Estrogen is associated with improved survival in aging women with congestive heart failure: analysis of the vesnarinone studies

Bazi Bushen capsule attenuates cardiac systolic injury via SIRT3/SOD2 pathway in high-fat diet-fed ovariectomized mice

Background

Bazi Bushen capsule (BZBS) is a Chinese herbal compound that is clinically used to treat fatigue and forgetfulness. However, it is still unclear whether and how BZBS affects heart function decline in menopausal women. This study aimed to examine the effect of BZBS on cardiac function in a high-fat diet-fed ovariectomy (HFD-fed OVX) mouse model and elucidate the underlying mechanism of this effect.

Methods

The experimental animals were divided into five groups: sham group, HFD-fed OVX group, and BZBS (0.7, 1.4, 2.8 g/kg) intervention groups. Senescence β-galactosidase staining and echocardiography were used to evaluate cardiac function. SwissTargetPrediction, KEGG and GO enrichment analyses were used to screen the underlying mechanism of BZBS. The morphological and functional changes in cardiac mitochondria and the underlying molecular mechanism were assessed by transmission electron microscopy, western blotting and biochemical assays. STRING database was used to analysis protein-protein interaction (PPI) network. Molecular docking studies were employed to predict the interactions of specific BZBS compounds with their protein targets.

Results

BZBS treatment ameliorated cardiac senescence and cardiac systole injury in HFD-fed OVX mice. GO and KEGG analyses revealed that the 530 targets of the 14 main components of BZBS were enriched mainly in the oxidative stress-associated pathway, which was confirmed by the finding that BZBS treatment prevented abnormal morphological changes and oxidative stress damage to cardiac mitochondria in HFD-fed OVX mice. Furthermore, the STRING database showed that the targets of BZBS were broadly related to the Sirtuins family. And BZBS upregulated the SIRT3 and elevated the activity of SOD2 in the hearts of HFD-fed OVX mice, which was also verified in vitro. Additionally, we revealed that imperatorin and osthole from the BZBS upregulated the expression of SIRT3 by directly docking with the transcription factors HDAC1, HDAC2, and BRD4, which regulate the expression of SIRT3.

Conclusion

This research shows that the antioxidative effect and cardioprotective role of BZBS on HFD-fed OVX mice involves an increase in the activity of the SIRT3/SOD2 pathway, and the imperatorin and osthole of BZBS may play central roles in this process.

Association between estrogen replacement therapy and heart failure in postmenopausal women: A systematic review and meta-analysis

BACKGROUND

Based on past epidemiological investigations, the cardiovascular role of estrogen replacement therapy (ERT) in postmenopausal women has always been controversial. The real efficacy of ERT for heart failure (HF) among postmenopausal women remains to be further investigated. This article is based on research into European and American populations.

PURPOSE

To determine the impact of estrogen replacement therapy on HF using meta-analysis.

METHODS AND MATERIAL

Electronic literature was searched on Web of Science, PubMed, and Embase databases to identify randomized controlled trials (RCTs) comparing the hospitalization for heart failure between ERT users and non-users among postmenopausal women. Pairs of reviewers screened eligible articles independently, extracted data, and evaluated the risk of bias. Summary relative risks were estimated for the composite endpoint of first hospitalized heart failure and admission to the hospital for heart failure.

RESULTS

A pooled study of five randomized controlled trials found that estrogen replacement therapy had no significant effect on the composite endpoint in postmenopausal women, with a relative risk of 1.02 (95% CI 0.94-1.10).

CONCLUSION

This systematic review demonstrated that estrogen replacement therapy did not significantly change the risk of first hospitalized heart failure and admission to the hospital for heart failure in postmenopausal women.

Hormone Therapy in Menopause: Concepts, Controversies, and Approach to Treatment

Hormone therapy (HT) is an effective treatment for menopausal symptoms, including vasomotor symptoms and genitourinary syndrome of menopause. Randomized trials also demonstrate positive effects on bone health, and age-stratified analyses indicate more favorable effects on coronary heart disease and all-cause mortality in younger women (close proximity to menopause) than in women more than a decade past menopause. In the absence of contraindications or other major comorbidities, recently menopausal women with moderate or severe symptoms are appropriate candidates for HT. The Women's Health Initiative (WHI) hormone therapy trials-estrogen and progestin trial and the estrogen-alone trial-clarified the benefits and risks of HT, including how the results differed by age. A key lesson from the WHI trials, which was unfortunately lost in the posttrial cacophony, was that the risk:benefit ratio and safety profile of HT differed markedly by clinical characteristics of the participants, especially age, time since menopause, and comorbidity status. In the present review of the WHI and other recent HT trials, we aim to provide readers with an improved understanding of the importance of the timing of HT initiation, type and route of administration, and of patient-specific considerations that should be weighed when prescribing HT.

Age-related alterations in cardiac and arterial structure and function in hypertensive women and men

The study was to compare age‐related alterations in cardiac and arterial structure and function by sex and to explore the impacts of achieved systolic blood pressure (SBP; <130 mm Hg vs. <140 mm Hg) level on age‐related alterations in cardiac and arterial structure and function in hypertensive women and men. Community hypertensive individuals without cardiovascular disease who had echocardiographic examination were included. Age‐related alterations in cardiac and arterial structure and function were compared by sex, and interplay between age and sex was analyzed according to achieved SBP level. The mean age of the cohort was 66.5 years, and women accounted for 62% (n = 602) of the cohort (n = 971). Compared to men, women had worse left ventricular (LV) diastolic function and greater LV and arterial stiffness. After adjusting for covariates, the magnitude of the associations between age with septal E/e′ ratio, septal S′ velocity, effective arterial elastance (Ea) and LV end‐diastolic elastance (Eed) were greater in women. Sex differences in the magnitude of association between age with these four indices varied according to achieved SBP level. When achieved SBP <130 mm Hg, the magnitude of the associations between age with septal E/e′ ratio, septal S′ velocity, Ea and Eed did not differ by sex. Since age and sex are non‐modifiable, achieving SBP target, especially at a lower level, might be beneficial to attenuate sex differences in age‐related alterations in cardiac and arterial structure and function.

Association between oral contraceptive use and incident heart failure

Aims

Oral contraceptives (OCs) are widely used in women of reproductive age, but their influences on heart failure (HF) development have yet to be reported. This study was performed to assess HF risk associated with OC use.

