Mechanisms of thrombosis related to hormone therapy

Multi-Modal Venous ThromboembolicProphylaxis Aids in Risk Reduction Following Splenectomy in Female and Male Mice

INTRODUCTION

Splenectomy (SPLN) is associated with elevated risk of venous thromboembolic (VTE) disease. Enoxaparin (ENX) is a low-molecular-weight heparin agent used in VTE chemoprophylaxis. Early aspirin administration ameliorates postSPLN platelet hyperaggregability in male mice. Previous literature has excluded female mice, citing potential effects of estrogen on platelet count and activation as a reason. We hypothesized that multimodal therapy using aspirin and ENX would mitigate postoperative platelet aggregability in mice across sexes.

METHODS

Murine models of SPLN included both male and female mice. Treatment groups included placebo gavage, sham laparotomy, SPLN alone, SPLN and aspirin, SPLN and ENX, and SPLN with aspirin and ENX (n = 5 per group). Chemoprophylaxis dosing was initiated before SPLN. Mice were euthanized on post-operative day (POD) 1 or 3; platelet counts were obtained and blood samples were analyzed via electrical impedance aggregometry.

RESULTS

Females on POD 3 following SPLN demonstrated increased platelet count compared to female mice with no treatment intervention. Male and female mice demonstrated increased adenosine diphosphate (ADP)-induced platelet aggregability on POD 3 following SPLN compared to the placebo group. Treatment with aspirin and ENX decreased this post-SPLN platelet hyperaggregability in both sexes. Females demonstrated significantly higher ADP-mediated platelet aggregability in placebo, SPLN, and SPLN with aspirin and ENX when compared to males of identical treatment groups on POD 3.

CONCLUSIONS

Platelet hyperaggregability following SPLN is mediated primarily by ADP in both males and females, but higher relative aggregability is demonstrated in females. Early administration of dual-agent VTE chemoprophylaxis utilizing aspirin and ENX mitigates this hyperaggregability and may aid in VTE risk reduction across sexes.

Thrombotic and Vascular Complications of Oral Contraceptives

The oral contraceptive pill is the most commonly used form of reversible contraception, as it has significantly grown in popularity in recent years. The 2 types of oral contraceptive pills are combination oral contraceptives, which contain estrogen and progesterone, and progestin-only pills. Both have failure rates of approximately 7.2-9% with typical use and are safe for most patients. However, several thrombotic and vascular complications have been found to be associated with the usage of oral contraceptive pills, most notably being an increase in blood pressure and thrombosis. Although these complications do not typically affect young, healthy females, they merit concern for patients with a history of hypertension or thrombosis or patients with preexisting risk factors for these conditions. Overall, progestin-only pills are the safer option regarding these complications. Additionally, a complete summary of the medical eligibility criteria for contraceptive use has been created and is regularly updated by the Centers for Disease Control and Prevention. This chart summarizes the recommendations for contraception use by patients with a variety of preexisting conditions or risk factors.

Impact of Continuous Estroprogestin Treatment on Circulating Microparticle Levels in Deep Endometriosis Patients

There has been increasing interest in the study of new pathogenic mechanisms in endometriosis (END), including the coagulation/fibrinolysis system and its link with inflammation and tissue remodeling. It has been suggested that END patients, especially with deep-infiltrating (DE) forms, could present a hypercoagulable state revealing higher levels of proinflammatory and procoagulant markers, such as total circulating microparticles (cMPs) and cMP-TF (tissue factor), released by cells in response to damage, activation, or apoptosis. However, no previous study has assessed the effect of END hormonal treatments on cMP and cMP-TF levels. Therefore, the aim of this study was to evaluate the impact of these treatments on cMP and cMP-TF levels in DE patients. Three groups were compared: DE patients receiving a continuous combined oral contraceptive regimen (CCOCR) (n = 41), DE patients without CCOCR (n = 45), and a control group (n = 43). cMP and cMP-TF levels were evaluated in platelet-free plasma. A significant decrease in the total cMP levels was found in the DE group with CCOCR versus the group without CCOCR, reflecting a higher chronic inflammatory status in DE patients that decreased with the treatment. cMP-TF levels were higher in DE patients receiving CCOCR versus those not receiving CCOCR, suggesting that treatments containing estrogens play a predominant role in suppressing the inhibitory pathway of TF.

Trends in research related to menopausal hormone therapy from 2000 to 2021: A bibliometric analysis

We conducted the present bibliometric analysis to explore menopausal hormone therapy (MHT)-related research trends between 2000 and 2021. The Web of Science database was systematically searched from 2000 to 2021 to retrieve MHT-related publications. Visualization mapping and keyword cluster graphs were utilized to illustrate the research topics and hotpots. We included 11,616 MHT-related publications for this bibliometric analysis. The results showed that (1) MHT-related research had a very slow increase in the past 22 years, and the trend fluctuated. Sum of times cited and average citations per item had the same trend: a sharp decline from 2002 to 2003, and a rapid increase from 2003 to 2006, reaching the peak in 2006, then following a downward trend. The average H-index was 57, peaking in 2001; (2) the USA, the League of European Research Universities, and Dr. JoAann Manson from Harvard University contributed the most; (3) Menopause: The Journal of The North American Menopause Society had the most significant number of MHT-related publications; (4) the research hotpots primarily focused on MHT for treating menopausal symptoms and the impact of MHT on women’s health. According to previous studies, MHT was the most effective treatment for managing vasomotor symptoms of menopause, but results from the clinical trials and observational studies regarding MHT adverse events remain inconsistent. Mechanisms are fundamental when clinical studies give conflicting results. Therefore, future studies should focus on adverse events and their mechanisms.

