Subgroup interactions in the Heart and Estrogen/Progestin Replacement Study: lessons learned

"Cardiac glycosides"-quo vaditis?-past, present, and future?

Up to date, digitalis glycosides, also known as "cardiac glycosides", are inhibitors of the Na+/K+-ATPase. They have a long-standing history as drugs used in patients suffering from heart failure and atrial fibrillation despite their well-known narrow therapeutic range and the intensive discussions on their raison d'être for these indications. This article will review the history and key findings in basic and clinical research as well as potentially overseen pros and cons of these drugs.

Optimization of Drug Therapy for Heart Failure With Reduced Ejection Fraction Based on Gender

PURPOSE OF REVIEW

Over the last decades, several classes of drugs have been introduced for the treatment of patients with heart failure with reduced ejection fraction (HFrEF). Their use has been supported by randomized controlled trials that have demonstrated improved patient outcomes. However, these trials enrolled a small number of female patients and sometimes have reported gender-related differences regarding the efficacy of the treatments. The aim of this review is to revise the available data about the influence of gender on the optimal treatment and drug dose in patients with HFrEF.

RECENT FINDINGS

Several gender-related differences in terms of pharmacokinetic and pharmacodynamic characteristics of the drugs have been described. These characteristics could be responsible for a different response and tolerability in men and women also when current recommended treatment of HFrEF is considered. Some studies have shown that, in women, lower doses of beta-blockers and inhibitors of renin angiotensin aldosterone system could be equally effective than higher doses in men, whereas sacubitril/valsartan could exert its favorable effect at greater values of left ventricular ejection fraction. Although there is evidence about differences in the response to treatment of HFrEF in men and women, this has not been sufficient for differentiating current recommended therapy. Further studies should better clarify if the treatment of HFrEF should be based also on the patients' gender.

Sex and Gender Aspects in Vascular Ageing - Focus on Epidemiology, Pathophysiology, and Outcomes

Sex and gender are important modifiers of cardiovascular system physiology, pathophysiology, and disease development. The atherosclerosis process, together with the progressive loss of arterial elasticity with age, is a major factor influencing the development of overt cardiovascular, renal, and cerebrovascular disease. While differences between women and men in epidemiology and pathophysiology of vascular ageing are increasingly reported, sex-disaggregated data are still scarcely available for prospective studies. A better knowledge of sex differences in physiological ageing as well as in disease-related changes in vascular ageing trajectories is crucial to avoid misdiagnosis and mistreatment. This review presents key concepts and knowledge gaps identified in vascular ageing due to gonadal function, vascular physiology, pathophysiology, psychosocial factors, pregnancy, and prognostic relevance. Gender roles determine the effectiveness of any cardiovascular preventive strategy and acceptance for non-invasive or invasive diagnostics and therapeutics. Gender differences in health behaviour, also due to sociocultural norms conditioned by society, contribute to behaviours that may lead to premature arterial vascular ageing. These include differences in risk behaviours like smoking, diet, exercise, and in stress, but also conditions such as housing, noise pollution, poverty, disability, and any kind of stigmatisation. The VascAgeNet Gender Expert Group aims to advance the use of non-invasive vascular ageing measures in routine clinical settings by providing facts to fill in the gaps concerning sex and gender differences at each step of this process, and to search for solutions.

Association of digoxin therapy with case fatality rate in acute pulmonary embolism

OBJECTIVE

Despite wide usage of digoxin for various diseases in cardiology practice, its benefit is controversial and moreover it had been associated with unfavorable outcomes in some previous studies. The aim of this present study was to demonstrate whether digoxin usage was related with worse outcomes or not in patients with acute pulmonary embolisms.

METHODS

A total number of 1215 patients retrospectively enrolled for the study. Basic demographic features, pulmonary embolism severity index (PESI) scores, laboratory parameters and medications of patients who had been diagnosed with acute pulmonary embolism were recorded. Short (30 days) and long-term mortality were reported as the clinical outcomes.

RESULTS

Total mortality was 15.4% in the study population and 78 of these subjects died within the first 30 days. The frequency of digoxin treatment was 8% and most of these patients were prior users. According to the binary logistic regression analyses the PESI score, right ventricle (RV) diastolic diameter, systolic pulmonary arterial pressure (sPAP), brain natriuretic peptide (BNP), troponin and digoxin therapy (odds ratio, OR: 2.82 95% confidence interval, CI: 1.39-8.31, P = 0.03) were found as independent predictors of short-term mortality. Beside these findings; sPAP, PESI score, RV diastolic diameter and digoxin therapy (hazard ratio, HR: 2.11 95%CI: 1.22-7.31, P = 0.03) were determined as independent predictors of long-term mortality in Cox regression analyses. In subgroup analysis, we determined significantly greater increase in short-term mortality with use of digoxin among patients who had chronic renal disease, among patients under thrombolytic therapy and under high dosage of digoxin therapy and among female patients.

CONCLUSION

Digoxin has been used extensively for decades in the treatment of heart failure and arrhythmias despite some controversies over its benefit. For the first time in the literature, we have demonstrated independent association of digoxin therapy with short-term and long-term mortality in patients with acute pulmonary embolism.

No improvement in the reporting of clinical trial subgroup effects in high-impact general medical journals

BACKGROUND

When subgroup analyses are not correctly analyzed and reported, incorrect conclusions may be drawn, and inappropriate treatments provided. Despite the increased recognition of the importance of subgroup analysis, little information exists regarding the prevalence, appropriateness, and study characteristics that influence subgroup analysis. The objective of this study is to determine (1) if the use of subgroup analyses and multivariable risk indices has increased, (2) whether statistical methodology has improved over time, and (3) which study characteristics predict subgroup analysis.