Methods and results

We studied women participating in the Multi‐Ethnic Study of Atherosclerosis with available data on OC use. Inverse probability of treatment weighting analyses were used to reduce baseline imbalances. Cox proportional hazards models were applied to evaluate the associations of OC use and HF risk. The primary analysis comprised a total of 3594 participants [average age 62.10 (10.24) years]. During an average follow‐up of 12.45 (3.75) years, 138 incident HF occurred. In unadjusted Cox model, OC use was associated with a decreased risk of HF [hazard ratio (HR) = 0.45, 95% confidence interval (CI) 0.31–0.64, P < 0.001]. However, in multivariable‐adjusted and inverse probability of treatment weighting models, the results were attenuated and became non‐significant (HR = 0.96, 95% CI 0.63–1.48, P = 0.86 and HR = 0.79, 95% CI 0.45–1.40, P = 0.43, respectively). Duration of OC use was not related to increased risks of HF. When stratifying HF into subtypes, similar associations were observed. In multivariable–adjusted regression models, OC use was positively associated with left ventricular end‐diastolic mass [coefficient (β) = 3.04, P = 0.006] and stroke volume (β = 1.76, P = 0.01 for the left ventricle; β = 2.17, P = 0.005 for the right ventricle) but had no impact on left ventricular ejection fraction (β = 0.09, P = 0.75) and right ventricular ejection fraction (β = 0.33, P = 0.25).

Conclusions

Oral contraceptive use in women of reproductive age does not portend increased risk of HF. However, whether the formulations or dosages differently impact this association should be further investigated.

Poor Neurological Deficit Was an Independent 30-day Risk Factor in Symptomatic Carotid Stenosis after CEA with Selective Shunting

BACKGROUND

Carotid endarterectomy (CEA) prevents the occurrence of stroke in the future, although its efficacy depends on the detection and control of high perioperative risk factors. We aimed to analyze the association between preoperative neurological deficit and the 30-day risk of major adverse cardiovascular events (MACEs) in CEA with selective shunting for symptomatic carotid stenosis.

METHODS

We assessed 653 patients who underwent CEA with selective shunting for symptomatic carotid stenosis between August 2011 and August 2019. The primary outcomes of the study were the occurrence of MACEs, defined as stroke (ischemic stroke or cerebral hemorrhage), all-cause mortality, and myocardial infarction during the perioperative period after CEA. Baseline patient characteristics were analyzed to identify factors associated with perioperative (<30 days) MACEs. Multivariable logistic regression models were used to estimate the association between preoperative modified Rankin Scale (mRS) and the 30-day risk of MACEs. Interaction and stratified analyses were conducted according to age, drinking, history of hypertension and coronary artery disease, and surgical side.

RESULTS

The mean age of patients was 68.7 ± 9.1 years, and 86.4% were men. The 30-day MACEs rate was 2.5%. In univariate logistic regression, histories of coronary artery disease (odds ratio (OR), 2.57 [95% confidence interval (CI), 1.04-6.34]), a severe contralateral carotid stenosis or occlusion (OR, 4.52 [95% CI, 1.84-11.11]), and a poor neurological deficit (mRS ≥ 3 versus mRS < 3: OR, 3.78 [95% CI, 1.21-11.82]) were associated with higher primary outcome rates. A history of hypertension did not increase the risk of MACEs (OR, 0.37 [95% CI, 0.15-0.89]). In the multivariable regression analysis, poor neurological deficit was associated with a higher risk of the MACEs within 30 days (mRS ≥ 3 versus mRS < 3: 11.1% vs. 2.0%, adjusted OR 5.70 [95% CI, 1.50-21.60]). The interaction analysis revealed no interactive role in the association between neurological deficit and 30-day risk of MACEs.

CONCLUSIONS

Poor neurological deficit was an independent risk factor associated with the 30-day risk of MACEs in symptomatic patients who underwent CEA with selective shunting. Our findings may provide guidance to surgeons when treating patients with poor neurological deficit. The decision to perform surgery should be made after careful consideration.

Estrogen Receptor-α Non-Nuclear Signaling Confers Cardioprotection and Is Essential to cGMP-PDE5 Inhibition Efficacy

Using genetically engineered mice lacking estrogen receptor-α non-nuclear signaling, this study demonstrated that estrogen receptor-α non-nuclear signaling activated myocardial cyclic guanosine monophosphate-dependent protein kinase G and conferred protection against cardiac remodeling induced by pressure overload. This pathway was indispensable to the therapeutic efficacy of cyclic guanosine monophosphate-phosphodiesterase 5 inhibition but not to that of soluble guanylate cyclase stimulation. These results might partially explain the equivocal results of phosphodiesterase 5 inhibitor efficacy and also provide the molecular basis for the advantage of using a soluble guanylate cyclase simulator as a new therapeutic option in post-menopausal women. This study also highlighted the need for female-specific therapeutic strategies for heart failure.

ERβ selective agonist inhibits angiotensin-induced cardiovascular pathology in female mice

Cardiac hypertrophy in humans can progress to cardiac failure if the underlying impetus is poorly controlled. An important direct stimulator of hypertrophy and its progression is the angiotensin II (AngII) peptide. AngII also causes hypertension that indirectly contributes to cardiac hypertrophy. Others and we have shown that estrogens acting through the estrogen receptor (ER)-β can inhibit AngII-induced or other forms of cardiac hypertrophy in mice. However, the proliferative effects of estrogen in breast and uterus that promote the development of malignancy preclude using the steroid to prevent cardiac disease progression. We therefore tested whether an ERβ selective agonist, β-LGND2, can prevent hypertension and cardiac pathology in female mice. AngII infusion over 3 weeks significantly stimulated systolic and diastolic hypertension, cardiac hypertrophy, and cardiac fibrosis, all significantly prevented by β-LGND2 in wild-type but not in ERβ genetically deleted mice. AngII stimulated the Akt kinase to phosphorylate and inhibit the glycogen synthase kinase-3β kinase, leading to GATA4 transcription factor activation and hypertrophic mRNA expression. As a novel mechanism, all these actions were opposed by estradiol and β-LGND2. Our findings provide additional understanding of the antihypertrophic effects of ERβ and serve as an impetus to test specific receptor agonists in humans to prevent the worsening of cardiovascular disease.

Heart failure in women

Heart failure (HF) has steadily increased in prevalence and affects both males and females equally. Despite this, there has been a significant underrepresentation of women in large scale HF trials. This disparity has lead to a deficit in understanding important gender-based differences in pathophysiology, diagnosis and treatment strategies. We review these gaps and explore a biological basis for varying outcomes. Endogenous estrogen plays an important role in epidemiology and outcome. The administration of exogenous estrogen has had varied success in treatment and is outlined extensively below. Additionally, we highlight unique HF syndromes through pregnancy and important sex-specific issues concerning transplant and mechanical circulatory support. A central theme remains: there is a clear need for increased female recruitment in clinical trials, and more studies exploring the role of gender-based biology in HF treatment.

