Anti-ischemic effect of chronic oestrogen replacement therapy alone or in combination with medroxyprogesterone acetate in different replacement schemes

Background: Oestrogen replacement therapy in postmenopausal women has a pro tective effect upon the cardiovascular system and improves exercise-induced myocardial ischemia. Although in hormone replacement schemes progestins ar e required to reduce the likelihood of uterine malignancies, little is know n on the cardiovascular effect of progestins. The purpose of this study was to evaluate the effect of oestrogen replacement alone and two different es trogen-progestin replacement therapy schemes upon exercise induced myocardi al ischemia. Material and method: The study population included 18 female m enopausal patients with coronary artery disease. After a baseline exercise test patients received conjugated equine estrogens (CEE) 0.625 mg alone for 30 days when they underwent a second exercise test and were randomized to receive in a cross-over design medroxyprogesterone acetate (MPA) either in continuous combined therapy (2.5 mg/daily) for 28 days or in cyclical thera py (10 mg o.d. from day 16 to day 28). Results: After CEE alone two patient s with a previously positive exercise test showed a negative exercise test. CEE increased time to 1 mm ST compared to baseline (352 +/- 185 vs 265 +/- 133 s, P < 0.01). In the 2 pts in whom the exercise test was negative afte r CEE the test remained negative during continuous combined MPA therapy whi le become positive during cyclical MPA. CEE + continuous combined MPA incre ased both time to I min ST and exercise time compared to baseline (386 +/- 165 vs 265 +/- 133 s, P < 0.01 and 545 +/- 198 vs 465 +/- 186 s, P < 0.05 r espectively). No difference was found between baseline and CEE + cyclical N IPA in either time to 1 mm ST or exercise time (268 +/- 164 vs 265 +/- 133 s, P = NS and 455 +/- 223 vs 465 +/- 186 s, P = NS, respectively). Conclusi on: Continuous combined therapy with CEE + MPA improves exercise-induced my ocardial ischemia in female patients with coronary artery disease while the beneficial effect of CEE is reduced by cyclical therapy. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.