METHODS

We randomly selected randomized controlled trials (RCTs) from five high-impact general medical journals during three time periods. Data from these articles were abstracted in duplicate using standard forms and a standard protocol. Subgroup analysis was defined as reporting any subgroup effect. Appropriate methods for subgroup analysis included a formal test for heterogeneity or interaction across treatment-by-covariate groups. We used logistic regression to determine the variables significantly associated with any subgroup analysis or, among RCTs reporting subgroup analyses, using appropriate methodology.

RESULTS

The final sample of 416 articles reported 437 RCTs, of which 270 (62 %) reported subgroup analysis. Among these, 185 (69 %) used appropriate methods to conduct such analyses. Subgroup analysis was reported in 62, 55, and 67 % of the articles from 2007, 2010, and 2013, respectively. The percentage using appropriate methods decreased over the three time points from 77 % in 2007 to 63 % in 2013 (p < 0.05). Significant predictors of reporting subgroup analysis included industry funding (OR 1.94 (95 % CI 1.17, 3.21)), sample size (OR 1.98 per quintile (1.64, 2.40), and a significant primary outcome (OR 0.55 (0.33, 0.92)). The use of appropriate methods to conduct subgroup analysis decreased by year (OR 0.88 (0.76, 1.00)) and was less common with industry funding (OR 0.35 (0.18, 0.70)). Only 33 (18 %) of the RCTs examined subgroup effects using a multivariable risk index.

CONCLUSIONS

While we found no significant increase in the reporting of subgroup analysis over time, our results show a significant decrease in the reporting of subgroup analyses using appropriate methods during recent years. Industry-sponsored trials may more commonly report subgroup analyses, but without utilizing appropriate methods. Suboptimal reporting of subgroup effects may impact optimal physician-patient decision-making.

Menopausal hormone therapy and cardiovascular disease risk: utility of biomarkers and clinical factors for risk stratification

BACKGROUND

Menopausal hormone therapy (HT) continues to have a clinical role in symptom management, but identifying women for whom benefits will outweigh the risks remains a challenge. Although hormone therapy (HT) is the most effective strategy for ameliorating vasomotor and other symptoms, randomized clinical trials show an unfavorable balance of benefits and risks for many women. However, closer examination of data from these trials suggests that it may be possible to classify women as better or worse candidates for HT by using individual risk stratification.

CONTENT

Data from 2 landmark trials-the Women's Health Initiative (WHI) and the Heart and Estrogen/progestin Replacement Study (HERS)-suggest an important role for clinical characteristics, serum biomarkers, genomic markers, and gene-environment interactions in developing a personalized approach to the prediction of risk for cardiovascular disease (CVD) events for women while on HT. The available data suggest several characteristics of women who are optimal candidates for HT use: younger age (<60 years), recent onset of menopause (<10 years), favorable lipid profile (LDL cholesterol <130 mg/dL or LDL/HDL cholesterol ratio <2.5), absence of metabolic syndrome, and absence of factor V Leiden genotype. The identification of other characteristics is an area of active investigation. In addition, women at high risk for venous thromboembolism should avoid systemic HT or choose a transdermal rather than oral delivery route.

SUMMARY

Personalized medicine-i.e., the use of the specific biological profile of an individual to guide the choice of treatment-is highly relevant for clinical decision-making regarding HT and offers promise for improved treatment efficacy and safety.

Lipoprotein(a), cardiovascular disease, and contemporary management

Elevated lipoprotein(a) (Lp[a]) is a causal genetic risk factor for cardiovascular disease. To determine if current evidence supports both screening and treatment for elevated Lp(a) in high-risk patients, an English-language search of PubMed and MEDLINE was conducted. In population studies, there is a continuous association between Lp(a) concentrations and cardiovascular risk, with synergistic effects when low-density lipoprotein (LDL) is also elevated. Candidates for Lp(a) screening include patients with a personal or family history of premature cardiovascular disease, familial hypercholesterolemia, recurrent cardiovascular events, or inadequate LDL cholesterol (LDL-C) responses to statins. Given the comparative strength of clinical evidence, reducing LDL-C to the lowest attainable value with a high-potency statin should be the primary focus of lipid-modifying therapies. If the Lp(a) level is 30 mg/dL or higher in a patient who has the aforementioned characteristics plus residual LDL-C elevations (≥70-100 mg/dL) despite maximum-potency statins or combination statin therapy, the clinician may consider adding niacin (up to 2 g/d). If, after these interventions, the patient has progressive coronary heart disease (CHD) or LDL-C levels of 160-200 mg/dL or higher, LDL apheresis should be contemplated. Although Lp(a) is a major causal risk factor for CHD, no currently available controlled studies have suggested that lowering it through either pharmacotherapy or LDL apheresis specifically and significantly reduces coronary risk. Further research is needed to (1) optimize management in order to reduce CHD risk associated with elevated Lp(a) and (2) determine what other intermediate- or high-risk groups might benefit from Lp(a) screening.

Estrogen therapy, independent of timing, improves cardiac structure and function in oophorectomized mRen2.Lewis rats

OBJECTIVE

mRen2.Lewis rats exhibit exacerbated increases in blood pressure, left ventricular (LV) remodeling, and diastolic impairment after the loss of estrogens. In this same model, depletion of estrogens has marked effects on the cardiac biopterin profile concomitant with suppressed nitric oxide release. With respect to the establishment of overt systolic hypertension after oophorectomy (OVX), we assessed the effects of timing long-term 17β-estradiol (E2) therapy on myocardial function, myocardial structure, and the cardiac nitric oxide system.