Estrogen and the cardiovascular system

Estrogen is a potent steroid with pleiotropic effects, which have yet to be fully elucidated. Estrogen has both nuclear and non-nuclear effects. The rapid response to estrogen, which involves a membrane associated estrogen receptor(ER) and is protective, involves signaling through PI3K, Akt, and ERK 1/2. The nuclear response is much slower, as the ER-estrogen complex moves to the nucleus, where it functions as a transcription factor, both activating and repressing gene expression. Several different ERs regulate the specificity of response to estrogen, and appear to have specific effects in cardiac remodeling and the response to injury. However, much remains to be understood about the selectivity of these receptors and their specific effects on gene expression. Basic studies have demonstrated that estrogen treatment prevents apoptosis and necrosis of cardiac and endothelial cells. Estrogen also attenuates pathologic cardiac hypertrophy. Estrogen may have great benefit in aging as an anti-inflammatory agent. However, clinical investigations of estrogen have had mixed results, and not shown the clear-cut benefit of more basic investigations. This can be explained in part by differences in study design: in basic studies estrogen treatment was used immediately or shortly after ovariectomy, while in some key clinical trials, estrogen was given years after menopause. Further basic research into the underlying molecular mechanisms of estrogen's actions is essential to provide a better comprehension of the many properties of this powerful hormone.

Sex and gender differences in myocardial hypertrophy and heart failure

Cardiovascular disease is the most common cause of death in men and women worldwide. Men develop most, but not all, cardiovascular diseases at an earlier age while the number of affected women significantly increases with higher age. Heart failure (HF) is a common cause of cardiovascular death and carries a poor prognosis in both genders. Risk factors and myocardial adaptations in HF in men and women are different. Female hearts develop a more favorable physiological form of myocardial remodeling than male hearts. This may be related to sex hormones, estrogens and testosterone. A clinical study for gender differences in human aortic stenosis supports the hypotheses. HF management differs between both sexes, with underdiagnosis and undertreatment and less use of invasive therapies in women. Nevertheless, women frequently have better outcomes than men. Gender research will contribute directly to patient-oriented benefit by suggesting clinical protocols.

Heart failure in women: epidemiology, biology and treatment

Although women account for a significant proportion of the growing heart failure epidemic, they have been poorly represented in clinical trials. As emerging epidemiologic data reveal a growing prevalence and burden of disease among women, it is increasingly important that treating physicians and researchers recognize sex-based differences. Despite the overall incidence of heart failure being lower in women compared with men, the magnitude of improvement in survival over the last several decades has been less apparent in women. Women with heart failure are more likely to be older, have preserved systolic function and nonischemic cardiomyopathy. While clinical trials have demonstrated improved outcomes among heart failure patients, they have predominantly included men, yielding results that are sometimes inadequately powered to detect a benefit for women. Without adequate representation of women in clinical trials, one cannot assume that the same level of therapeutic evidence also applies to women. Nonetheless, it appears that beta-blockers and angiotensin-converting enzyme inhibitors provide the same survival benefits in women with systolic dysfunction as in men. In addition, some studies suggest that angiotensin-receptor blockers may lead to a better survival in women when compared with angiotensin-converting enzyme inhibitors. Focused research is needed to understand and guide the management of women with heart failure.

Hormone Replacement Therapy: A Critical Review

The aim of this chapter is to review the most recent aspects of hormone replacement therapy (HRT), and to clarify its impact on associated health conditions amidst growing uncertainties. Special emphasis has been placed on its effect on cardiovascular conditions and breast cancer, the two most important outcomes affected by HRT, and on identifying ideal candidates for HRT as well as defining the optimum new HRT regimens.

Gender-related dissociation in outcomes in chronic heart failure: reduced mortality but similar hospitalization in women

BACKGROUND

The impact of gender on major natural history endpoints in heart failure (HF) has not been examined in a propensity-matched study.

METHODS

Of the 7788 chronic systolic and diastolic HF patients in the Digitalis Investigation Group trial 1926 were women. Propensity scores for female gender were used to assemble a cohort of 1669 pairs of men and women who were well-balanced on 32 measured baseline characteristics. Matched hazard ratios (HR) and 95% confidence intervals (CI) for outcomes associated with female gender were calculated using stratified Cox regression models.

RESULTS

All-cause mortality occurred in 36% (rate, 1256/10,000 person-years) and 30% (rate, 1008/10,000 person-years) of matched men and women respectively during 5 years of follow up (HR when women were compared with men, 0.82, 95% CI, 0.72-0.94, P=0.004). Female gender was also associated with reduced cardiovascular mortality (matched HR, 0.85; 95% CI, 0.73-0.99, P=0.037) and a trend toward reduced non-cardiovascular mortality (matched HR, 0.73; 95% CI, 0.53-1.00; P=0.053). All-cause hospitalization occurred in 67% (rate, 4003/10,000 person-years) and 65% (rate, 3762/10,000 person-years) matched male and female patients respectively (HR for women, 1.03, 95% CI, 0.93-1.15, P=0.538). Female gender was not associated with cardiovascular or HF hospitalization but was associated with hospitalization due to unstable angina pectoris (matched HR, 1.38; 95%CI, 1.11-1.72; P=0.003) and stroke (matched HR, 0.65; 95%CI, 0.46-0.92; P=0.014).

CONCLUSIONS

In patients with chronic HF, female gender has a significant independent association with improved survival but has no association with all-cause, cardiovascular, or HF hospitalizations.

Age- and gender-specific changes in the left ventricular relaxation: a Doppler echocardiographic study in healthy individuals

BACKGROUND

Although left ventricular diastolic function has been shown to deteriorate with advancing age, its gender-specific change is unknown. The aim of this study was to investigate age- and gender-specific changes in tissue Doppler-derived left ventricular diastolic index, E'.

METHODS AND RESULTS

A total of 1333 healthy individual without known heart disease or hypertension (mean age, 55 years; range, 10 to 89) were enrolled and studied. Peak early mitral annular velocity (E') and peak late mitral annular velocity (A') were recorded and measured. As an index of the left ventricular relaxation, E' was used. As an index of the left ventricular filling pressure, E/E' was calculated. Although systolic indices poorly correlated with age, diastolic indices correlated well with age. Among those aged 30 to 39 and 40 to 49 years, E' was significantly lower in males than in females. In subjects aged 50 to 59 and 60 to 69 years, E' was similar in both genders. Among those aged 70 to 79 and 80 to 89 years, E' was significantly lower in females than in males. Predictors of the lowest quartile of E' among subjects aged >50 years were age (P<0.0001; chi(2)=66.11; odds ratio, 1.08; 95% CI, 1.058 to 1.097) and female gender (P=0.002; chi(2)=9.23; odds ratio, 1.68; 95% CI, 1.202 to 2.343).

