in healthy postmenopausal women. Thus pot
ential beneficial effects of ERT on vasomotor function may be limited to en
hancement of endothelium-dependent vasodilative mechanisms affecting condui
t vessels.