METHODS

OVX (n = 24) or sham operation (Sham; n = 13) was performed in 4-week-old female mRen2.Lewis rats. After randomization, OVX rats received E2 immediately (OVX + E2-early; n = 7), E2 at 11 weeks of age (OVX + E2-late; n = 8), or no E2 at all (OVX; n = 9).

RESULTS

E2-early was associated with lower body weight, less hypertension-related cardiac remodeling, and decreased LV filling pressure compared with OVX rats without E2 supplementation. E2-late similarly attenuated the adverse effects of ovarian hormone loss on tissue Doppler-derived LV filling pressures and perivascular fibrosis, and significantly improved myocardial relaxation or mitral annular velocity (e'). Early and late exposures to E2 decreased dihydrobiopterin, but only E2-late yielded significant increases in cardiac nitrite concentrations.

CONCLUSIONS

Although there are some similarities between E2-early and E2-late treatments in relation to preservation of diastolic function and cardiac structure after OVX, the lusitropic potential of E2 is most consistent with late supplementation. The cardioprotective effects of E2-late are independent of blood pressure and may have occurred through regulation of cardiac biopterins and nitric oxide production.

Vascular disease in diabetic women: Why do they miss the female protection?

Gender plays a pivotal role in the onset as well as in the progression of the cardiovascular disease with a higher morbidity and mortality being detected in men with respect to women. Type 2 Diabetes Mellitus (T2DM) may reduce gender-related differences in the prevalence of cardiovascular disease by fading the vascular protective effects afforded by estrogen in females. This article will discuss the role of sex and sex hormones on the incidence and mechanisms involved in vascular dysfunction associated to T2DM, which might explain why women with T2DM lack the vascular protection.

Activation of GPR30 attenuates diastolic dysfunction and left ventricle remodelling in oophorectomized mRen2.Lewis rats

AIMS

GPR30 is a novel oestrogen receptor expressed in various tissues, including the heart. We determined the role of GPR30 in the maintenance of left ventricular (LV) structure and diastolic function after the surgical loss of ovarian hormones in the female mRen2.Lewis rat, a model emulating the cardiac phenotype of the post-menopausal woman.

METHODS AND RESULTS

Bilateral oophorectomy (OVX) or sham surgery was performed in study rats; the selective GPR30 agonist, G-1 (50 µg/kg/day), or vehicle was given subcutaneously to OVX rats from 13-15 weeks of age. Similar to the cardiac phenotype of sham rats, G-1 preserved diastolic function and structure relative to vehicle-treated OVX littermates independent of changes in blood pressure. G-1 limited the OVX-induced increase in LV filling pressure, LV mass, wall thickness, interstitial collagen deposition, atrial natriuretic factor and brain natriuretic peptide mRNA levels, and cardiac NAD(P)H oxidase 4 (NOX4) expression. In vitro studies showed that G-1 inhibited angiotensin II-induced hypertrophy in H9c2 cardiomyocytes, evidenced by reductions in cell size, protein content per cell, and atrial natriuretic factor mRNA levels. The GPR30 antagonist, G15, inhibited the protective effects of both oestradiol and G-1 on this hypertrophy.

CONCLUSION

These data show that the GPR30 agonist G-1 mitigates the adverse effects of oestrogen loss on LV remodelling and the development of diastolic dysfunction in the study rats. This expands our knowledge of the sex-specific mechanisms underlying diastolic dysfunction and provides a potential therapeutic target for reducing the progression of this cardiovascular disease process in post-menopausal women.

Carotid endarterectomy benefits patients with CKD and symptomatic high-grade stenosis

Endarterectomy is generally recommended for symptomatic high-grade (70 to 99%) stenosis of the internal carotid artery, but whether this procedure is beneficial among patients with chronic kidney disease (CKD) is unknown. In this re-analysis of data from the North American Symptomatic Carotid Endarterectomy Trial, we included patients with symptomatic stenosis and either stage 3 CKD (n = 524) or preserved kidney function (n = 966; estimated GFR > or = 60). For medically treated patients with high-grade stenosis, risk for ipsilateral stroke at 2 yr was significantly higher in patients with CKD than in those with preserved renal function (31.6 versus 19.3%; P = 0.042); carotid endarterectomy significantly reduced this risk by 82 and 51%, respectively. To prevent one ipsilateral stroke, the number needed to treat by endarterectomy was four for patients with CKD and 10 for patients with preserved renal function. Compared with patients with preserved renal function, those with CKD had similar rates of perioperative stroke and death but higher rates of cardiac events. In conclusion, patients with stage 3 CKD and symptomatic high-grade carotid stenosis gain a large benefit in stroke risk reduction after endarterectomy.

Postmenopausal hormone therapy and the risk of cardiovascular disease

BACKGROUND

Risks and benefits of postmenopausal hormone therapy remain highly controversial. After publication of the Women's Health Initiative hormone trials and several other major trials, the American Heart Association designated postmenopausal hormone therapy as 'Class III', if initiated for the purpose of cardiovascular disease prevention. Subsequent post hoc analyses of the Women's Health Initiative data have renewed enthusiasm for hormone therapy among younger postmenopausal women.

OBJECTIVE

To review data from randomized clinical trials that have assessed cardiovascular outcomes of hormone therapy including coronary heart disease, stroke, peripheral arterial disease, and venous thromboembolism.