CONCLUSIONS

Age-related changes in diastolic indices were gender specific. In the elderly population, diastolic function deteriorated more significantly in the female gender than in the male gender. These results may explain the relatively higher incidence in elderly females among patients with diastolic heart failure and higher cardiovascular mortality in the female gender.

Dose-dependent cardiac effect of oestrogen replacement in mice post-myocardial infarction

Hormonal replacement therapy (HRT) has recently been shown to increase the risk of cardiovascular events in women. However, it is not clear whether the adverse effect of HRT is related to dosage and/or the presence of progestin. Using a mouse model of myocardial infarction (MI), we studied the dose-effect of oestrogen replacement on mortality and cardiac remodelling and dysfunction post-MI in the absence of progestin. Six-week-old females were subjected to ovariectomy (OVX). A pellet containing a low, moderate or high dose of 17beta-oestradiol (E(2); 0.42, 4.2 or 18.8 microg day(-1)) or placebo was implanted subcutaneously on the day of OVX. Myocardial infarction was induced 8 weeks later, and cardiac morphology and function were evaluated 8 weeks after MI. We found that E(2) at moderate and high doses adversely affected mortality. A low dose of E(2) that restored plasma oestrogen close to physiological levels had no significant effect on mortality but tended to improve cardiac function and remodelling, associated with reduced fibrosis and increased capillary density. At the moderate dose, E(2) exacerbated cardiac fibrosis, hypertrophy, dysfunction and dilatation, associated with liver and kidney enlargement and ascites. Protein kinase C and extracellular signal-regulated kinase were increased by MI but were not affected by E(2). In summary, E(2) at a low dose tended to be cardioprotective. At increased doses that raised plasma oestrogen far beyond the physiological level, E(2) was detrimental to the heart. Our data suggest that dosage should be an important consideration when studying the effect of oestrogen replacement on the heart.

17 Beta-estradiol differentially affects left ventricular and cardiomyocyte hypertrophy following myocardial infarction and pressure overload

BACKGROUND

We have shown previously that 17beta-estradiol (E2) increases left ventricular (LV) and cardiomyocyte hypertrophy after myocardial infarction (MI). However, E2 decreases hypertrophy in pressure overload models. We hypothesized that the effect of estrogen on cardiac hypertrophy was dependent on the type of hypertrophic stimulus.

METHODS AND RESULTS

Ovariectomized wild-type female mice (n = 192) were given vehicle or E2 treatment followed by coronary ligation (MI), transverse aortic constriction (TAC), or sham operation. Signaling pathway activation was studied at 3, 24, and 48 hours, whereas echocardiography and hemodynamic studies were performed at 14 days. MI induced early but transient activation of p38 and p42/44 MAPK pathways, whereas TAC induced sustained activation of both pathways. E2 had no effect on these pathways, but increased Stat3 activation after MI while decreasing Stat3 activation after TAC. MI caused LV dilation and decreased fractional shortening (FS) that were unaltered by E2. TAC caused LV dilation, reduced FS, and increased LV mass, but in this model, E2 improved these parameters. After MI, E2 led to increases in myocyte cross-sectional area, atrial natriuretic peptide (ANP) and beta-myosin heavy chain (MHC) gene expression, but E2 diminished TAC-induced increases ANP and beta-MHC gene expression.

CONCLUSIONS

These data demonstrate that the effects of E2 on LV and myocyte remodeling depend on the nature of the hypertrophic stimulus. The opposing influence of E2 on hypertrophy in these models may, in part, result from differential effects of E2 on Stat3 activation. Further work will be necessary to explore this and other potential mechanisms by which estrogen affects hypertrophy in these models.

Myofilament response to Ca2+ and Na+/H+ exchanger activity in sex hormone-related protection of cardiac myocytes from deactivation in hypercapnic acidosis

Compared to sham-operated controls, myofilaments from hearts of ovariectomized (OVX) rats demonstrate an increase in Ca2+ sensitivity with no change in maximum tension (Wattanapermpool J and Reiser PJ. Am J Physiol 277: H467–H473, 1999). To test the significance of this modification in intact cells, we compared intracellular Ca2+ transients and shortening of ventricular myocytes isolated from sham and 10-wk OVX rats. There was a decrease in the peak Ca2+ transient with prolonged 50% decay time in OVX cardiac myocytes without changes in the resting intracellular Ca2+ concentration. Percent cell shortening was also depressed, and relaxation was prolonged in cardiac myocytes from OVX rats compared with shams. Ovariectomy induced a sensitization of the myofilaments to Ca2+. Hypercapnic acidosis suppressed the shortening of OVX myocytes to a lesser extent than that detected in shams. Moreover, a larger compensatory increase in %cell shortening was obtained in OVX myocytes during prolonged acidosis. The elevated compensation in cell shortening was related to a higher amount of increase in the amplitude of the Ca2+ transient in OVX myocytes. However, these differences in Ca2+ transients and %cell shortening were no longer evident in the presence of 1 μM cariporide, a specific inhibitor of Na+/H+ exchanger type 1 (NHE1). Our results indicate that deprivation of female sex hormones modulates the intracellular Ca2+ concentration in cardiac myocytes, possibly via an increased NHE1 activity, which may act in concert with Ca2+ hypersensitivity of myofilament activation as a determinant of sex differences in cardiac function.

Effect of estrogen on calcium-handling proteins, β-adrenergic receptors, and function in rat heart

Regulation of cellular Ca(2+) cycling is central to myocardial contractile function. Loss of Ca(2+) regulation is associated with cardiac dysfunction and pathology. Estrogen has been shown to modify contractile function and to confer cardioprotection. Therefore, we investigated the effect of estrogen on expression of rat heart myocardial Ca(2+)-handling proteins and beta-adrenergic receptor (beta(1)-AR) and examined functional correlates. Female rats were sham-operated (SHAM) or ovariectomized. Two weeks after ovariectomy rats were injected (i.p.) daily with estradiol benozoate (OVX+EB) or sesame oil (OVX) for 2 weeks. Protein abundance was measured by immunoblotting and mRNA was quantified by real-time RT-PCR. OVX significantly decreased estrogen and progesterone levels and EB replacement returned both estrogen and progesterone to physiological levels. OVX induced a 75% reduction of uterine weight and a gain in body weight. Replacement restored weights to SHAM level. OVX increased and estrogen-replacement normalized abundance of beta(1)-AR and L-type Ca(2+) channel (Cav1.2) protein. OVX decreased sodium-Ca(2+) exchange protein (NCX) and estrogen restored protein abundance to SHAM levels. Sarcoplasmic reticular ATPase (SERCA), phospholamban (PLB), and ryanodine receptor (RyR) abundance was not altered by hormone status. Levels of mRNA encoding for beta(1)-AR, Cav1.2, and NCX were not influenced by OVX or estrogen replacement. OVX had no effect on SERCA and PLB mRNA level but estrogen replacement elicited a significant increase compared to OVX and SHAM. Estrogen-dependent changes in Ca(2+)-handling proteins and beta(1)-AR are theoretically consistent reduced myocellular Ca(2+) load. However, hormone-dependent alterations in protein were not associated with changes in contractile function.

