Does sublingual 17{beta}-oestradiol have any effects on exercise capacity and myocardial ischaemia in post-menopausal women with stable coronary artery disease?

Background A variety of vascular effects have been ascribed to 17ß-oestradiol.These effects may partially explain the reduced incidence ofcardiovascular disease found in post-menopausal women on oestrogenreplacement therapy. Objectives To evaluate the effects of 2mg sublingual 17ß-oestradiolon exercise capacity, exercise-induced myocardial ischaemiaand circulating levels of endothelin-1 in post-menopausal womenwith stable coronary artery disease. Methods Twelve post-menopausal women, mean age 61 (range 52–72)years, with angiographically verified significant coronary arterydisease, were randomly assigned to 2mg of sublingual 17ß-oestradiol,2·5mg of buccal nitroglycerine and to placebo in a double-blindcross-over study design with at least 2 days between each ofthe study arms. Antianginal medications, with the exceptionof beta-blockers, were discontinued before investigation. Allstudy patients underwent a maximal bicycle exercise test 30minafter drug intake. Blood was withdrawn immediately before andup to 8h after medication for analyses of circulating levelsof oestradiol and endothelin-1. Results The mean serum levels of oestradiol increased from a controllevel of 72±28pmol.l^–1to 3557± 1631pmol.l^–1after30min and to 5028±3971pmol.l^–1after 60min witha gradual decline thereafter. Sublingual 17ß-oestradioldid not induce any improvement in exercise duration when comparedwith nitroglycerin and placebo (500±112s, 505±107s,498±157s), and did not influence time to onset of ST-segmentdepression (358±89s, 436±93s, 384±116s).The plasma levels of endothelin-1 did not change after administrationof 17ß-oestradiol, nitroglycerin or placebo. Conclusions No effects on exercise capacity, exercise-induced acute ischaemia,or plasma levels of endothelin-1 were found after a single doseof 2mg 17ß-oestradiol in post-menopausal women withdocumented coronary artery disease.