Serum levels of tissue factor pathway inhibitor: Potential association with Raynaud's phenomenon and telangiectasia in patients with systemic sclerosis

Vasculopathy is a critical step of systemic sclerosis (SSc) development, bridging between autoimmune inflammation and tissue fibrosis. Impaired coagulation system is a part of SSc vasculopathy, but the role of tissue factor pathway inhibitor (TFPI), a critical regulator of the extrinsic coagulation pathway, remained unknown. Therefore, we evaluated the clinical correlation of serum TFPI levels in SSc patients. Serum TFPI levels were comparable between SSc and control participants, but SSc patients with Raynaud's phenomenon and telangiectasia had significantly lower serum TFPI levels than those without. Importantly, there was a significant positive correlation between serum TFPI levels and protein S activity. These results support the critical role of impaired coagulation system in SSc.

Estrogen and thrombosis: A bench to bedside review

Estrogen, in the clinical setting is used primarily for contraception and hormone replacement therapy. It has been well established that estrogen increases the risk of both arterial and venous thrombosis. While estrogen is known to induce a prothrombotic milieu through various effects on the hemostatic pathways, the exact molecular mechanism leading to those effects is not known. The most common clinical presentation of estrogen-related thrombosis is venous thromboembolism (VTE) of the deep veins of the legs or pulmonary vessels, usually within the first few months of use. Estrogen has also been associated with increased risk of "unusual site" thromboses, as well as arterial thrombosis. Women at high-risk of thrombosis need careful evaluation and counseling for contraception, pregnancy, menopausal hormonal therapy and other estrogen-related conditions or treatments in order to lower the risk of thromboses. We review the most recent evidence on management of high-estrogen states in women at high-risk of thrombosis, as well as emerging data on unique populations such as transgender women. More studies are needed to better understand the pathophysiology of hormone-related thrombosis, as well as more comprehensive techniques to stratify risks for thrombosis so as to enable tailoring of recommendations for each individual.

17β-Estradiol Promotes Proinflammatory and Procoagulatory Phenotype of Innate Immune Cells in the Presence of Antiphospholipid Antibodies

Antiphospholipid syndrome (APS) is the most common cause of acquired thrombophilia and recurrent spontaneous miscarriages associated with extended persistence of antiphospholipid antibodies (aPL). How circulating aPL and high-17β-estradiol (E2) environment contribute to the pregnancy complications in APS is poorly defined. Therefore, we aimed to analyse whether E2 could be responsible for the immune cell hyperactivation in aPL- positive (lupus anticoagulant, anti-cardiolipin, anti-β2-glycoprotein) in women. For this, peripheral blood mononuclear cells (PBMCs) from 14 aPL- positive and 13 aPL- negative women were cultured in the presence or absence of E2, LPS or E2+LPS and cell immunophenotype and cytokine release were analysed. In the aPL+ group, E2 presence markedly increased the percentage of NK cells positive for CD69 (p < 0.05), monocytes positive for tissue factor (TF, CD142) (p < 0.05), and B cells expressing PD-L1 (p < 0.05), as well as the elevated production of IL-1β comparing to aPL- women (p < 0.01). Regardless of aPL positivity, E2 augmented the procoagulatory response elicited by LPS in monocytes. Our findings show the ability of E2 to promote proinflammatory and procoagulatory phenotype of innate immune cells in individuals with aPL positivity. Our data highlights the significant impact of female hormones on the activation of immune cells in the presence of aPL.

Gender differences in major adverse cardiovascular outcomes among aged over 60 year-old patients with atherosclerotic cardiovascular disease: A population-based longitudinal study in Taiwan

Atherosclerotic cardiovascular disease (ASCVD) including cerebrovascular disease (CVD), coronary artery disease (CAD), and peripheral arterial disease (PAD), contributes to the major causes of death in the world. Although several studies have evaluated the association between gender and major adverse cardiovascular outcomes in old ASCVD patients, the result is not consistent. Hence, we need a large-scale study to address this issue.This retrospective cohort study included aged over 60 year-old patients with a diagnosis of ASCVD, including CVD, CAD, or PAD, from the database contained in the Taiwan National Health Insurance Bureau during 2001 to 2004. The matched cohort was matched by age, comorbidities, and medical therapies at a 1:1 ratio. A total of 9696 patients were enrolled in this study, that is, there were 4848 and 4848 patients in the matched male and female groups, respectively. The study endpoints included acute myocardial infarction, hemorrhagic stroke, ischemic stroke, vascular procedures, in-hospital mortality, and so on. In multivariate Cox regression analysis in matched cohort, the adjusted hazard ratios (HRs) for female group in predicting acute myocardial infarction, hemorrhagic stroke, ischemic stroke, vascular procedures, and in-hospital mortality were 0.67 (P < .001), 0.73 (P = .0015), 0.78 (P < .001), 0.59 (P < .001), and 0.77 (P = .0007), respectively.In this population-based propensity matched cohort study, age over 60 year-old female patients with ASCVD were associated with lower rates of acute myocardial infarction, hemorrhagic stroke, ischemic stroke, vascular procedures, and in-hospital mortality than male patients. Further prospective studies may be investigated in Taiwan.

Do Norwegian providers comply with national recommendations when prescribing combined oral contraceptives to starters? A cohort study

OBJECTIVES

To assess whether changes in patterns of combined oral contraceptive (COC) prescriptions to starters between 2008 and 2016 were in line with changes in national recommendations for use.

DESIGN

Historical prospective cohort study.

SETTING

The national Norwegian Prescription Database.

PARTICIPANTS

Women aged 10-49 years who started COCs between 1 January 2008 and 30 June 2016, in total 285 009 women.

PRIMARY OUTCOME

The proportion of levonorgestrel-containing COC prescriptions to starters.

INTERVENTION

The Norwegian Medical Agency recommended levonorgestrel-containing COCs to starters from 2010 onwards.

