Acute effect of oestrogen replacement therapy on treadmill performance in postmenopausal women with coronary artery disease

Cardiovascular risk in women with non-specific chest pain (from the Women's Health Initiative Hormone Trials)

Women discharged with diagnoses of nonspecific chest pain (NSCP) may be at increased risk for subsequent coronary artery disease (CAD) events. The influence of hormone therapy on NSCP is unknown. The Women's Health Initiative (WHI) enrolled postmenopausal women aged 50 to 79 years. The duration of follow-up was 7.1 years in the WHI Estrogen-Alone trial (E-Alone) and 5.6 years in the WHI Estrogen Plus Progestin trial (E+P). After excluding women with previous cardiovascular disease, 9,427 women in E-Alone and 15,105 women in E+P were included in this analysis. NSCP, defined as having a primary hospital discharge diagnosis of NSCP by International Classification of Diseases, Ninth Revision, code, was reported in 322 women in E-Alone and 249 in E+P. Risks for subsequent CAD events were estimated using intent-to-treat Cox proportional-hazards models stratified by clinic and adjusted for age and other risk factors. In the fully adjusted models of the combined trials, women with NSCP had a twofold greater risk for subsequent nonfatal CAD events, including nonfatal myocardial infarction (2.3% vs 1.7%, hazard ratio [HR] 2.10, 95% confidence interval [CI] 1.11 to 3.98), revascularization (3.5% vs 2.6%, HR 1.99, 95% CI 1.20 to 3.30), and hospitalized angina (3.7% vs 2.3%, HR 2.39, 95% CI 1.46 to 3.92). Hormone therapy did not appear to have a significant effect on either the incidence of NSCP hospitalizations (E-Alone: HR 1.04, 95% CI 0.81 to 1.32; E+P: HR 0.78, 95% CI 0.59 to 1.02) or the risk for a subsequent CAD event. In conclusion, a hospitalization for NSCP doubles the risk for a subsequent CAD event in postmenopausal women over the next 5 to 7 years and identifies them as candidates for aggressive risk factor treatment.

Mechanism of ST segment depression during exercise tests in patients with liver cirrhosis

PURPOSE

To our experience, ST segment depression is sometimes detected in an exercise electrocardiogram (ECG) test in patients with liver cirrhosis who have no significant coronary stenosis. In this study, the mechanism of ST segment depression in liver cirrhosis was examined using (99m)Tc-methoxy-isobutyl-isonitrile (MIBI) myocardial scintigraphy.

METHODS

Six patients with liver cirrhosis (LC group), and 15 normal subjects (N group) were examined. To evaluate the level of myocardial blood flow, a Bull's eye display of myocardial blood flow was performed after dividing the left ventricle into 9 segments. Exercise myocardial scintigraphy with MIBI was performed to obtain the increase in % uptake. Angiographies were performed with a CAG system by inserting a 5 French Judkins catheter via the right femoral artery.

RESULTS

No significant coronary stenosis was found in any of the LC patients. Neither a decrease in MIBI uptake nor defect was observed on Bull's eye images from the LC group. The mean % uptake increase was 61.0 +/- 5.6% in the N group. In the LC group, although neither a decrease in MIBI uptake nor a defect was visually observed on Bull's eye images obtained during exercise, the % uptake increases (mean: 52.5 +/- 5.8%) were lower than those of the N group (p<0.05).

CONCLUSION

These findings suggest that a disorder in coronary flow reserve occurs in liver cirrhosis patients, because the decreased MIBI uptake during exercise is due to the depression of flow-mediated vasodilatation controlled by the endothelium of the coronary artery and the estrogenic digitalis action of blood flow independency.

Short-term oral estrogen replacement therapy does not augment endothelium-independent myocardial perfusion in postmenopausal women

OBJECTIVES

The purpose of this study was to determine the effect of usual-dose estrogen replacement therapy (ERT) on myocardial perfusion and myocardial perfusion reserve (MPR) (evoked by an endothelium-independent vasodilator) in healthy postmenopausal women. Postmenopausal women have a decreased myocardial 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 endothelium-independent myocardial perfusion and perfusion reserve is unclear.

METHODS

In 24 healthy postmenopausal women who were not taking ERT, myocardial perfusion at rest, perfusion during the infusion of adenosine (a primarily endothelium-independent vasodilator), and MPR were determined by positron-emission tomography (PET) and oxygen 15-labeled water. The women were then 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 and 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 vs 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 measurements after correction for the rate-pressure product.

