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

EMAS position statement: Managing the menopause in the context of coronary heart disease

INTRODUCTION

Cardiovascular disease (CVD) including coronary heart disease (CHD) and stroke is the most common cause of female death. Premenopausal CHD is very rare but when women enter the menopause the incidence of CHD increases markedly. CHD presents 10 years later in women than in men. The reason is still unclear but the protective effects of estrogens have been suggested.

AIMS

To formulate a position statement on the management of menopause women in the context of coronary heart disease.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSIONS

Based on long term randomized placebo-controlled studies hormone therapy (HT) is not recommended for the primary or secondary prevention of CHD in postmenopausal women. In most countries the only indication for HT is the treatment of menopausal symptoms. Women with known CHD or with many coronary risk factors seeking HT because of troublesome climacteric symptoms should be evaluated for their individual baseline risk of developing breast cancer, venous thromboembolism and CHD recurrence. The same applies to non hormone therapy-based treatments where long term clinical studies are lacking. Risks should be weighed against expected benefit from symptom relief and improved quality of life. The lowest effective estrogen dose should be used during the shortest possible time. Transdermal administration is preferred if risk factors for VTE exist. Different progestogens might differ in their cardiovascular effects. Observational studies suggest that micronized progesterone or dydrogesterone may have a better risk profile than other progestogens with regard to thrombotic risk.

Does body mass index, smoking, lipoprotein levels, surgically induced menopause, hormone replacement therapy, years since menopause, or age affect hemostasis in postmenopausal women?

BACKGROUND

Controversy still exists as to the relative importance of menopausal status and lifestyle factors for the risk of coronary heart disease in women.

OBJECTIVE

The purpose of this study was to assess the influence of body mass index (BMI), smoking,lipoprotein levels, surgically induced menopause, hormone replacement therapy (HRT), years since menopause, and age on hemostasis in apparently healthy postmenopausal women.

METHODS

Lipoproteins (total cholesterol [TC], low-density lipoprotein cholesterol, high-density lipoprotein cholesterol [HDL-C], triglycerides [TG]), and hemostatic factors (fibrinogen, von Willebrand factor antigen [vWFag], coagulation factors VIIag [FVIlag] and VIIa [FVIIa], plasminogen activator inhibitor 1 [PAI-1]) were each measured once. A forward, stepwise, multiple regression analysis was used to assess variations in hemostatic parameters.

RESULTS

A group of 292 healthy Stockholm women recruited from the census register participated in the Stockholm Female Coronary Risk Study as controls. Of these women, 260 participated in the present study. BMI, smoking, lipoprotein levels, surgically induced menopause, and years since menopause (1-5 y) were found to be associated with a 31% increase in fibrinogen levels. A 7% increase in FVIIa levels was attributed to TC, BMI, and HRT. Years since menopause (1-15 y), TG, TC, BMI, and HRT were associated with an increase of up to 26% in FVIIag levels. A 9% increase in vWFag correlated with HDL-C and years since menopause (1-10, 11-14, and > or =15 y). BMI and TG explained a 21% and 3% increase, respectively, in PAI-1 levels. Neither the use of HRT nor years since menopause had any influence on hemostasis.

CONCLUSION

BMI, high levels of TC and TG, and low HDL-C levels appear to be more important than hormonal status in their impact on hemostatic variables in healthy postmenopausal women.

Androgens and coronary artery disease

A significant and independent association between endogenous testosterone (T) levels and coronary events in men and women has not been confirmed in large prospective studies, although cross-sectional data have suggested coronary heart disease can be associated with low T in men. Hypoandrogenemia in men and hyperandrogenemia in women are associated with visceral obesity; insulin resistance; low high-density lipoprotein (HDL) cholesterol (HDL-C); and elevated triglycerides, low-density lipoprotein cholesterol, and plasminogen activator type 1. These gender differences and confounders render the precise role of endogenous T in atherosclerosis unclear. Observational studies do not support the hypothesis that dehydroepiandrosterone sulfate deficiency is a risk factor for coronary artery disease. The effects of exogenous T on cardiovascular mortality or morbidity have not been extensively investigated in prospective controlled studies; preliminary data suggest there may be short-term improvements in electrocardiographic changes in men with coronary artery disease. In the majority of animal experiments, exogenous T exerts either neutral or beneficial effects on the development of atherosclerosis. Exogenous androgens induce both apparently beneficial and deleterious effects on cardiovascular risk factors by decreasing serum levels of HDL-C, plasminogen activator type 1 (apparently deleterious), lipoprotein (a), fibrinogen, insulin, leptin, and visceral fat mass (apparently beneficial) in men as well as women. However, androgen-induced declines in circulating HDL-C should not automatically be assumed to be proatherogenic, because these declines may instead reflect accelerated reverse cholesterol transport. Supraphysiological concentrations of T stimulate vasorelaxation; but at physiological concentrations, beneficial, neutral, and detrimental effects on vascular reactivity have been observed. T exerts proatherogenic effects on macrophage function by facilitating the uptake of modified lipoproteins and an antiatherogenic effect by stimulating efflux of cellular cholesterol to HDL. In conclusion, the inconsistent data, which can only be partly explained by differences in dose and source of androgens, militate against a meaningful assessment of the net effect of T on atherosclerosis. Based on current evidence, the therapeutic use of T in men need not be restricted by concerns regarding cardiovascular side effects. Available data also do not justify the uncontrolled use of T or dehydroepiandrosterone for the prevention or treatment of coronary heart disease.