Myocardial infarction increases reactivity to phenylephrine in isolated aortic rings of ovariectomized rats

Clinical studies demonstrated that the incidence of cardiovascular disease is low in premenopausal women, rises in postmenopausal women, and is reduced to premenopausal levels in postmenopausal women who receive estrogen therapy. The interaction between gender and myocardial infarction indicates that the survival advantage of women is modified by the occurrence of myocardial infarction. Therefore, the effect of myocardial infarction on mortality is greater in women than men. The aim of our study was to investigate the influence of the ovariectomy on the reactivity to phenylephrine in aortic rings of female rats post-myocardial infarction. Animals were divided in four groups: Control (Cont), Ovariectomized (Ovx), Infarcted (Inf) and Ovariectomized and Infarcted (Ovx-Inf). Aortic rings were studied 60 days after ovariectomy and infarction surgery. The infarct area was similar among groups. The maximal response to phenylephrine was increased in the Ovx-Inf group compared to all the other groups (Cont = 2.411+/-0.131 (N = 11); Ovx = 2.863+/-0.121(N = 15); Inf = 2.794+/-0.102 (N = 13); Ovx-Inf = 3.40+/-0.201* (N = 12) g; *P < 0.05). In the absence of endothelium and L-NAME perfusion, the maximal response to phenylephrine was similarly increased in all groups. Relaxation to acetylcholine was also similar. The indirect evaluation of NO bioavailability analyzed by the area under the curve demonstrated a reduction on NO on the Ovx-Inf group that could contributes to increased response to phenylephrine. In conclusion our results showed that ovariectomy associated to a myocardial infarction leads to an increment of aorta reactivity to phenylephrine associated to a reduction of basal NO bioavailability in spite of a normal endothelium-dependent relaxation induced by acetylcholine.

17 Beta-estradiol improves survival in male mice with cardiomyopathy induced by cardiac-specific tumor necrosis factor-alpha overexpression

A transgenic mouse model of congestive heart failure (CHF) consequent to cardiac-specific overexpression of tumor necrosis factor-alpha (TNF-alpha) (TNF1.6) displays marked sex-related phenotypic differences. To clarify the potential contributions of estrogen to these sex-specific differences, male TNF1.6 mice were treated with 17beta- estradiol (E2). E2 treatment started at 25 +/- 1 days old (group A), but not at 36 +/- 2 days old (group B), significantly improved survival rate (p < 0.05). Furthermore, ventricular weight/body weight ratio was significantly decreased by E2 treatment in group A (p < 0.05). Echocardiography revealed that E2-treated hearts in group A exhibited less left ventricular dilatation (p < 0.05) relative to untreated male TNF1.6 mice (control). Moreover, in group A, E2 treatment partially reversed basal and isoproterenol-stimulated fractional shortening in TNF1.6 mice (p < 0.05). The cardiac content of TNF-alpha and interleukin-1beta (IL-1beta) was not changed by E2 treatment regardless of the timing of treatment. Thus, E2 exposure prior to puberty can limit the severity of cardiomyopathy in male TNF1.6 mice.

Gender Differences in Outcome of Conservatively Treated Patients With Asymptomatic High Grade Carotid Stenosis

Background and Purpose— Gender differences are currently becoming increasingly recognized as an important prognostic factor in patients with atherosclerotic disease. We investigated gender-related differences in vascular outcome and mortality of asymptomatic patients with high-grade internal carotid artery (ICA) stenosis.

Methods— We enrolled 525 consecutive patients (325 males with a median age of 72 years and 200 females with a median age of 75 years) from a single center registry who were initially treated conservatively with respect to a neurologically asymptomatic ≥70% ICA stenosis. Patients were followed-up for a median of 38 months (interquartile range, 18 to 65) for major adverse cardiovascular, cerebral, and peripheral vascular events (MACE: combined end point including myocardial infarction, stroke, [partial] limb amputation, and death), vascular mortality, and all-cause mortality.

Results— Cumulative MACE-free survival rates in males and females at 1, 3, and 5 years were 83%, 65%, 48% versus 85%, 73%, and 67% ( P =0.004), respectively. Adjusted hazard ratios for MACE, vascular mortality, and all-cause mortality for males were 1.96 ( P =0.016), 2.48 ( P <0.001), and 1.70 ( P =0.007) as compared with females, irrespective of age, vascular risk factors, comorbidities, and the individual risk status estimated by the American Society of Anesthesiologists (ASA) score.

Conclusion— Male patients with high-grade carotid artery stenosis are at a considerably higher risk for poor outcome than their female counterparts. In particular, the risk for fatal vascular events is substantially increased in males.

Effect of hormone therapy on mortality rates among women with heart failure and coronary artery disease

Randomized, controlled trial data from the Heart and Estrogen-progestin Replacement Study were used to evaluate the effect of estrogen plus progestin use on all-cause mortality in women with heart failure and coronary disease. Over the 4.1-year follow-up, estrogen plus progestin use had no effect on all-cause mortality (hazard ratio 1.0, 95% confidence interval 0.7 to 1.4, p = 0.8) in women with heart failure and coronary disease.

17β-Estradiol Reduces Cardiomyocyte Apoptosis In Vivo and In Vitro via Activation of Phospho-Inositide-3 Kinase/Akt Signaling

Female gender and estrogen-replacement therapy in postmenopausal women are associated with improved heart failure survival, and physiological replacement of 17β-estradiol (E2) reduces infarct size and cardiomyocyte apoptosis in animal models of myocardial infarction (MI). Here, we characterize the molecular mechanisms of E2 effects on cardiomyocyte survival in vivo and in vitro. Ovariectomized female mice were treated with placebo or physiological E2 replacement, followed by coronary artery ligation (placebo-MI or E2-MI) or sham operation (sham) and hearts were harvested 6, 24, and 72 hours later. After MI, E2 replacement significantly increased activation of the prosurvival kinase, Akt, and decreased cardiomyocyte apoptosis assessed by terminal deoxynucleotidyltransferase dUTP nick-end labeling (TUNEL) staining and caspase 3 activation. In vitro, E2 at 1 or 10 nmol/L caused a rapid 2.7-fold increase in Akt phosphorylation and a decrease in apoptosis as measured by TUNEL staining, caspase 3 activation, and DNA laddering in cultured neonatal rat cardiomyocytes. The E2-mediated reduction in apoptosis was reversed by an estrogen receptor (ER) antagonist, ICI 182,780, and by phospho-inositide-3 kinase inhibitors, LY294002 and Wortmannin. Overexpression of a dominant negative-Akt construct also blocked E2-mediated reduction in cardiomyocyte apoptosis. These data show that E2 reduces cardiomyocyte apoptosis in vivo and in vitro by ER- and phospho-inositide-3 kinase–Akt–dependent pathways and support the relevance of these pathways in the observed estrogen-mediated reduction in myocardial injury.