METHODS

The review focuses on cardiovascular effects of hormone therapy only and does not attempt to integrate potential risks and benefits related to symptoms, cancer, osteoporosis or other noncardiovascular effects of postmenopausal hormone therapy. The literature search included original trial publications, post hoc analyses, and aggregate data from meta-analyses published in English and accessible to the author in full-text format for detailed analysis.

RESULTS/CONCLUSION

Risks of hormone therapy seem to predominate among older postmenopausal women. Data among younger women close to menopause are insufficient to recommend such therapy for cardiovascular disease prevention.

Does hormone replacement therapy affect the use of prescription medicines in postmenopausal women: experience from the Estonian Postmenopausal Hormone Therapy Trial [ISRCTN35338757]

OBJECTIVE

To determine how postmenopausal hormone therapy (HRT) is related to the use of other prescription medication.

DESIGN

Follow up of a randomised controlled trial with a blind subtrial of hormone therapy versus placebo and a nonblind subtrial of open label hormone therapy versus nontreatment.

POPULATION

A total of 1823 postmenopausal women aged 50-64 at the time of sampling participated in the trial from 1999 to 2004.

METHODS

Use of prescription medication was identified by records in the central computerised database of the Estonian Health Insurance Fund.

MAIN OUTCOME MEASURES

The use of 21 classes of prescription medication was compared in the hormone therapy arms and placebo or nontreatment trial arms. The influence of women's socio-economic characteristics on the intensity of concomitant medication use was also examined.

RESULTS

The proportion of women using any prescription medication besides hormone therapy did not differ between the arms. However, the type of prescribed drugs varied between the arms. After combining data from both hormone therapy arms, for women using HRT the combined hazard ratio was 1.26 (95% CI: 1.05-1.53) for the use of calcium channel blockers, 1.48 (95% CI: 1.10-1.99) for local vaginal treatment, 0.70 (95% CI: 0.50-0.99) for hypnotics and sedatives and 0.77 (95% CI: 0.60-0.99) for selective serotonin reuptake inhibitors (SSRIs). Women who were older, who had a higher body mass index, who were unemployed and who lived outside the capital used more prescription drugs in comparison with others.

CONCLUSIONS

Hormone therapy did not increase the overall use of prescription medication other than hormone therapy, but the types of drugs used in hormone therapy and nontherapy arms varied, with increased use of calcium channel blockers for hypertension and local vaginal treatments for vaginal candidiasis and decreased use of hypnotics, sedatives and SSRIs in the HRT arms.

Case-only analysis of treatment-covariate interactions in clinical trials

Differential effectiveness of treatments across subgroups defined by pretreatment variables are of increasing interest, particularly in the expanding research field of pharmacogenomics. When the pretreatment variable is difficult to obtain or expensive to measure, but can be assessed at the end of the study using stored samples, nested case-control and case-cohort methods can be used to reduce costs in large efficacy trials with rare outcomes. Case-only methods are even more efficient, and reliable under a range of circumstances.

Effects of low-dose continuous combined hormone replacement therapy on glucose homeostasis and markers of cardiovascular risk in women with type 2 diabetes

BACKGROUND

Low-dose hormone replacement therapy (HRT) has attracted interest for the treatment of postmenopausal symptoms in diabetes because of concerns about increased risk of coronary heart disease (CHD) and stroke with conventional HRT containing conjugated equine oestrogens (CEEs) and medroxyprogesterone acetate (MPA).

OBJECTIVES

We assessed the effects on glucose homeostasis and cardiovascular risk factors of continuous oral 17beta oestradiol (1 mg) and norethisterone (0.5 mg) in postmenopausal women with type 2 diabetes.

DESIGN

Double-blind, randomized placebo-controlled trial.

ASSESSMENTS

Hyperinsulinaemic isoglycaemic clamp and cardiovascular risk factors were assessed before and after 3 months of treatment.

RESULTS

Twenty-eight women completed the study. HRT decreased fasting glucose compared with placebo [-9.4% with HRT vs.+2.3% for placebo, 95% confidence interval (CI) -23.2 to -0.3] and total cholesterol (-13.7 vs.+1.0%, 95% CI -22.4 to -3.1%) No significant effect was seen on metabolic clearance rate of glucose, glycated haemoglobin (HbA1c), triglycerides, high density lipoprotein (HDL)-cholesterol or C-reactive protein (CRP).

CONCLUSIONS

In women with type 2 diabetes, low-dose HRT decreased fasting glucose and total cholesterol without detectable adverse effects on glucose clearance, triglycerides and CRP as reported with conventional HRT.

Hormone replacement therapy and risk of acute myocardial infarction : a review of the literature

Many animal studies and studies on intermediate clinical endpoints have shown hormone replacement therapy (HRT) to be associated with both favourable and unfavourable cardiovascular effects. We reviewed the literature regarding HRT and the distinct endpoint of acute myocardial infarction (AMI) in peri- and postmenopausal women. Searches of the MEDLINE and EMBASE databases were conducted. Fifty papers were identified as eligible for inclusion: eight randomised controlled trials, 18 cohort studies, 23 case-control studies and one case-control and cohort study. The single large primary prevention randomised controlled trial on HRT and the risk of AMI in generally healthy women (Women's Health Initiative trial) reported a small yet significantly increased risk of AMI in postmenopausal women receiving combined HRT. This contrasts with a large number of observational studies that suggested a protective effect, although in many of these studies the results were not statistically significant. Inconclusive evidence on the effect of duration of use does not support the notion that a possible protective association is causal. Detection bias and residual confounding are alternative explanations for the associations observed in the randomised controlled trial and observational studies. No studies on groups of women with existing cardiovascular disease or with diabetes mellitus, including the only large secondary prevention trial (Heart and Estrogen/Progestin Replacement Study), reported a significant change in AMI risk between HRT users and non-users. There is insufficient evidence to suggest that HRT is associated with a change in the risk of AMI in the majority of women. However, certain subgroups of women with specific genetic polymorphisms may be more susceptible to a change in the risk of AMI with HRT use.