RESULTS

The proportion of levonorgestrel-containing COCs prescribed to starters increased from 41% in 2008 to 80% in 2016 with the greatest increase from 2011 to 2012. This prescription pattern comprised all age groups but was observed to a lower extent among older women. Public health nurses and midwifes had the highest compliance with recommendations and prescribed levonorgestrel-containing COCs to 96% of starters aged <20 years in 2016, compared with 75% and 86% among general practitioners and doctors with no specialty.

CONCLUSION

All professions have increased the proportion of levonorgestrel-containing COC prescriptions to starters. Public health nurses and midwives had the highest compliance with the new recommendations. Future studies will examine whether this shift in prescription pattern has prevented venous thromboembolism in women of reproductive age in Norway.

Does the route of administration for estrogen hormone therapy impact the risk of venous thromboembolism? Estradiol transdermal system versus oral estrogen-only hormone therapy

OBJECTIVE

The aim of this study was to quantify the magnitude of risk reduction for venous thromboembolism events associated with an estradiol transdermal system relative to oral estrogen-only hormone therapy agents.

METHODS

A claims analysis was conducted using the Thomson Reuters MarketScan database from January 2002 to October 2009. Participants 35 years or older who were newly using an estradiol transdermal system or an oral estrogen-only hormone therapy with two or more dispensings were analyzed. Venous thromboembolism was defined as one or more diagnosis codes for deep vein thrombosis or pulmonary embolism. Cohorts of estradiol transdermal system and oral estrogen-only hormone therapy were matched 1:1 based on both exact factor and propensity score matching, and an incidence rate ratio was used to compare the rates of venous thromboembolism between the matched cohorts. Remaining baseline imbalances from matching were included as covariates in multivariate adjustments.

RESULTS

Among the matched estradiol transdermal system and oral estrogen-only hormone therapy users (27,018 women in each group), the mean age of the cohorts was 48.9 years; in each cohort, 6,044 (22.4%) and 1,788 (6.6%) participants had a hysterectomy and an oophorectomy at baseline, respectively. A total of 115 estradiol transdermal system users developed venous thromboembolism, compared with 164 women in the estrogen-only hormone therapy cohort (unadjusted incidence rate ratio, 0.72; 95% CI, 0.57-0.91; P = 0.006). After adjustment for confounding factors, the incidence of venous thromboembolism remained significantly lower for estradiol transdermal system users than for estrogen-only hormone therapy users.

CONCLUSIONS

This large population-based study suggests that participants receiving an estradiol transdermal system have a significantly lower incidence of venous thromboembolism than do participants receiving oral estrogen-only hormone therapy.

Tamoxifen treatment for male breast cancer and risk of thromboembolism: prospective cohort analysis

Purpose

Thromboembolism is a common adverse event in women treated with tamoxifen (TAM) for breast cancer. The risk in male breast cancer patients is poorly investigated. We aimed to examine the risk of thrombotic events after TAM in male breast cancer patients.

Patients and methods

In this prospective cohort study, 448 patients treated between May 2009 and July 2017 for male breast cancer (BC) were assessed for eligibility. Patients with follow-up shorter than 6 months were excluded. The cumulative risk of thromboembolism was evaluated.

Results

The median follow-up was 47 months (range 6–101 months) with a median age of 69.4 years (range 27–89 years). Oestrogen receptor and progesterone receptor expression levels were observed in 98.3 and 94.9% of cases, respectively. During the follow-up period, thrombotic events were documented in 21 (11.9%) of 177 patients receiving TAM and in 1 (2.5%) of 41 patients who did not receive tamoxifen. The estimated incidence was 51.9 per 1000 person-years and 21.5 per 1000 person-years, respectively. Notably, the highest risk was identified in the first 18 months, where 81% of the observed thrombotic events occurred. Patients aged older than 71 years had a significantly increased risk of thrombotic event under TAM treatment than their younger counterparts (p = 0.033). History of thrombotic event, cardiovascular and liver disease, as well as additional adjuvant treatment were not associated with increased thrombotic risk.

Conclusion

The risk of thrombotic event in men treated with TAM for breast cancer is markedly increased in the first 18 months of treatment, and should be considered during treatment decisions.

Sex difference in fibrin clot lysability: Association with coronary plaque composition

INTRODUCTION

Fibrin clot lysability is associated with development of cardiovascular disease (CVD). We evaluated sex-differences in fibrin clot lysability and the association with coronary plaque composition determined by computed tomography angiography (CTA).

METHODS

Middle-aged citizens without known CVD were randomly selected from a national registry. A coronary CTA assessed volumes of calcified-, non-calcified-, low-density non-calcified-, and total- plaque using a validated plaque quantification software. A non-enhanced cardiac CT scan assessed the Agatston score. Fibrin structure properties were determined using turbidimetric methods. Plasma concentrations of C-reactive protein and fibrinogen were assessed.

RESULTS

138 individuals (71 women) participated. Men more frequently had coronary plaques compared to women, P < 0.05. Coronary plaque features were comparable between men and women, P > 0.05. Women with total plaque volume > 0 mm³ had lower fibrin clot lysability compared to women with total plaque volume = 0 mm³, adjusted difference [95% confidence interval] 10.28 [1.42-19.15], P = 0.02, and a fibrinogen-dependent lower fibrin clot lysability compared to men with and without coronary plaques, 6.82 [-2.67-16.31], P = 0.16, and 8.73 [-0.43-17.89], P = 0.06, respectively. Fibrinogen correlated with all the coronary plaque features (correlation coefficient r = 0.42-0.57) only in women with total plaque volume > 0 mm³, all P < 0.01.

CONCLUSION

Asymptomatic women with coronary plaques assessed by coronary CTA have reduced fibrin clot lysability compared to both women without coronary plaques and men, suggesting a sex-dependent link between coronary atherosclerosis and fibrin clot lysability.