Acute effects of transdermal estrogen in postmenopausal women with coronary artery disease. Using a clinically relevant estrogen dose and concurrent antianginal therapy

In the present study the acute anti-ischemic effect of clinically relevant doses of transdermal estradiol during concurrent antianginal therapy was investigated in 14 postmenopausal women with stable coronary artery disease. Plasma estradiol was significantly increased, but no significant effects on time to angina, time to 1 mm S--T depression, total exercise time, maximum rate-pressure product, maximum S--T depression or maximum workload were found. However, resting diastolic blood pressure was significantly decreased due to estrogen.

CME Paper: Hormone Replacement Therapy for Prevention or Treatment of Atherosclerosis in Postmenopausal Women: Promises, Controversies, and Clinical Trials

Cardiovascular disease is the leading cause of death among men and women in the U.S. and other developed societies. However, myocardial infarction and stroke are uncommon in women until their sixth decade and beyond. Clinicians have long suspected that the delay of a decade or more in cardiovascular disease expression in women relative to men is due to the protective effects of estrogen prior to menopause. Reports from population based observational studies of the favorable effects of hormone replacement therapy on cardiovascular morbidity and mortality have led to enthusiasm for widespread use of estrogen by postmenopausal women for the prevention of cardiovascular disease. In support of the antiatherogenic potential of estrogen are studies in postmenopausal women showing favorable effects on lipoprotein levels, fibrinolysis, and vascular function. However, a secondary prevention trial in postmenopausal women with coronary artery disease showed no cardiovascular benefit of hormone replacement therapy. Ongoing clinical trials and options to conventional hormone replacement therapy for cardiovascular protection will be discussed in this review. (c)2000 by CVRR, Inc.

Hormone replacement therapy and cardiovascular disease

This year's work on hormone replacement therapy (HRT) and cardiovascular disease has been remarkable for the publication of the first randomised controlled trial of HRT use, the Heart Estrogen Replacement Study (HERS). The findings go against not only the trend of previous observational epidemiological studies, but also against findings in the very many studies which have previously shown and continue to show this year a beneficial effect of HRT on a large variety of cardiovascular risk factors, including endothelial function, here reviewed. The aspect of the effect of HRT on clotting variables is clearly crucial given the increased risk of venous thrombosis, and also increased number of cardiac events in the first 4 months of the HERS. Prothrombotic factors increase with age in women, and HRT alters these, particularly fibrinogen, factor VII, and PAI (less change with transdermal HRT) and antithrombin III. In normal women therefore the balance should be towards fibrinolysis rather than coagulation. Work has been presented in abstract for clarifying the effects of HRT on coagulation markers and grasping the problem of differences according to its route of administration. The full publications on this work are expected shortly. We are still awaiting evidence from randomized controlled trials of HRT in primary prevention; one is now recruited but will not report until 2005.

Hormone replacement therapy and cardiovascular disease

A large amount of research continues to be conducted on the mechanisms of hormone replacement therapy (HRT) effects, and the first of the large clinical trials published its results during the past year. In addition to the well known effects on LDL-cholesterol, HDL-cholesterol, and triglycerides, recent studies confirmed that estrogen with or without a progestin lowers lipoprotein (a) concentrations in women (but not in men). In men, estrogen appears to have a similar effect on other lipids and lipoproteins and on plasminogen activator inhibitor-1 as in women. A comparison of estrogen with simvastatin indicated that simvastatin is better at lowering LDL-cholesterol while estrogen is better at raising HDL-cholesterol; when given in combination the additional effects were modest. Estrogen and simvastatin had similar beneficial effects on endothelial function. The estrogen effect on endothelial function may be blocked by medroxyprogesterone, but the data are inconsistent. These studies of intermediate outcomes were put in perspective by the results of a landmark secondary prevention trial of coronary heart disease (CHD). This randomized placebo-controlled trial (Heart and Estrogen/Progestin Replacement Study) of conjugated equine estrogens plus medroxyprogesterone failed to show the anticipated reduction in CHD, and at the same time the threefold increase in venous thromboembolism confirmed that HRT is procoagulant. Therefore, it is still not known whether HRT is a viable option for the prevention of CHD. The preliminary data on selective estrogen receptor modulators are not overly promising, but a definitive trial to test whether raloxifene will reduce CHD is ongoing.

A randomized trial on effects of hormone therapy on ambulatory blood pressure and lipoprotein levels in women with coronary artery disease

OBJECTIVE

To investigate 1-year effects of hormone replacement therapy (HRT) on ambulatory blood pressure (ABP) and lipoprotein levels in postmenopausal women with coronary artery disease (CAD).