Treatment of hot flushes in breast and prostate cancer

Hot flushes, the most common health problem reported by menopausal-age women, can lead to significant morbidity and affect the social life, ability to work and sleep pattern of the sufferer. Women treated for breast cancer and men receiving androgen ablation for prostate cancer experience hot flushes that are more frequent, severe and longer lasting than those experienced by the general menopausal population. In women with breast cancer, hot flushes can result from chemotherapy-induced menopause, hormonal therapy, or ovarian suppression. In men with prostate cancer, hot flushes occur after surgical or medical castration. Hormone replacement therapy with oestrogen-based compounds has been a mainstay of treatment for hot flushes during the perimenopausal period. However, recent studies have shown that, in healthy menopausal women, hormone replacement therapy is associated with an increased risk of breast cancer, myocardial infarction, thrombo-embolic events and stroke. Thus, identifying nonhormonal agents that can control hot-flush symptoms is essential to the quality of life of a growing population of cancer survivors. The most promising agents act on the CNS and include selective serotonin reuptake inhibitors, as well as venlafaxine and gabapentin.

Coronary artery disease in women: a review on prevention, pathophysiology, diagnosis, and treatment

Despite numerous studies on women's cardiac health throughout the past decade, the number of female deaths caused by cardiovascular disease still rises and remains the leading cause of death in women in most areas of the world. Novel studies have demonstrated that cardiovascular disease, and more specifically coronary artery disease presentations in women, are different than those in men. In addition, pathology and pathophysiology of the disease present significant gender differences, which leads to difficulties concerning diagnosis, treatment and outcome of the female population. The reason for this disparity is all steps for female cardiovascular disease evaluation, treatment and prevention are not well elucidated; and an area for future research. This review brings together the most recent studies published in the field of coronary artery disease in women and points out new directions for future investigation on some of the important issues.

Postmenopausal hormone therapy and mammographic breast density

OBJECTIVE

The aim of this study was to evaluate the effects of different types of hormone replacement therapy (HRT) on mammographic density.

MATERIALS AND METHODS

In a prospective 1-year study, 103 postmenopausal women were randomized to receive tibolone 2.5 mg/die, continuous conjugated equine estrogens 0.625 mg/die plus medroxyprogesterone acetate (MPA) 5mg/die or placebo. Mammograms were performed at baseline and after 12 months of treatment. Mammographic density was quantified according to the Wolfe classification.

RESULTS

After 12 months of HRT 16 of the 35 patients (45.1%) receiving continuous combined hormonal therapy showed an increase of breast density change in the Wolfe classification. After treatment with tibolone, an up grading in breast density, according to Wolfe's classification, was found in 2 of the 43 patients (2.3%). No changes were recorded in the 25 patients of the control group. The difference between the group treated with continuous combined hormonal therapy and the control group was highly significant (p<0.001). The difference in breast density between patients in treatment with tibolone and the control group was not statistically significant (p=0.34).

DISCUSSION

Continuous combination HRT may be more commonly associated with an increase of mammography density than tibolone treatment.

Evaluation of a Sex-Based Difference in the Pharmacokinetics of Digoxin

STUDY OBJECTIVE

To determine whether a sex-based difference in digoxin pharmacokinetics exists in patients receiving long-term digoxin therapy for chronic heart failure or atrial fibrillation.

DESIGN

Single-center, retrospective review of medical records.

SETTING

University-based teaching hospital and outpatient clinic.

PATIENTS

Sixty-seven adults (32 men, 35 women) with chronic heart failure or atrial fibrillation who were receiving digoxin therapy.

MEASUREMENTS AND MAIN RESULTS

Serum digoxin concentrations and daily digoxin doses were obtained from patients' medical records. Daily doses were adjusted for patients' actual and ideal body weight and body mass index (BMI). The ratio between the serum digoxin concentration and each of the adjusted daily doses of digoxin was compared between men and women. The mean +/- SD serum digoxin concentration was 0.85 +/- 0.51 ng/ml for men compared with 1.02 +/- 0.51 ng/ml for women. Mean +/- SD unadjusted doses of digoxin were 0.180 +/- 0.063 and 0.164 +/- 0.059 mg/day for men and women, respectively; the difference was not statistically significant. Ratios of serum digoxin concentration to daily digoxin doses did not differ by sex when doses were estimated with actual or ideal weight. Only the ratio of the digoxin concentration to the BMI-adjusted dose was significantly different between men and women (0.14 +/- 0.09 and 0.19 +/- 0.11, respectively, p<0.05).

CONCLUSION

Sex-based differences in digoxin pharmacokinetics were absent when actual or ideal body weight was used. However, the ratio of serum digoxin concentration to daily digoxin dose adjusted for BMI differed by sex. Because digoxin is distributed to lean body mass, use of the BMI could have overadjusted body weight, leading to inaccurate pharmacokinetic assumptions and calculations. The pharmacokinetics of digoxin do not appear to differ by sex.