Tissue Factor Pathway Inhibitor, Activated Protein C Resistance, and Risk of Coronary Heart Disease Due To Combined Estrogen Plus Progestin Therapy

OBJECTIVE

To examine whether tissue factor pathway inhibitor or acquired activated protein C (APC) resistance influences the increased risk of coronary heart disease (CHD) due to estrogen plus progestin therapy.

APPROACH AND RESULTS

Prospective nested case-control study of 205 cases of CHD and 481 matched controls in the Women's Health Initiative randomized trial of estrogen plus progestin therapy. After multivariable covariate adjustment, both baseline tissue factor pathway activity (P=0.01) and APC resistance (P=0.004) were associated positively with CHD risk. Baseline tissue factor pathway activity and APC resistance singly or jointly did not significantly modify the effect of estrogen plus progestin on CHD risk. Compared with placebo, estrogen plus progestin decreased tissue factor pathway inhibitor activity and increased APC resistance but these changes did not seem to modify or mediate the effect of estrogen plus progestin on CHD risk.

CONCLUSIONS

Tissue factor pathway inhibitor activity and APC resistance are related to CHD risk in women, but may not explain the increased CHD risk due to estrogen plus progestin therapy. The data from this study do not support the clinical use of measuring these hemostatic factors to help stratify risk before hormone therapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000611.

Association of Serum Sex Hormones with Hemostatic Factors in Women On and Off Hormone Therapy: The Multiethnic Study of Atherosclerosis

BACKGROUND

Hormone therapy (HT) is associated with increased risk of both venous and arterial thrombosis, which are multifactorial in origin.

OBJECTIVES

Our objectives were twofold: first, we sought to examine associations between endogenous serum sex hormone levels and biomarkers of thrombosis and/or coagulation in postmenopausal hormone nonusers. Second, we separately studied the associations between serum sex hormone levels and biomarkers of thrombosis and/or coagulation in postmenopausal hormone users considering the fact that pattern of circulating hormones is different in women taking exogenous hormones.

PATIENTS/METHODS

We performed a cross-sectional analysis of postmenopausal women enrolled in a large multiethnic community-based cohort study, The Multiethnic Study of Atherosclerosis. We hypothesized that higher levels of estrogen-related sex hormones would be associated with biomarkers of thrombosis, suggesting mechanisms for differences in thrombotic risk from HT. Women (n = 2878) were included if they were postmenopausal and had thrombotic biomarkers (homocysteine, fibrinogen, C-reactive protein [CRP], factor VIII, and d-dimer) and sex hormone levels (total testosterone [T], bioavailable testosterone, sex hormone binding globulin [SHBG], estradiol [E2], and dehydroepiandrosterone [DHEA]) measured. A smaller random sample of 491 women also had von Willebrand factor (vWF), plasminogen activator inhibitor (PAI-1), and tissue factor pathway inhibitor (TFPI) levels measured.

RESULTS AND CONCLUSIONS

We found that elevated levels of estradiol and SHBG in HT users were associated with elevated levels of CRP and lower levels of TFPI, both of which may be related to a prothrombotic milieu in HT users. HT nonusers had far more prothrombotic associations between elevated serum sex hormone levels and thrombotic biomarkers when compared with HT users.

Endothelial dysfunction, insulin resistance and inflammation in congenital hypogonadism, and the effect of testosterone replacement

Patients with hypogonadism have poor cardiovascular and metabolic outcomes, and the effect of testosterone replacement therapy (TRT) is not clear. We investigated the presence of inflammation, insulin resistance and endothelial dysfunction in an unconfounded population of congenital hypogonadotrophic hypogonadism (CHH) and the effect of TRT on these subjects. A total of 60 patients with CHH (mean age 21.82±2.22 years) and 70 healthy control subjects (mean age 21.32±1.13 years) were enrolled. The demographic parameters, Asymmetric dimethylarginine (ADMA), TNF-like weak inducer of apoptosis (TWEAK), high sensitive C reactive protein (hs-CRP) and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured before and after TRT. The patients had higher Waist Circumferences (WC) (p=0.009), Diastolic Blood Pressures (p=0.02), Triglycerides (p=0.03), ADMA, insulin and HOMA-IR levels (p<0.001 for all) and lower TWEAK levels (p<0.001), compared to the healthy controls. After 5.56 ± 2.04 months of TRT, the patients had significantly elevated systolic blood pressures (p=0.01), body mass indexes and WC (p<0.001 and p=0.001 respectively) and decreased total and HDL cholesterol levels (p=0.032 and p<0.001 respectively). ADMA levels significantly increased (p=0.003), while the alterations in TWEAK, hsCRP and HOMA-IR were not significant. The results of the present study show that endothelial dysfunction, inflammation and insulin resistance are prevalent even in the very young subjects with CHH, who have no metabolic or cardiac problems at present. This increased cardiometabolic risk however, do not improve but even get worse after six months of TRT. Long term follow-up studies are warranted to investigate the unfavorable cardiometabolic effects of TRT.

Predictors of hospital outcome in patients with cerebral venous thrombosis

BACKGROUND

The studies regarding clinical presentations, risk factors, and outcomes of cerebral venous thrombosis (CVT) in Thai people are scarce. This study aims to identify predictors of hospital outcomes among the Thai patients with CVT.

METHODS

Patients diagnosed with CVT in Songklanagarind Hospital from January 2002 to December 2013 were identified from computerized medical record system. Demographic data, clinical presentations, associated factors, method of neuroimaging studies and results, treatment, and hospital outcomes were presented by descriptive statistics. Predictors of hospital outcomes were analyzed by both univariate and multivariate logistic regression analysis.