METHODS

Sixty patients at a mean age (+/- SD) of 59 +/- 7 years were randomized into three groups: conjugated equine oestrogens (CEE) 0.625 mg daily (n = 20), 50 microg 17beta-oestradiol transdermally (TTSE) per 24 h (n = 20) or placebo (n = 20) for 18 days, then combined with medroxyprogesterone acetate 5 mg for 10 days. Each cycle of 28 days was repeated for one year.

RESULTS

Night-time systolic ABP had decreased by 9.6% (P= 0.0075) in 15 of 18 women in the CEE group and by 22% in 12 of 13 women (P = 0.0034) in the placebo group after 1 year. In the CEE group, a 4.6% rise in daytime systolic ABP (P< 0.05) and a 4.2% rise in night-time systolic ABP (P< 0.05) appeared from baseline to 6 months in 13 of 18 women. In the CEE group (14 women analysed), high-density lipoprotein levels showed a 15.8% increase (P= 0.0018) in 13 women, low-density lipoprotein levels a 15.2% decrease (P= 0.0129) in 12 women and total cholesterol levels a 7.5% decrease (P = 0.057) in 11 women after 1 year. Triglyceride levels showed no changes. In the TTSE group and in the placebo group, with 12 and 13 women analysed respectively, no significant changes appeared.

CONCLUSIONS

One year of HRT in patients with CAD does not influence ABP. Oral HRT induces beneficial effects on lipoprotein levels.

The acute effects of sublingual 17beta-estradiol on the cardiovascular system

The beneficial effects of estrogen in postmenopausal women have been well documented. Cardioprotection by estrogen, which is probably the result of several metabolic alterations, appears after 2 or more years of constant use. However, acute administration of estrogen (intravenous or intracoronary) was found to improve cardiac hemodynamics and function through various non-genomic mechanisms. This article reviews data on the consequences of sublingual administration of estrogen, a non-invasive and simple dosing route which is associated with rapid absorption and prompt cardiovascular reactions. It appears that sublingual estradiol at 1 or 2 mg may improve ischemia and exercise performance in women with coronary artery disease, and augment the aortic and brachial blood flow as a result of vasodilation, whereas larger doses (4 mg) may lead to a decrease in myocardial contractility and aortic blood flow, and a slight drop in blood pressure. More data are needed to evaluate the actual clinical significance of sublingual estradiol in healthy women, in situations when endothelial dysfunction is anticipated (diabetes, hypertension) and in women with diagnosed coronary artery disease.

Postmenopausal hormone use for cardioprotection: what we know and what we must learn

Coronary heart disease is a highly prevalent and lethal illness for women, particularly in their menopausal years, a fact that fostered interest in hormone use for cardioprotection. Despite the compelling evidence of cardiovascular benefit of estrogen therapy and estrogen and progestin therapy in observational studies of postmenopausal women, and multiple biologically plausible mechanisms for estrogen benefit, precise clinical outcome information from prospective randomized controlled trials is lacking. The only such trial reported, the Heart and Estrogen/Progestin Replacement Study, not only failed to demonstrate cardioprotection, but showed an early adverse outcome in women with documented coronary heart disease who received daily conjugated equine estrogen and medroxy-progesterone acetate. Several large randomized clinical trials of hormone and selective estrogen receptor moderator therapy for primary and secondary prevention are currently underway.

Treatment of stable angina

Severe atherosclerotic narrowing of one or more coronary arteries is responsible for myocardial ischemia and angina pectoris in most patients with stable angina pectoris. The coronary arteries of patients with stable angina also contain many nonobstructive plaques, which are prone to fissures or rupture resulting in presentation of acute coronary syndromes (unstable angina, myocardial infarction, sudden ischemic death). In addition to symptomatic relief of symptoms and an increase in angina-free walking time with antianginal drugs or revascularization procedures, the recent emphasis of treatment has been to reduce adverse clinical outcomes (coronary death and myocardial infarction). The role of smoking cessation, aspirin, treatment of elevated lipids, and treatment of high blood pressure in all patients and of beta-blockers and angiotensin-converting enzyme inhibitors in patients with diminished systolic left ventricular systolic function in reducing adverse outcomes has been well established. What is unknown, however, is whether any anti-anginal drugs (beta-blockers, long-acting nitrates, calcium channel blockers) effect adverse outcomes in patients with stable angina pectoris. Recent trials evaluated the usefulness of suppression of ambulatory ischemia in patients with stable angina pectoris, but it remains to be established whether suppression of ambulatory myocardial ischemia with antianginal agents or revascularization therapy is superior to pharmacologic therapy targeting symptom relief. Patients who have refractory angina despite optimal medical treatment and are not candidates for revascularization procedures may be candidates for newer techniques of transmyocardial revascularization, enhanced external counterpulsation, spinal cord stimulation, or sympathectomy. The usefulness of these techniques, however, needs to be confirmed in large randomized clinical trials.