The impact of risk status, preexisting morbidity, and polypharmacy on treatment decisions concerning menopausal symptoms

Because each menopausal treatment has a unique benefit-risk profile, deciding whether menopausal hormone therapy (HT) or another menopausal treatment is appropriate for an individual requires assessing the risks and benefits of each treatment as well as determining the patient's risk factors, comorbidities, and current medications. Simple summary metrics for assessing net treatment effects on multiple outcomes, such as the Women's Health Initiative's (WHI) global index, are not necessarily generalizable beyond the study population in which they were derived. However, trial evidence can be translated to individual decisions by transforming relative risks into absolute risks. The validity of generalizing relative risks found in clinical trials to groups with differing baseline risks depends on the homogeneity of relative risks across various risk strata. Subgroup analyses from the major clinical studies of HT found its relative risks for cardiovascular disease, hip fracture, breast cancer, colorectal cancer, and ovarian cancer to be relatively uniform across strata defined by age, race/ethnicity, antecedent risk status, or prior disease. The number of significant subgroup findings in these studies tended to match the number expected by chance alone. However, data are limited for many subgroups, especially those with comorbidities. Strata defined by the concurrent use of drugs that can interact with HT are not expected to be homogeneous, yet data on drug interactions are limited. More data are needed about the effects of menopausal treatments in diverse populations, and more attention is needed to translate this evidence into clinical practice and to develop tools to support informed decision making.

Bridging advanced glycation end product, receptor for advanced glycation end product and nitric oxide with hormonal replacement/estrogen therapy in healthy versus diabetic postmenopausal women: A perspective

Cardiovascular diseases (CVD) are the most significant cause of death in postmenopausal women. The loss of estrogen biosynthesis with advanced age is suggested as one of the major causes of higher CVD in postmenopausal women. While some studies show beneficial effects of estrogen therapy (ET)/hormonal replacement therapy (HRT) in the cardiovascular system of healthy postmenopausal women, similar studies in diabetic counterparts contradict these findings. In particular, ET/HRT in diabetic postmenopausal women results in a seemingly detrimental effect on the cardiovascular system. In this review, the comparative role of estrogens is discussed in the context of CVD in both healthy and diabetic postmenopausal women in regard to the synthesis or expression of proinflammatory molecules like advanced glycation end products (AGEs), receptor for advanced glycation end products (RAGEs), inducible nitric oxide synthases (iNOS) and the anti-inflammatory endothelial nitric oxide synthases (eNOS). The interaction of AGE-RAGE signaling with molecular nitric oxide (NO) may determine the level of reactive oxygen species (ROS) and influence the overall redox status of the vascular microenvironment that may further determine the ultimate outcome of the effects of estrogens on the CVD in healthy versus diabetic women.

Female-specific aspects in the pharmacotherapy of chronic cardiovascular diseases

Differences in pharmacokinetics, pharmacodynamics, and physiology contribute to the phenomenon that women and men frequently respond differently to cardiovascular drugs. Hormonal influences, in addition, can play an important role: for example, the menstrual cycle, menopause, and pregnancy--as a result of fluctuations in concentrations of sexual steroids, and of changes in total body water--can be associated with gender-specific differences in the plasma levels of cardiovascular drugs. Clinical relevance accordingly results, especially for substances with a narrow therapeutic margin. This review treats the most important pharmacodynamic gender-relevant differences in this context, and surveys available evidence on the benefits of therapy of chronic cardiovascular diseases in women. On the whole, the study situation for women is appreciably less favourable than for men: owing to the fact that women are under-represented in most studies, and that few gender-specific analyses have been conducted.

The rise and fall of menopausal hormone therapy

Clinical trials show that hormone therapy (HT) is an effective treatment for vasomotor symptoms and vaginal dryness. HT improves other symptoms including sleep and quality of life in women who have menopause symptoms. In the Women's Health Initiative controlled clinical trials, both estrogen therapy (ET) and estrogen plus progestin therapy (EPT) reduced fracture risk, neither reduced the risk of heart disease, and both increased the risk of stroke, deep vein thrombosis, and dementia. EPT, but not ET, increased breast cancer risk and reduced colon cancer risk. Differences between EPT and ET may reflect chance, baseline differences between the EPT and ET cohorts, or a progestin effect. Studies of younger women and lower HT doses with intermediate endpoints are beginning.

Raloxifene lowers ischaemia susceptibility by increasing nitric oxide generation in the heart of ovariectomized rats in vivo

We studied the effects of a 2-week period of oral raloxifene therapy on the cardiac level of nitric oxide (NO) and on the susceptibility to angina in ovariectomized rats. Ovariectomy decreased the activity of Ca2+-dependent nitric oxide synthase (NOS) in the left ventricle, an effect restored by raloxifene (0.2-5 mg kg(-1) day(-1)) or 17beta-oestradiol (0.3 mg kg(-1) day(-1)). Ovariectomy led to a significant ST segment depression after the injection of (1) ornithine-vasopressin (0.5 IU kg(-1), i.v.) or (2) epinephrine (10 microg kg(-1), i.v.), followed 30 s later by phentolamine (15 mg kg(-1), i.v.); both effects were reversed by raloxifene or 17beta-oestradiol treatment. Inhibition of nitric oxide synthase (with NG-nitro-L-arginine methyl ester [L-NAME]; 5 mg kg(-1), s.c.) augmented the ST segment depression in the ovariectomized rat and abolished the anti-ischaemic effect of 17beta-oestradiol or raloxifene. Thus, an oestrogen deficiency down-regulates the cardiac constitutive nitric oxide synthase, which increases the susceptibility of the heart to ishaemia because both actions can be blocked by exogenous administration of the natural oestrogen 17beta-oestradiol or the selective oestrogen-receptor modulator (SERM) raloxifene. In the present in vivo system, raloxifene exerts oestrogen-agonist properties.