RESULTS

There were 90 patients with a diagnosis of CVT. The mean age (± standard deviation) was 41.22 (± 17.13) years (range, 15-80). The common clinical presentations were focal neurologic deficits (36.7%), seizure (33.3%), and cavernous sinus syndrome (32.2%). The common associated conditions were intracranial or paracranial infections (30.0%) and cancer (11.1%). Intracranial hemorrhage was found in 33 patients (36.7%). Forty-seven patients (52.2%) were dependent or death (Modified Rankin Scale [mRS], 3-6) on hospital discharge. Eleven patients (12.2%) were dead, of which 7 cases (7.78%) were CVT-related deaths. The independent predictors of dependency or death (mRS, 3-6) identified by multivariate logistic regression analysis were focal neurologic (odds ratio [OR], 14.26; 95% confidence interval [CI], 2.28-89.04; P = .001), mRS score of 3-5 on admission (OR, 35.26; 95% CI, 7.30-170.42; P = .000), and seizure (OR, .19; 95% CI, .03-1.02; P = .037).

CONCLUSIONS

Focal neurologic deficit and severely disabled patients (mRS, 3-5) on admission were independent predictors of dependency or death in CVT patients. However, seizure predicted the lower incidence of dependency or death. The characteristic findings of CVT among Thai patients were the higher incidence of cavernous sinus syndrome and rhinosinal or intracranial infection.

Testosterone therapy, thrombosis, thrombophilia, cardiovascular events

There are similar time intervals between starting testosterone therapy (TT) and development of thrombotic (~4.5 months) or cardiovascular (CVD) events (~3 months) which may, speculatively, reflect a shared pathophysiology. We have described thrombotic events 5 months (median) after starting TT in 38 men and 4 women, including 27 with deep venous thrombosis-pulmonary embolism, 12 with osteonecrosis, 1 with central retinal vein thrombosis, 1 with amaurosis fugax, and 1 with spinal cord infarction. In 8 men whose TT was continued, second thrombotic events occurred despite adequate anticoagulation with Coumadin in 8 men, 3 of whom had a third thrombotic event. Of these 42 cases, 40 had measures of thrombophilia-hypofibrinolysis, and 39 were found to have previously undiagnosed thrombophilia-hypofibrinolysis. Before beginning TT, especially in men with previous history of thrombotic events, we suggest that, at a minimum, measurements be made for the Factor V Leiden and Prothrombin mutations, Factors VIII and XI, and homocysteine, to identify men who should not receive TT. We need prospective data focused on whether there should be pre-TT screening based on history of previous venous thromboembolism or for all subjects for major gene thrombophilias. To better resolve questions about TT and all cause and cardiovascular morbidity and mortality and thrombosis, a long term, prospective, randomized, blinded study following the example of the Women's Health Initiative is needed. While we wait for prospective placebo-controlled TT outcome data, TT should be restricted to men with well-defined androgen deficiency syndromes.

Massive mesenteric and portal venous thrombosis secondary to hormone replacement therapy

Hormone replacement therapy increases risk of deep venous thrombosis (DVT) mainly in the extremities and lungs. There are reports of mesenteric ischemia secondary to oral contraceptive pills but no reports on hormone replacement therapy and mesenteric thrombosis. The authors present a case of a 44-year-old obese (BMI 32) woman, on long-term hormone replacement therapy, presented with thrombosis of portal, splenic and superior mesenteric veins. She underwent surgical resection of ischemic bowel and planned re-look laparotomies with further resections and jejuno-ileal anastomosis at final laparotomy. Thorough haematological investigations were normal. The authors conclude that hormone replacement therapy in obese patients with no other risk factors can cause a catastrophic mesenteric thrombosis. Aggressive surgical resection with re-look laparotomies and further resections can be lifesaving.

Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men

BACKGROUND

An association between testosterone therapy (TT) and cardiovascular disease has been reported and TT use is increasing rapidly.

METHODS

We conducted a cohort study of the risk of acute non-fatal myocardial infarction (MI) following an initial TT prescription (N = 55,593) in a large health-care database. We compared the incidence rate of MI in the 90 days following the initial prescription (post-prescription interval) with the rate in the one year prior to the initial prescription (pre-prescription interval) (post/pre). We also compared post/pre rates in a cohort of men prescribed phosphodiesterase type 5 inhibitors (PDE5I; sildenafil or tadalafil, N = 167,279), and compared TT prescription post/pre rates with the PDE5I post/pre rates, adjusting for potential confounders using doubly robust estimation.

RESULTS

In all subjects, the post/pre-prescription rate ratio (RR) for TT prescription was 1.36 (1.03, 1.81). In men aged 65 years and older, the RR was 2.19 (1.27, 3.77) for TT prescription and 1.15 (0.83, 1.59) for PDE5I, and the ratio of the rate ratios (RRR) for TT prescription relative to PDE5I was 1.90 (1.04, 3.49). The RR for TT prescription increased with age from 0.95 (0.54, 1.67) for men under age 55 years to 3.43 (1.54, 7.56) for those aged ≥ 75 years (p trend = 0.03), while no trend was seen for PDE5I (p trend = 0.18). In men under age 65 years, excess risk was confined to those with a prior history of heart disease, with RRs of 2.90 (1.49, 5.62) for TT prescription and 1.40 (0.91, 2.14) for PDE5I, and a RRR of 2.07 (1.05, 4.11).

DISCUSSION

In older men, and in younger men with pre-existing diagnosed heart disease, the risk of MI following initiation of TT prescription is substantially increased.

Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men

Background

An association between testosterone therapy (TT) and cardiovascular disease has been reported and TT use is increasing rapidly.

Methods

We conducted a cohort study of the risk of acute non-fatal myocardial infarction (MI) following an initial TT prescription (N = 55,593) in a large health-care database. We compared the incidence rate of MI in the 90 days following the initial prescription (post-prescription interval) with the rate in the one year prior to the initial prescription (pre-prescription interval) (post/pre). We also compared post/pre rates in a cohort of men prescribed phosphodiesterase type 5 inhibitors (PDE5I; sildenafil or tadalafil, N = 167,279), and compared TT prescription post/pre rates with the PDE5I post/pre rates, adjusting for potential confounders using doubly robust estimation.