Heart failure in women

Women who experience heart failure (HF) exhibit distinct differences from men. Because women are a minority in major HF trials and because diagnostic criteria have been variable in epidemiologic surveys, many questions remain unanswered. This article describes differences in sex hormone effects and responses to injury, pressure overload, and aging, which may account for differences observed in epidemiology, risk factors and causes, mechanisms for disease development, response to treatment, and outcomes. Hypertension,diastolic dysfunction, diabetes, obesity, and inactivity are more important factors in women, whereas ischemic heart disease and systolic dysfunction are more important factors in men. Women appear to benefit less from established treatments but have better survival. Future studies directed exclusively at women may be warranted to confirm or establish benefits of existing and future treatments.

Effect of postmenopausal hormone replacement therapy on cardiovascular performance

Postmenopausal hormone replacement therapy (HRT) has usually been evaluated the relationship with atherosclerotic disease, whereas its effect on direct cardiac functions hasn't been investigated in detail. This study was planned to investigate the long-term effects of HRT on cardiac functions and exercise performance.

METHODS

Thirty-six postmenopausal women (mean age: 51 +/- 4 years, 39-60 years) were prospectively analyzed with pulsed wave Doppler echocardiography and symptom-limited exercise stress test before HRT (oral 0.625 mg conjugated estrogen and 2.5 mg medroxyprogesteron acetate/day), and at the third and the sixth months. The effect of HRT on left ventricular ejection fraction (EF), early filling velocity (E wave) and late filling velocity (A wave), E wave deceleration time (EDT), E/A ratio, myocardial performance index (MPI), exercise duration and METS changes were examined.

RESULTS

HRT did not significantly alter the left ventricular EF. At the third month of HRT, there was an insignificant increase in E wave, EDT, and E/A ratio, whereas an insignificant decrease was noted in MPI (P > 0.05). However, at the sixth month of HRT, these changes became significant (68 +/- 12 vs. 75 +/- 13 cm/s, P < 0.01; 171 +/- 24 vs. 184 +/- 14 ms, P < 0.01; 1.01 +/- 0.23 vs. 1.11 +/- 0.27, P < 0.01, and 44 +/- 9 vs. 39 +/- 8%, P < 0.001, respectively). On the other hand, exercise duration and exercise METS values showed significant improvements at the third month of HRT (423 +/- 104 vs. 482 +/- 104 s, P < 0.001; 8.2 +/- 1.7 vs. 9.1 +/- 2 METS, P < 0.001). These improvements also continued at the sixth month of HRT. In conclusion, postmenopausal HRT leads to a progressive improvement on left ventricular function parameters, and in parallel, in exercise performance.

Sex differences in carotid plaque and stenosis

BACKGROUND AND PURPOSE

Women are relatively protected from cardiovascular events; they are 3 times as likely as men to survive to age 90 years. Although clinical trials show an excess of thrombotic events with estrogen/progestin hormone replacement therapy, much experimental and epidemiological evidence suggests that estrogen may have beneficial effects on endothelial function and atherosclerosis, raising the possibility of sex differences in arterial remodeling. We studied sex differences in carotid plaque and stenosis in relation to survival free of stroke, death, and myocardial infarction.

METHODS

A total of 1686 patients from an atherosclerosis prevention clinic were followed annually for up to 5 years (mean, 2.5+/-1.3 years) with baseline and follow-up measurements; there were 45 strokes, 94 myocardial infarctions, and 41 deaths.

RESULTS

Carotid stenosis and plaque increased with age. Women had greater stenosis compared with men (P=0.001), whereas men had greater plaque area than did women at all ages (P<0.0001). Stroke, myocardial infarction, and death combined were predicted significantly by plaque area (P=0.004) but not by stenosis (P=0.042).

CONCLUSIONS

Women have more stenosis but less plaque than men, suggesting that differences in sex hormones may affect remodeling of atherosclerosis. Plaque area was a stronger predictor of outcomes than was stenosis.

The short-term effects of different regimens of hormone replacement therapy on left ventricular structure and performance in healthy postmenopausal women. A prospective, controlled echocardiographic study

OBJECTIVE

To compare the short-term effects of different hormone replacement therapy (HRT) regimens on left ventricular structure and function in healthy postmenopausal women.

METHODS

Forty-two apparently healthy postmenopausal women were evaluated prospectively in this controlled study. Subjects were divided into 4 groups. Ten subjects, who did not accept HRT or any other treatments, formed the control group. The remaining subjects were assigned to receive oral estradiol (2 mg/day) + norethisterone acetate (1 mg/day) (n = 11), transdermal estradiol (0.05 mg) + norethisterone acetate (0.25 mg) (n = 11) or tibolone (2.5 mg/day) (n = 10) therapy during 12 weeks. Echocardiography and Doppler techniques were used to assess the cardiac effects of different HRT regimens.

RESULTS

After 12 weeks of treatment, there were significant increases in left ventricular ejection fraction (transdermal group: p = 0.008, oral group: p = 0.003, tibolone group: p = 0.005) and cardiac output (transdermal group: p = 0.003, oral group: p = 0.003, tibolone group: p = 0.021) in all treatment groups. In addition, in the transdermal group, a slight increase in left ventricular end-diastolic volume was significant (p = 0.046).

CONCLUSION

These data suggest that oral and transdermal HRT regimens and tibolone may contribute to the improvement in left ventricular systolic function without having an effect on left ventricular structure after short-term administration in healthy postmenopausal women.

Hormone replacement therapy is associated with improved survival in women with advanced heart failure

OBJECTIVES

We sought to determine whether hormone replacement therapy (HRT) is associated with an improved prognosis in women with advanced heart failure (HF) and systolic dysfunction.

BACKGROUND

There are about two million postmenopausal women in the U.S. with HF. However, limited data are available to assess the effects of HRT on survival in this large group of patients.