Hormone Therapy and Selective Estrogen Receptor Modulators for Prevention of Coronary Heart Disease in Postmenopausal Women

Coronary heart disease is the leading cause of morbidity and mortality in women older than the age of 50 in the United States today. Traditional cardiovascular risk factors (hyperlipidemia, glucose intolerance, and hypertension) are more clearly associated with significant cardiovascular risk after menopause. The increased incidence of cardiovascular events in postmenopausal women and the evidence that cardiovascular disease on average manifests a decade later in women compared with men suggests that estrogen deficiency may predispose women to a higher cardiovascular risk. Numerous biologic mechanisms have been proposed that relate use of hormone therapy (HT) to improved lipid profiles, insulin sensitivity, and vascular reactivity. Early observational trials in the last 2 decades showed a significant decrease in cardiovascular events. Recently published randomized clinical trial results, however, have led to uncertainty about the earlier established cardiovascular benefits of HT. To complicate issues further, alternative estrogenlike compounds, selective estrogen receptor modulators, are being introduced that appear to convey similar cardiovascular benefit and notably less cancer risk than HT. The newly released randomized trials on hormone and nonhormonal agents are reviewed.

Effect of hormone therapy on BP in normotensive and hypertensive postmenopausal women

High blood pressure (BP) ranks as the greatest risk factor for cardiovascular disease. The increased cardiovascular risk determined in recent interventional studies has led the health authorities in some countries to re-ignite the discussion about whether hypertension should be listed as a contraindication for hormone replacement therapy (HRT). We reviewed papers published since 1960 and listed in MEDLINE, EMBASE and Biosis, on studies that monitored the course of BP during HRT. We found that both primarily normotensive and hypertensive postmenopausal women actually run only a very low risk of BP increase during HRT, indeed, BP was often lowered. In one of our own studies 1397 hypertensive women with BP diastolic >95 mmHg received transdermal HRT regimens; BP was lowered by an average of 7 mmHg systolic and 9 mmHg diastolic. The results of the more recent 24-h ambulatory BP studies are particularly conclusive. At least 19 such studies have been performed, 13 placebo-controlled and 10 cross-over; 5 found no effect on BP and 14 studies demonstrated BP reductions. BP was lowered by treatment with transdermal estradiol in 11 of 13 studies and by oral estrogen in 4 of 11 studies. The effects were not consistent with regard to systolic or diastolic BP nor to action on day- and night-time BP. It cannot be ruled out that some women with a particular predisposition exhibit an abnormal reaction to the vasoactive effects of HRT, and there is a paucity of long-term data on risk populations, specifically on the progestogenic effects in patients with pre-existing arteriosclerotic lesions. In conclusion, the risk of developing hypertension during HRT is very low, but hormone therapy should always be appropriately indicated and during therapy BP should be checked regularly.

Effects of low-dose continuous combined HRT on vascular function in women with type 2 diabetes

BACKGROUND

Improvement in vascular endothelial function is widley cited as a beneficial effect of hormone replacement therapy (HRT). Women with type 2 diabetes (T2DM) are at increased cardiovascular risk and have impaired endothelial function. Any benefits of HRT on endothelial function in this group are of particular interest.

OBJECTIVES

We assessed effects on vascular function of oral 17beta oestradiol (1 mg) and norethisterone (0.5 mg) in postmenopausal women with T2DM.

DESIGN

Double-blind, randomised, placebo-controlled trial.

ASSESSMENTS

Twenty-eight women had pulse wave velocity (PWV) and adhesion molecules VCAM-1 and ICAM-1 assessed before and after three months' treatment. Twenty-four women also had gluteal fat biopsy for assessment of resistance vessel function (using wire myography).

RESULTS

HRT did not affect PWV, VCAM-1, ICAM-1 or carbachol response. Effects of L-NAME and indomethacin on carbachol sensitivity were similar in both groups.

CONCLUSIONS

This HRT preparation had no detectable effect on these measures of endothelial function in women with T2DM.

“Rise and fall” of hormone therapy in postmenopausal women with cardiovascular disease

Whereas observational data for postmenopausal women using hormone therapy (HT) have shown a protective effect against cardiovascular disease, prospective, randomized trials have demonstrated a harmful effect on the vascular system. This study describes the effects of HT on lipids, hemostatic parameters, inflammation, and the vascular wall. Reasons for the different results of observational and experimental studies of HT are postulated. The timing of hormonal supplementation seems crucial. Used chronically, HT has no harmful effects; however, first-time use of HT after a recent cardiovascular event results in an early increase in adverse cardiovascular events. In most observational studies, women started HT for postmenopausal symptoms, whereas in experimental studies, women started HT 10 to 20 years or longer after menopause. Cumulative evidence supports the hypothesis that HT has more effect in maintaining vascular health than in alleviating endothelial dysfunction. HT has not proven beneficial in the long term in women at risk of a cardiovascular event. The interval between menopause and the start of HT plays a crucial role in the effectiveness of HT in the vascular system.

Oral, more than transdermal, estrogen therapy improves lipids and lipoprotein(a) in postmenopausal women: a randomized, placebo-controlled study

OBJECTIVE

To assess the effects of low-dose oral and transdermal estrogen therapy on the lipid profile and lipoprotein(a) [Lp(a)] levels in healthy, postmenopausal women and to study the additional influence of gestodene administration.