Results

In all subjects, the post/pre-prescription rate ratio (RR) for TT prescription was 1.36 (1.03, 1.81). In men aged 65 years and older, the RR was 2.19 (1.27, 3.77) for TT prescription and 1.15 (0.83, 1.59) for PDE5I, and the ratio of the rate ratios (RRR) for TT prescription relative to PDE5I was 1.90 (1.04, 3.49). The RR for TT prescription increased with age from 0.95 (0.54, 1.67) for men under age 55 years to 3.43 (1.54, 7.56) for those aged ≥75 years (p_trend = 0.03), while no trend was seen for PDE5I (p_trend = 0.18). In men under age 65 years, excess risk was confined to those with a prior history of heart disease, with RRs of 2.90 (1.49, 5.62) for TT prescription and 1.40 (0.91, 2.14) for PDE5I, and a RRR of 2.07 (1.05, 4.11).

Discussion

In older men, and in younger men with pre-existing diagnosed heart disease, the risk of MI following initiation of TT prescription is substantially increased.

Toward a new concept of "natural balance" in oral estroprogestin contraception

The Pill has undergone many changes since its first appearance some 50 years ago. Key developments included the reduction of ethinylestradiol doses and the synthesis of new progestins in order to increase safety, compliance and efficiency. Low-dose combined oral contraceptives (COCs) are currently the preferred option for millions of women. Due to this widespread use, it has been argued that the safety of COCs should be even better, raising the threshold for excellence. Yet in spite of major improvements, there is still an associated risk of venous thromboembolism (VTE). The next step in COCs' evolution should take total estrogenicity and hepatic estro-androgenic balance into account. The focus on the estrogen component--which has not changed in 50 years--has yielded a new class of natural estrogen pills. Following the introduction of a first quadriphasic pill, a monophasic estradiol pill based on the concept of "natural balance" was subsequently made available. These recent achievements could represent a step forward in the evolution of COCs and pave the way for better safety.

Mechanisms of hormonal therapy related thrombosis

There is now compelling evidence that use of oral contraceptives and postmenopausal hormonal therapies containing various estrogens is associated with a weak, but clinically relevant risk of both arterial and venous thrombosis. The increased risk is related to type and dose of both estrogen and combined progestagen and mode of delivery. Treatment induces mainly subtle changes in individual components of the coagulation and fibrinolytic systems, but the overall effect is the induction of a prothrombotic phenotype. This brief review summarizes some of the mechanisms responsible the prothrombotic effects of such treatment.

Nomegestrol acetate-17b-estradiol for oral contraception

Oral contraceptives remain a popular method of contraception over 50 years after their introduction. While safe and effective for many women, the failure rate of oral contraception is about 8%. Concerns about the risk of venous thromboembolism continue to drive the search for the safest oral contraceptive formulations. The oral contraceptive NOMAC-E2 contains nomegestrol acetate (NOMAC) 2.5 mg + 17b-estradiol (E2) 1.5 mg. The approved dosing regimen is 24 days of active hormone, followed by a 4-day hormone-free interval. NOMAC is a progestin derived from testosterone, which has high bioavailability, rapid absorption, and a long half-life. Estradiol, though it has a lower bioavailability, has been successfully combined with NOMAC in a monophasic oral contraceptive. Two recently published randomized controlled trials demonstrate that NOMAC-E2 is an effective contraceptive, with a Pearl Index less than one pregnancy per 100 woman-years. The bleeding pattern on NOMAC-E2 is characterized by fewer bleeding/spotting days, shorter withdrawal bleeds, and a higher incidence of amenorrhea than the comparator oral contraceptive containing drospirenone and ethinyl estradiol. The adverse event profile appears to be acceptable. Few severe adverse events were reported in the randomized controlled trials. The most common adverse events were irregular bleeding, acne, and weight gain. Preliminary studies suggest that NOMAC-E2 does not seem to have negative effects on hemostatic and metabolic parameters. While no one oral contraceptive formulation is likely to be the optimum choice for all women, NOMAC-E2 is a formulation with effectiveness comparable with that of other oral contraceptives, and a reassuring safety profile.

Coagulation and fibrynolitic parameters in women and the effects of hormone therapy; comparison of transdermal and oral administration

It is established that hormone therapy (HT) is related with significant increased prothrombotic risk factor. The aim of our study was to assess the effects of oral hormone therapy (o-HT) and transdermal hormone therapy (t-HT) on hemostasis parameters: fibrinogen (Fg) concentration, the maximum velocity of polymerization of clot formation, fibrin half-time lysis, plasma level of thrombin inhibitor of fibrinolysis (TAFI) and activity of generated thrombin and plasmin amidolytic activity. We observed that values of initial velocity of polymerization in o-HT group were increased (94.64 mOD/min vs. 131.50 mOD/min, p < 0.001) compared to control group. Fibrin lysis half-time increased in both groups with HT (controls - 18.26 min vs. 32.43 min (o-HT); 23.34 min transdermal hormone therapy (t-HT) p < 0.001) compared to controls. The activity of thrombin was statistically higher in plasma of women after o-HT (72.6 ± 8.5 mOD/min) than in patients with t-HT (53.7 ± 10.1 mOD/min) and controls (51.2 ± 10 mOD/min. Plasmin activity was the highest in controls (84.5 ± 10.2 mOD/min). The highest level of TAFI we observed in patients after oral hormones (80.38 ± 8.23%); women on transdermal HT had 61.58 ± 9.81% and the lowest concentration of TAFI we noted in controls 44.70 ± 10.16). The results of our study show that HT may partly explain the increase in venous thrombosis (VTE) and cardiovascular events reported after the use of it, especially the oral form of treatment.