METHODS

A retrospective analysis of women age 50 years and over entered into the Beta-Blocker Evaluation of Survival Trial (BEST) was conducted using Cox regression analysis comparing survival in HRT users and non-users after correcting for baseline variables known to predict survival in women with HF and systolic dysfunction.

RESULTS

In 493 women age 50 years and older, HRT was associated with a significant reduction in mortality-21% mortality in HRT users and 34% in non-users (p = 0.025). Multivariate analysis demonstrated a hazard ratio for mortality of 0.6 (95% confidence interval = 0.36 to 0.97) (p = 0.039) for HRT users. The benefits of HRT were noted only in women with a nonischemic etiology of HF (n = 237).

CONCLUSIONS

Hormone replacement therapy is associated with a marked improvement in survival in postmenopausal women with advanced HF. A prospective, randomized trial of HRT should be performed in this large group of patients.

Gender differences in the expression of heat shock proteins: the effect of estrogen

The heat shock proteins (HSPs) are an important family of endogenous, protective proteins that are found in all tissues. In the heart, HSP72, the inducible form of HSP70, has been the most intensely studied. It is well established that HSP72 is induced with ischemia and is cardioprotective. Overexpression of other HSPs also is protective against cardiac injury. Recently, we observed that 17beta-estradiol increases levels of HSPs in male rat cardiac myocytes. We hypothesized that there were gender differences in HSP72 expression in the heart secondary to estrogen. To test this hypothesis, we examined cardiac levels of HSP72 by ELISA in male and female Sprague-Dawley rats. In addition, three other HSPs were assessed by Western blot (HSP27, HSP60, and HSP90). To determine whether estrogen status affected HSP72 expression in other muscles or tissues, two other muscle tissues, slow twitch muscle (soleus muscle) and fast twitch muscle (gastrocnemius muscle), were studied as well as two other organs, the kidney and liver. Because HSP72 is cardioprotective, and females are known to have less cardiovascular disease premenopause, the effects of ovariectomy were examined. We report that female Sprague-Dawley rat hearts have twice as much HSP72 as male hearts. Ovariectomy reduced the level of HSP72 in female hearts, and this could be prevented by estrogen replacement therapy. These data show that the expression of cardiac HSP72 is greater in female rats than in male rats, due to upregulation by estrogen.

Hormone replacement therapy and the risk of incident congestive heart failure: the Cardiovascular Health Study

BACKGROUND

The development of congestive heart failure (CHF) in older persons is related to a variety of mechanisms. Hormone replacement therapy (HRT) affects several of the pathways that may be important in the development of CHF. We hypothesized that HRT would be associated with a decreased risk of incident CHF.

METHODS

Using Cox proportional-hazards regression, we assessed the risk of incident CHF (n = 304) associated with time-dependent past and current use of HRT compared to never use. The Cardiovascular Health Study is a prospective cohort study of community-dwelling adults aged 65 years and older. This analysis included female participants without a history of CHF at baseline (n = 3223).

RESULTS

At baseline, 62% were never users, 26% were past users, and 12% were current users of HRT. Compared with never users, the multivariable relative risk (RR) of CHF was 1.01 (95% confidence interval [95% CI] 0.76,1.34) for past users and 1.34 (0.93,1.94) for current users. Results were similar among most treatment and clinical subgroups, except that the association of current HRT with CHF appeared to depend on body mass index (BMI) or osteoporosis status. The RR was 0.82 (0.43,1.60) for normal weight women, 1.65 (0.95,2.88) for overweight women, and 2.22 (1.06,4.67) for obese women (p = 0.01 for interaction). Similarly, the RR was 0.15 (0.04,0.65) for women with osteoporosis and 1.82 (1.25,2.65) for women without osteoporosis (p = 0.001 for interaction).

CONCLUSIONS

Overall, HRT was not associated with the risk of incident CHF, although BMI and osteoporosis appeared to modify the association of HRT with CHF. The risk of CHF was lower in patients with lower BMI or osteoporosis.

The role of anticytokine therapy in heart failure: recent lessons from preclinical and clinical trials?

In summary, over a decade of investigation has demonstrated the pathophysiologic importance of TNF in the development and progression of cardiac dilatation and heart failure. Although the signaling pathways that regulate the cardiac production of TNF have not yet been identified and the potential benefits of TNF expression to the heart are not understood, the benefits of anticytokine therapy in animal models is marked. Unfortunately, these salutary effects in the laboratory have not transitioned to the bedside. To accomplish the translational portion of the cytokine story, we must identify the point in time during the transition from compensated to decompensated heart failure in which TNF is expressed. In addition, we must better understand the role that other down-stream and non-TNF-dependent cytokines play in the development of heart failure. Not all patients are the same; therefore, we must pursue clinical trials that will allow us to elucidate the optimal degree of TNF inhibition, identify the patients who are most likely to respond to TNF inhibition, and determine what the true, long-term effects of TNF inhibition may be. Finally, we must recognize that inflammatory activities can exist in tissues and organs in the absence of TNF. Thus, anticytokine strategies alone might not be effective in ameliorating the signs and symptoms of heart failure. It is hoped that the failure of recent studies to demonstrate salutary benefits in patients with class II to IV heart failure will not diminish enthusiasm for the long-term potential of anticytokine therapy.

Management of congestive heart failure: a gender gap may still exist. Observations from a contemporary cohort

BACKGROUND

Unlike other cardiovascular diseases the incidence and prevalence of congestive heart failure (CHF) continues to increase. While gender differences in coronary artery disease have been well described, to date, there has been a relative paucity of similar data in patients with CHF. We conducted a pilot study to evaluate the profile and management of patients with CHF at a tertiary care centre to determine if a gender difference exists.

METHODS

A chart review was performed at a tertiary care centre on consecutive patients admitted with a primary diagnosis of CHF between June 1997 and 1998. Co-morbidity, diagnostic investigations, and management of CHF were recorded. Comparisons between male and female patients were conducted.

RESULTS

One hundred and forty five patients were reviewed. There were 80 male (M) and 65 female (F) patients of similar age [71.6 vs. 71.3 (M vs. F), p = NS]. Male patients were more likely to have had a previous myocardial infarction (66% vs. 35%, p < 0.01) and revascularization (41% vs. 20%, p < 0.05), and had worse left ventricular ejection fraction (LVEF) than women, [median LVEF 3 vs. 2 (M vs. F), p < 0.01]. Male patients were more likely to have a non-invasive assessment of left ventricular (LV) function [85% vs. 69%, (M vs. F), p < 0.05]. A logistic regression analysis suggests that amongst those without coronary disease, males were more likely to receive non-invasive testing. There were no differences in the use of prescribed medications, in this cohort.