CONCLUSIONS

Short-term oral ERT does not affect myocardial perfusion at rest in response to adenosine or MPR in healthy postmenopausal women. Thus potential beneficial effects of ERT on vasomotor function may be limited to enhancement of endothelium-dependent vasodilative mechanisms affecting conduit vessels.

Anti-ischemic action of estrogen-progestogen continuous combined hormone replacement therapy in postmenopausal women with established angina pectoris: a randomized, placebo-controlled, double-blind, parallel-group trial

The benefit of treating postmenopausal women with established cardiovascular disease with combined estrogen-progestogen hormone replacement therapy (HRT) is controversial. This study investigated the effect of treatment with estradiol and norethisterone acetate on exercise tolerance and on the frequency and severity of ischemic attacks in postmenopausal women with stable angina pectoris. A total of 74 Chinese women were recruited for this 16-week double-blind, placebo-controlled trial. They were randomly allocated into two groups; one group received placebo/placebo/placebo and the other group received placebo/estrogen-progestogen/placebo. Estrogen-progestogen continuous combined HRT increased both time to 1-mm ST depression (99.1 s, p < 0.05) compared with a mean decrease of 22.9 s with placebo (p < 0.05), and total exercise duration also showed a significant increase (32.7 s, p < 0.05) after treatment compared with placebo (2.5 s, p < 0.05). In addition, the total number of ischemic events/24 h during ambulatory electrocardiographic monitoring decreased by 0.82 events after treatment (p < 0.05) compared with an increase in the placebo group (0.94), a highly significant difference (p = 0.006). These results suggest that the administration of this particular combined hormone replacement preparation may have a beneficial effect on myocardial ischemia in postmenopausal women with established coronary disease.

Do we need clinical trials to test the ability of transdermal HRT to prevent coronary heart disease?

Postmenopausal hormone replacement therapy (HRT) with oral oestrogen was predicted to reduce coronary heart disease (CHD) risk by 50%. Randomized controlled trials show no such benefit, however, pointing instead to an initial increase in CHD events. Although the cardiovascular effects of transdermal HRT are largely unknown, improvements in arterial function are maintained when oestrogen is administered transdermally. Transdermal HRT also avoids the increased plasma levels of C-reactive protein (CRP) that are seen with oral HRT. However, the clinical significance of this general reduction in hepatic over-synthesis of plasma proteins is difficult to assess. Nevertheless, the available evidence on transdermal HRT appears to justify a formal clinical trial.

Does angina vary with the menstrual cycle in women with premenopausal coronary artery disease?

OBJECTIVE

To determine whether angina in women with established coronary heart disease varies with changes in hormone concentrations during the menstrual cycle.

DESIGN

Subjects were prospectively studied once a week for four weeks.

SETTING

Cardiology outpatient department of tertiary referral centre.

SUBJECTS

Nine premenopausal women, mean (SEM) age 38.89 (2.18) years, with established coronary heart disease, symptomatic angina, and a positive exercise test.

MAIN OUTCOME MEASURE

Myocardial ischaemia as determined by time to 1 mm ST depression during symptom limited exercise testing. Position in the menstrual cycle was established from hormone concentrations.

RESULTS

The early follicular phase, when oestradiol and progesterone concentrations were both low, was associated with the worst exercise performance in terms of time to onset of myocardial ischaemia, at 290 (79) seconds; the best performance (418 (71) seconds) was when oestrogen concentrations were highest in the mid-cycle (p < 0.05). Similar trends were observed in other measured variables. Progesterone concentrations did not influence exercise performance.

CONCLUSIONS

During the menstrual cycle myocardial ischaemia was more easily induced when oestrogen concentrations were low. This may be important for timing the assessment and evaluating treatment in women with coronary heart disease.

Long-term estrogen replacement therapy is associated with improved exercise capacity in postmenopausal women without known coronary artery disease

BACKGROUND

Short-term estrogen administration improves vasodilation and has been shown to improve exercise capacity. However, it is unknown whether long-term estrogen replacement therapy is associated with improved exercise capacity in postmenopausal women without known coronary artery disease.