Venous thromboembolism associated with pregnancy and hormonal therapy

Venous thromboembolism (VTE) is a major cause of maternal morbidity and mortality during or early after pregnancy and in women taking hormonal therapy for contraception or for replacement therapy. Post-thrombotic syndrome, including leg oedema and leg pain, is an unrecognized burden after pregnancy-related VTE, which will affect more than two of five women. Women with a prior VTE, a family history of VTE, certain clinical risk factors and thrombophilia are at considerably increased risk both for pregnancy-related VTE and for VTE on hormonal therapy. This review critically assesses the epidemiology and risk factors for pregnancy-related VTE and current guidelines for prophylaxis and treatment. We also provide information on the risk of VTE related to hormonal contraception and replacement therapy.

Nicotine modulation of factor VII activating protease (FSAP) expression in human monocytes

AIM

Factor VII activating protease (FSAP) is a plasma serine protease involved in hemostasis and remodeling processes. Increased levels of circulating FSAP during pregnancy and in women using oral contraceptives (OCs) indicate that the hormonal status critically influences FSAP expression. In this respect, the aim of this study was to quantify nicotine modulation of FSAP expression in human monocytes/macrophages isolated from healthy female smokers and non-smokers, and from women who use OCs and smoke.

METHODS

FSAP concentration and activity were measured in plasma samples obtained from healthy non-pregnant, pre-menopausal, non-smoking women who did not use OCs (n=69), non-pregnant, pre-menopausal women who currently smoke and use OCs (n=43), and women who are only smokers (n=40) or currently use OCs (n=48). Expressions of FSAP mRNA and protein in monocytes isolated from healthy non-pregnant female or healthy male donors were analyzed.

RESULTS

Strongest circulating FSAP concentration and activity occurred in women with combined smoking and use of OCs compared to the control group. Enhanced FSAP levels were also observed in smoking women when compared to non-smokers. Ex vivo experiments demonstrated enhanced FSAP expression in monocytes isolated from women using OCs and currently smoking. Nicotine enhanced FSAP mRNA and protein levels in monocytes.

CONCLUSIONS

Monocytes from healthy female smokers show a constitutively enhanced FSAP expression and this effect could be replicated in vitro by stimulating monocytes with nicotine. The upregulation of FSAP due to nicotine and OC usage may be linked to a higher incidence of arteriothromboembolic diseases related to their usage.

Tissue factor pathway inhibitor, activated protein C resistance, and risk of ischemic stroke due to postmenopausal hormone therapy

BACKGROUND AND PURPOSE

To test whether changes in plasma tissue factor pathway inhibitor (TFPI) levels or activated protein C resistance (normalized activated protein C resistance ratio [nAPCsr]) modify the increased risk of ischemic stroke due to postmenopausal hormone therapy.

METHODS

Nested case-control study of 455 cases of ischemic stroke and 565 matched control subjects in the Women's Health Initiative trials of postmenopausal hormone therapy.

RESULTS

Baseline free TFPI was associated with ischemic stroke risk (OR per SD increase, 1.17; 95% CI, 1.01-1.37; P=0.039), but baseline nAPCsr was not (OR per SD increase, 0.89; 95% CI, 0.75-1.05; P=0.15). Baseline TFPI levels and nAPCsr did not modify the effect of postmenopausal hormone therapy on ischemic stroke. Treatment-induced mean changes of -28% in free TFPI and +65% in nAPCsr did not change the risk of ischemic stroke (interaction P=0.452 and 0.971, respectively). In subgroup analyses, baseline nAPCsr was inversely associated with lacunar strokes (OR per SD increase, 0.74; 95% CI, 0.57-0.96; P=0.025) and baseline free TFPI interacted with treatment to increase large vessel atherosclerotic strokes (P=0.008).

CONCLUSIONS

Procoagulant changes in TFPI or nAPCsr do not modify the increased ischemic stroke risk due to postmenopausal hormone therapy. Clinical Trial Registration- URL: www.clinicaltrials.gov. Unique identifier: NCT 00000611.

Does the route of administration for estrogen hormone therapy impact the risk of venous thromboembolism? Estradiol transdermal system versus oral estrogen-only hormone therapy

OBJECTIVE

The aim of this study was to quantify the magnitude of risk reduction for venous thromboembolism events associated with an estradiol transdermal system relative to oral estrogen-only hormone therapy agents.

METHODS

A claims analysis was conducted using the Thomson Reuters MarketScan database from January 2002 to October 2009. Participants 35 years or older who were newly using an estradiol transdermal system or an oral estrogen-only hormone therapy with two or more dispensings were analyzed. Venous thromboembolism was defined as one or more diagnosis codes for deep vein thrombosis or pulmonary embolism. Cohorts of estradiol transdermal system and oral estrogen-only hormone therapy were matched 1:1 based on both exact factor and propensity score matching, and an incidence rate ratio was used to compare the rates of venous thromboembolism between the matched cohorts. Remaining baseline imbalances from matching were included as covariates in multivariate adjustments.

RESULTS

Among the matched estradiol transdermal system and oral estrogen-only hormone therapy users (27,018 women in each group), the mean age of the cohorts was 48.9 years; in each cohort, 6,044 (22.4%) and 1,788 (6.6%) participants had a hysterectomy and an oophorectomy at baseline, respectively. A total of 115 estradiol transdermal system users developed venous thromboembolism, compared with 164 women in the estrogen-only hormone therapy cohort (unadjusted incidence rate ratio, 0.72; 95% CI, 0.57-0.91; P = 0.006). After adjustment for confounding factors, the incidence of venous thromboembolism remained significantly lower for estradiol transdermal system users than for estrogen-only hormone therapy users.

CONCLUSIONS

This large population-based study suggests that participants receiving an estradiol transdermal system have a significantly lower incidence of venous thromboembolism than do participants receiving oral estrogen-only hormone therapy.

