OBJECTIVES: To measure the effects of combined cyclical hormone replacement therapy (HRT) on myocardial blood flow (MBF) in postmenopausal women at high risk for coronary heart disease (CHD) and in women with documented CHD. BACKGROUND: Estrogen restores endothelium-dependent vasodilation in response to acetylcholine in postmenopausal women, and it has a direct, endothelium-independent vasodilatory effect on coronary arteries. METHODS: To determine whether coronary microcirculation can be affected by short-term, combined HRT, we performed positron emission tomography (PET) in two groups of women without previous HRT. Group I (n = 10) had one or more risk factors for CHD; group II (n = 8) had documented CHD and previous myocardial infarction. Group II was older (54 +/- 4 vs 59 +/- 5 y, P = .03) and had lower total cholesterol levels at baseline because of lipid-lowering therapy (244 +/- 31 vs 203 +/- 40 mg/dL, P = .03). Patients underwent baseline dynamic PET with N-13 ammonia at rest and during maximal adenosine-induced hyperemia to assess MBF. Each then began taking HRT (conjugated equine estrogen alone or with medroxyprogesterone acetate (MPA), administered in cyclical fashion), and returned for follow-up PET 46 +/- 12 days later. RESULTS: There was no difference in resting MBF between groups I and II prior to starting therapy or at follow-up. Stress MBF and flow reserve (FR) tended to be higher in group I patients at baseline. MBF values remained unchanged at follow-up and resulted in similar FR values at baseline and during HRT for both groups. Women using only estrogen (n = 6) tended to show higher FR values after estrogen therapy, however. CONCLUSIONS: Short-term HRT in postmenopausal women did not lead to improvements in MBF or FR. Combined cyclical HRT may not exert measurable effects on coronary microcirculation. MPA may attenuate estrogen effects on the coronaries, which may be largely endothelium-dependent.
OBJECTIVES: To measure the effects of combined cyclical hormone replacement therapy (HRT) on myocardial blood flow (MBF) in postmenopausal women at high risk for coronary heart disease (CHD) and in women with documented CHD. BACKGROUND: Estrogen restores endothelium-dependent vasodilation in response to acetylcholine in postmenopausal women, and it has a direct, endothelium-independent vasodilatory effect on coronary arteries. METHODS: To determine whether coronary microcirculation can be affected by short-term, combined HRT, we performed positron emission tomography (PET) in two groups of women without previous HRT. Group I (n = 10) had one or more risk factors for CHD; group II (n = 8) had documented CHD and previous myocardial infarction. Group II was older (54 +/- 4 vs 59 +/- 5 y, P = .03) and had lower total cholesterol levels at baseline because of lipid-lowering therapy (244 +/- 31 vs 203 +/- 40 mg/dL, P = .03). Patients underwent baseline dynamic PET with N-13 ammonia at rest and during maximal adenosine-induced hyperemia to assess MBF. Each then began taking HRT (conjugated equine estrogen alone or with medroxyprogesterone acetate (MPA), administered in cyclical fashion), and returned for follow-up PET 46 +/- 12 days later. RESULTS: There was no difference in resting MBF between groups I and II prior to starting therapy or at follow-up. Stress MBF and flow reserve (FR) tended to be higher in group I patients at baseline. MBF values remained unchanged at follow-up and resulted in similar FR values at baseline and during HRT for both groups. Women using only estrogen (n = 6) tended to show higher FR values after estrogen therapy, however. CONCLUSIONS: Short-term HRT in postmenopausal women did not lead to improvements in MBF or FR. Combined cyclical HRT may not exert measurable effects on coronary microcirculation. MPA may attenuate estrogen effects on the coronaries, which may be largely endothelium-dependent.
Authors: Thomas H Schindler; Xiao-Li Zhang; Gabriella Vincenti; Leila Mhiri; René Lerch; Heinrich R Schelbert Journal: J Nucl Cardiol Date: 2007-07 Impact factor: 5.952
Authors: Thomas H Schindler; Roxana Campisi; Deborah Dorsey; John O Prior; Manfred Olschewski; James Sayre; Heinrich R Schelbert Journal: Eur Heart J Date: 2009-02-26 Impact factor: 29.983
Authors: Venkatesh L Murthy; Timothy M Bateman; Rob S Beanlands; Daniel S Berman; Salvador Borges-Neto; Panithaya Chareonthaitawee; Manuel D Cerqueira; Robert A deKemp; E Gordon DePuey; Vasken Dilsizian; Sharmila Dorbala; Edward P Ficaro; Ernest V Garcia; Henry Gewirtz; Gary V Heller; Howard C Lewin; Saurabh Malhotra; April Mann; Terrence D Ruddy; Thomas H Schindler; Ronald G Schwartz; Piotr J Slomka; Prem Soman; Marcelo F Di Carli; Andrew Einstein; Raymond Russell; James R Corbett Journal: J Nucl Cardiol Date: 2018-02 Impact factor: 5.952