DESIGN

In a multicenter, randomized, double-blind, placebo-controlled study, 152 healthy, hysterectomized, postmenopausal women received daily either placebo (n = 49), 50 microg transdermal 17beta-estradiol (tE2, n = 33), 1 mg oral 17beta-estradiol (oE2, n = 37), or 1 mg oE2 combined with 25 microg gestodene (oE2 + G, n = 33) for 13 cycles of 28 days, followed by 4 cycles of placebo in each group. Fasting serum concentrations of total, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol, triglycerides, and Lp(a) were measured at baseline and in cycles 4, 13, and 17.

RESULTS

In cycle 13, a significant mean percentage decrease from baseline was found in all treatment groups compared with placebo in total cholesterol (tE2, -4.7%; oE2, -6.9%; oE2 + G, -10.5%) and LDL cholesterol (tE2, -5.8%; oE2, -12.6%; oE2 + G, -13.6%). For both oral groups, the reductions were already significant in cycle 4. None of the treatment groups showed a significant change in HDL cholesterol or triglycerides. In cycle 13, Lp(a) was decreased compared with placebo in the oE2 group (-6.6%) and the oE2 + G group (-8.2%). After washout, all observed changes had returned to baseline level, except for the decreases in total and LDL cholesterol in the oE2 + G group.

CONCLUSIONS

Oral E2 and E2 + G, and to a lesser extent transdermal E2, decreased total and LDL cholesterol. Lp(a) was lowered only by the oral treatments.

Estrogen plus progestin and the risk of coronary heart disease

BACKGROUND

Recent randomized clinical trials have suggested that estrogen plus progestin does not confer cardiac protection and may increase the risk of coronary heart disease (CHD). In this report, we provide the final results with regard to estrogen plus progestin and CHD from the Women's Health Initiative (WHI).

METHODS

The WHI included a randomized primary-prevention trial of estrogen plus progestin in 16,608 postmenopausal women who were 50 to 79 years of age at base line. Participants were randomly assigned to receive conjugated equine estrogens (0.625 mg per day) plus medroxyprogesterone acetate (2.5 mg per day) or placebo. The primary efficacy outcome of the trial was CHD (nonfatal myocardial infarction or death due to CHD).

RESULTS

After a mean follow-up of 5.2 years (planned duration, 8.5 years), the data and safety monitoring board recommended terminating the estrogen-plus-progestin trial because the overall risks exceeded the benefits. Combined hormone therapy was associated with a hazard ratio for CHD of 1.24 (nominal 95 percent confidence interval, 1.00 to 1.54; 95 percent confidence interval after adjustment for sequential monitoring, 0.97 to 1.60). The elevation in risk was most apparent at one year (hazard ratio, 1.81 [95 percent confidence interval, 1.09 to 3.01]). Although higher base-line levels of low-density lipoprotein cholesterol were associated with an excess risk of CHD among women who received hormone therapy, higher base-line levels of C-reactive protein, other biomarkers, and other clinical characteristics did not significantly modify the treatment-related risk of CHD.

CONCLUSIONS

Estrogen plus progestin does not confer cardiac protection and may increase the risk of CHD among generally healthy postmenopausal women, especially during the first year after the initiation of hormone use. This treatment should not be prescribed for the prevention of cardiovascular disease.

Gender, hyperlipidemia, and coronary artery disease

The importance of statins for the prevention and treatment of coronary artery disease (CAD), the recent paradoxical effects of hormone replacement therapy on prevention of CAD, and the role of nontraditional risk factors in CAD in women are examined.

Sex-based differences in the effect of digoxin for the treatment of heart failure

BACKGROUND

The Digitalis Investigation Group trial reported that treatment with digoxin did not decrease overall mortality among patients with heart failure and depressed left ventricular systolic function, although it did reduce hospitalizations slightly. Even though the epidemiologic features, causes, and prognosis of heart failure vary between men and women, sex-based differences in the effect of digoxin were not evaluated.

METHODS

We conducted a post hoc subgroup analysis to assess whether there were sex-based differences in the effect of digoxin therapy among the 6800 patients in the Digitalis Investigation Group study. The presence of an interaction between sex and digoxin therapy with respect to the primary end point of death from any cause was evaluated with the use of Mantel-Haenszel tests of heterogeneity and a multivariable Cox proportional-hazards model, adjusted for demographic and clinical variables.

RESULTS

There was an absolute difference of 5.8 percent (95 percent confidence interval, 0.5 to 11.1) between men and women in the effect of digoxin on the rate of death from any cause (P=0.034 for the interaction). Specifically, women who were randomly assigned to digoxin had a higher rate of death than women who were randomly assigned to placebo (33.1 percent vs. 28.9 percent; absolute difference, 4.2 percent, 95 percent confidence interval, -0.5 to 8.8). In contrast, the rate of death was similar among men randomly assigned to digoxin and men randomly assigned to placebo (35.2 percent vs. 36.9 percent; absolute difference, -1.6 percent; 95 percent confidence interval, -4.2 to 1.0). In the multivariable analysis, digoxin was associated with a significantly higher risk of death among women (adjusted hazard ratio for the comparison with placebo, 1.23; 95 percent confidence interval, 1.02 to 1.47), but it had no significant effect among men (adjusted hazard ratio, 0.93; 95 percent confidence interval, 0.85 to 1.02; P=0.014 for the interaction).

CONCLUSIONS

The effect of digoxin therapy differs between men and women. Digoxin therapy is associated with an increased risk of death from any cause among women, but not men, with heart failure and depressed left ventricular systolic function.