CONCLUSIONS

This pilot study demonstrated that there seem to be important gender differences in the profile and management of patients with CHF. Importantly women were less likely to have an evaluation of LV function. As assessment of LV function has significant implications on patient management, this data justifies the need for larger studies to assess gender differences in CHF profile and treatment.

Acute haemodynamic effects of oestrogen administration in male patients with chronic heart failure

BACKGROUND

Although there are many studies concerning the effects of long-term oestrogen administration on systemic haemodynamics in postmenopausal women, the effects of oestrogen in patients with chronic heart failure are not defined.

AIM

The goal of this study was to evaluate the acute haemodynamic effects of oestrogen in male patients with chronic heart failure.

METHODS AND RESULTS

We studied 15 men with advanced heart failure (NYHA II-IV, EF < 35%). A Swan-Ganz thermodilution catheter was advanced in their pulmonary artery and central haemodynamics were assessed at baseline, after placebo administration, and following 0.625 and 1.25 mg of oestrogen infusion. Simultaneously, all patients underwent limb plethysmography. Analysis of variance with repeated measures was used to compare the sequential measurements. Following oestrogen administration, right atrial, pulmonary artery and pulmonary capillary wedge pressures, as well as systemic, pulmonary and forearm vascular resistance were decreased; cardiac output, cardiac index, stroke volume, stroke volume index, stroke work index and forearm blood flow were increased.

CONCLUSIONS

In male patients with chronic heart failure, acute oestrogen administration improves the indices of cardiac systolic performance and decreases pulmonary and systemic vascular resistance. These findings imply a beneficial effect of oestrogen in selected patients with chronic heart failure.

Heart failure and its impact on older women's lives

AIM OF THE STUDY

This phenomenological study sought to examine and describe the experience of living with heart failure (HF) from the perspective of five women who live with Stage II HF.

BACKGROUND

Research has shown that women are affected by HF differently than men, having different risk factors, a higher increase in mortality per decade, and longer survival after diagnosis. Women have also been greatly under-represented in studies of HF. A search of the literature revealed only one Swedish study examining the overall impact of HF on women's conceptions of their own lives.

RESEARCH METHODS

Four 1-hour semi-structured interviews were held with each participant. Colaizzi's steps were used to analyse the verbatim transcripts of the interviews, drawing meanings from the participants' words.

FINDINGS

Four main themes emerged from the data: 'Acknowledging Losses in Their Lives', 'Accepting the Losses', 'Changing Their Lives' and 'Deepening Relationships'. Additionally, each theme contained several subthemes.

CONCLUSION

Findings from this study indicate that no aspect of women's lives escapes the impact of HF. It causes immense losses in many areas of life, and requires tremendous changes in many aspects of daily living. Yet, drawing on inner resources of great strength and courage, these women learn to find contentment in their lives. They discover ways to create productive lives and deeply meaningful relationships, within the boundaries imposed by HF.

Clinical profile of chronic heart failure in elderly women

The pathogenesis, clinical course, and treatment of chronic heart failure (HF) are different in elderly women from those of patients recruited in the landmark trials of chronic HF. Patients included in these landmark trials were predominantly men whose age was 10-15 years younger than the average age of patients with chronic HF in the United States. Diastolic dysfunction resulting in impaired left ventricular (LV) filling is the preponderant LV functional alteration that leads to chronic HF in elderly women. Gender differences in the LV remodeling process that accompanies chronic cardiac pressure are likely to be responsible for the preponderance of LV diastolic dysfunction over systolic dysfunction in elderly women. In response to chronic pressure overload, the LV wall becomes thicker in women than in men. Consequently, in response to chronic pressure overload, women are able to normalize LV wall stress and preserve LV systolic function to a greater extent than men. However, impaired LV filling is an undesirable consequence of the greater increase in LV wall thickness in women. Thus, clinical observations and therapeutic guidelines derived from data collected in the landmark trials of chronic HF may not apply to elderly women with chronic HF. In view of the lack of evidence-based information needed to guide the management of elderly women with chronic HF, special attention should be given to include a substantial number of elderly women in future therapeutic trials recruiting patients with chronic HF.

Postmenopausal oestrogen replacement therapy and atherosclerosis: can current compounds provide cardiovascular protection?

The natural oestrogen, 17 beta-oestradiol, has been implicated in protection from atherosclerosis, a chronic systemic vascular disease with an inflammatory component accounting for the majority of morbidity and mortality in Western countries. Despite the protective effects of 17 beta-oestradiol in premenopausal women and experimental evidence demonstrating inhibitory effects of oestrogen on atherosclerosis progression, it is currently unclear whether hormone replacement therapy can affect cardiovascular morbidity and mortality in postmenopausal women. The recent advances in understanding the mechanisms of oestrogen action demonstrated roles for different oestrogen receptors and oestrogen metabolites in the pathogenesis of vascular injury and endothelial cell dysfunction. However, their respective role in the process of atherogenesis remains yet to be elucidated. Moreover, the availability of novel drugs with tissue- and/or receptor-specific actions will help to understand the role of oestrogen in cardiovascular diseases. Several ongoing large-scale clinical trials using opposed or unopposed replacement therapy with natural or synthetic oestrogens, or selective oestrogen receptor modulators (SERMs) will resolve the question whether the drugs currently available have therapeutic potential to interfere with the progression of atherosclerosis and its complications.

The heart as a target for oestrogens

Observational studies have consistently shown a markedly decreased risk of cardiovascular disease in postmenopausal women when treated with oestrogens. This review discusses plausible mechanisms for the physiological effects of oestrogens in healthy and diseased hearts. Oestrogens have well-documented effects on blood lipids and the regulators of the cardiovascular system, which should reduce risk. In addition, the heart is a primary target for oestrogens with functional oestrogen receptors in the coronary vasculature and on cardiac myocytes and fibroblasts. Rapid oestrogen effects include vasodilatation and anti-arrhythmic effects by actions on ion channels, and some of these effects may be pharmacological rather than physiological. Longer term responses to physiological levels of oestrogen include an increased expression of nitric oxide synthase in myocytes and endothelial cells as well as proinflammatory and pro-arrhythmic effects. Oestrogens induce growth of non-proliferating fibroblasts but inhibit the replication of proliferating fibroblasts. In contrast to the observational studies, two randomised, controlled studies of oestrogen and progestins in postmenopausal women with coronary heart disease have now shown increased coronary events, especially in the first year of study, and no change in the progression of coronary atherosclerosis. Further studies of the complex effects of oestrogens on healthy and diseased animal models are essential. Large clinical trials of the newer selective oestrogen receptor modulators to lower cardiovascular risk in both males and females should be considered as a priority.