METHODS AND RESULTS

We studied 248 postmenopausal women without known coronary artery disease (mean age 63.5 years); 158 (64%) were current or past hormone replacement therapy (HRT) users and 108 (44%) were current users of HRT. Attributes potentially affecting exercise capacity and cardiac risk factors were carefully measured. These included duration of estrogen replacement therapy, all variables in the Framingham risk index, physical activity level, body mass index, waist-to-hip ratio, presence of osteoporosis, and family history of heart disease. We measured maximal oxygen uptake (MVO (2)) and anaerobic threshold as objective markers of exercise capacity. The relation between exercise capacity and use of HRT was analyzed with the use of logistic regression, controlling for confounding variables. We found that fitness, as measured by MVO (2) and anaerobic threshold, was significantly greater in women who had used HRT currently or in the past compared with women who had never used HRT. This difference in fitness was not confounded by age or physical activity level.

CONCLUSIONS

Estrogen replacement therapy is associated with increased exercise capacity as measured by MVO (2) and anaerobic threshold in postmenopausal women without coronary artery disease. This finding is consistent with the beneficial effect of short-term estrogen administration on improved endothelium-dependent and endothelium-independent vasodilation.

Progestins in the menopause

While the benefits of progestin use in hormone replacement therapy (HRT) are well recognised as far as endometrial protection is concerned, their risks and drawbacks have generated controversial articles. The data related to the progestin effect on breast tissue has been interpreted differently from country to country. However it has been admitted that, according to the type of progestin used, the dose and duration of its application, a predominant antiproliferative effect is observed in the human breast cells. As far as breast cancer risk is concerned, most epidemiological studies do not suggest any difference between the estrogens given alone or combined to progestins in HRT. When the cardiovascular risk factors are considered, some molecules with a higher androgenic potency than others, attenuate the beneficial effects of estrogens on the lipid profile and the vasomotion as well. On the other hand, other progestins devoid of androgenic properties do not exert these deleterious effects. The epidemiological data does not suggest any negative effect of the progestins administered together with estrogens on cardiovascular morbidity or mortality. However, recent results suggest that in women with established coronary heart disease (CHD), HRT may not protect against further heart attacks, when the progestin selected possesses androgenic properties. Complying with the classic contra indications of HRT and selecting molecules devoid of estrogenic, androgenic, or glucocorticoid effect should allow a larger use of the progestins without any major drawback.

The metabolic consequences of treating postmenopausal women with non-oral hormone replacement therapy

OBJECTIVE

To define the metabolic profile of postmenopausal hormone replacement therapies when delivered through gels, patches, implants or other non-oral routes. Such information may be useful in the absence of reliable clinical data on the effects of these therapies on the risk of cardiovascular disease.

DESIGN AND METHODS

Selective literature review.

PATIENTS

Postmenopausal women.

RESULTS

Non-oral oestrogen therapies fail to invoke the hepatic response associated with oral therapy. Changes in hepatic protein synthesis are minimal and so plasma levels of binding globulins and other proteins tend to be normal. Many of the perturbations of the haemostatic system seen with oral therapy are avoided. In the absence of hepatic over-synthesis of apolipoproteins, plasma lipoprotein levels are unchanged or reduced. The direct effects of oestrogen on vascular function are apparent when the hormone is administered non-orally.

CONCLUSIONS

The net effect of non-oral estrogen therapies on the risk of cardiovascular disease is difficult to predict on the basis of current data. Some changes in plasma lipoprotein levels, such as the reduced fasting levels of triglycerides, would be considered desirable, but the cardioprotective increase in levels of high-density lipoproteins is absent. The differential effect on haemostasis markers is promising, but preliminary data relating to transdermal patches fail to support the idea that non-oral therapies will avoid the increased risk of venous thromboembolism associated with oral therapy. The ability of non-oral therapies to improve vascular function implies that they will offer postmenopausal women at least some of the cardiovascular protection seen with oral therapy.

Estrogen replacement therapy and exercise performance in postmenopausal women with coronary artery disease

We treated 10 postmenopausal women with stable angina, positive exercise test, and documented coronary artery disease with oral conjugated equine estrogen (0.625 mg/day of Premarin) or placebo for 4 weeks, in random order, with crossover after a 4-week washout period. Exercise tests, performed after each treatment period while the patients were taking their usual antianginal drugs showed no differences; thus, short-term estrogen does not improve exercise-induced ischemia compared with placebo.