Changes in hemostatic parameters after oral and transdermal hormone therapy in postmenopausal women

Hormone therapy (HT) can be prothrombotic risk factor. We compared the effects of oral HT (o-HT) and transdermal HT (t-HT) on the kinetic of clot formation and fibrinolysis in postmenopausal women after 6 months HT using a multiparameter test. We observed that after HT, the level of fibrinogen was higher than in controls (Fg 3.12 g/l vs. 4.24 g/l (o-HT); 3,7 g/l (t-HT); p < 0.001) and values of velocity of polymerization in o-HT group were increased (95.84 mOD/min vs. 146.50 mOD/min, p < 0.001) compared to controls. Maximum absorbance of formed clots was higher in o-HT group (0.279 vs. 0.312, p < 0.001) than in controls, but in t-HT group was lowest (0.268). Fibrin lysis half-time increased in both HT groups (controls 17.16 min vs. 31.43 min (o-HT); 23.34 min (t-HT) p < 0.001) compared to values in controls. The results of our study show that o-HT caused the changes in clot formation and fibrinolysis than t-HT in postmenopausal women. The increased level of fibrinogen and its accelerated kinetics of polymerization as well as a lower rate of clot lysis may partly explain the increase in venous thrombosis and cardiovascular events reported after the use of HT, especially the oral form of that.

Tissue factor pathway inhibitor polymorphisms in women with and without a history of venous thrombosis and the effects of postmenopausal hormone therapy

Postmenopausal hormone therapy is associated with marked reduction in tissue factor pathway inhibitor (TFPI) levels, and low TFPI levels have been associated with increased risk of venous thrombosis. Polymorphisms in the TFPI gene may affect the expression of TFPI. We aimed to investigate the influences of such polymorphisms on plasma TFPI levels and to investigate the effect of hormone therapy. Four single nucleotide polymorphisms in the TFPI gene (the -287T/C and the -399C/T polymorphisms in the 5' upstream region, and the intron 7 -33T/C and the exon 9 874G/A polymorphisms) were studied with regard to frequency, phenotype, and their influence on hormone therapy in postmenopausal women with a history of venous thrombosis (n = 138), in healthy postmenopausal women (n = 202), and in normal controls (n = 212). The frequencies of the -287C and the -33C variants were nonsignificantly lower in cases than in controls, and the polymorphisms were associated with slightly higher levels of free TFPI antigen (-287C; P = 0.076) and higher TFPI activity (-33C; P < 0.001). The -399T variant showed equal distribution in cases and controls, but was associated with lower levels of TFPI activity (P = 0.036). Conventional-dose hormone therapy induced significant reductions in TFPI levels irrespective of genotypes. In healthy women treated with low-dose hormone therapy, the reduction in TFPI levels was less pronounced with the -287C variant (P = 0.054). Our study indicates that polymorphisms in the TFPI gene may be of importance for plasma TFPI levels and for the effects of hormone therapy.

Thrombophilia and the risk of thromboembolic events in women on oral contraceptives and hormone replacement therapy

Thrombophilia contributes to the risk of thrombosis in women using female hormones. The objective of the present study was to evaluate the prevalence of thrombophilia in women with thromboembolic events (TEEs) using oral contraceptives or hormone replacement therapy (HRT) and assess the contribution of a family history and the duration of hormone use in predicting thrombosis. A retrospective analysis was performed of the case records of women who developed a TEE while on oral contraceptives or HRT and were referred for thrombophilia evaluation over a 4-year period. Among 85 women who developed a TEE while on oral contraceptives or HRT, 65 had at least one additional thrombophilia risk factor. Of the 85 cases, 23 tested positive for more than two thrombophilias, 16 had factor V Leiden, five had the prothrombin gene G20210A polymorphism, 26 had antiphospholipid antibodies, 10 had elevated homocysteine, four had protein C deficiency, and seven had protein S deficiency. There were 64 TEE: 16 pulmonary emboli, 17 cerebrovascular events, 11 intra-abdominal thromboses, 13 deep venous thromboses, five cases of superficial thrombophlebitis, and two retinal vein thromboses. Of the 65 women, 37% had a positive family history of thrombosis. Approximately half of the women had been taking oral contraceptives or HRT for more than 1 year. There is a high prevalence of thrombophilia in women who developed a TEE while using oral contraceptives or HRT for more than 1 year. Family and personal history of thrombosis should be carefully evaluated in all women before initiating or continuing oral contraceptives or HRT, and a positive history may warrant a thrombophilia screening.

Risk Factors for Heart Attack, Stroke, and Venous Thrombosis Associated With Hormonal Contraceptive Use

The search for a safe and effective method of contraception has been ongoing for centuries. During the last century, a variety of hormonal contraceptives, including combined hormonal oral contraceptives (COCs), have been introduced into the market. COCs have evolved through modifications of different hormonal components to minimize the risk of thrombotic events including stroke, myocardial infarction, and venous thrombosis. The evolution of COC development led to the reduction in the estrogen dose, in an attempt to lower the risk of vascular diseases. Although the risk of thrombotic events due to COC use has been substantially reduced since their inception, the quest for developing safer methods of birth control continues. It is of great interest to study coagulation effects of newer COCs, as well as progestin only, as rigorously as older COCs.

Factor seven ativating potease (FSAP) levels during normal pregnancy and in women using oral contraceptives

INTRODUCTION

Factor seven activating protease (FSAP) is a plasma serine protease involved in haemostasis and remodeling processes. We have investigated whether pregnancy or the use of oral contraceptives (OCs) influences circulating FSAP levels. The effect of female sex hormones on FSAP expression in cultured cells was also determined.

MATERIALS AND METHODS

FSAP levels and activity was measured in plasma samples obtained at different gestation stages from healthy pregnant women (n=101), from non-pregnant women, pre-menopausal women who currently use OCs (n=48), and non-pregnant women who did not use OCs (n=69).

RESULTS

In late pregnancy the plasma FSAP antigen (median 2.28 PEU/ml [range 1.11 to 2.62 PEU/ml]; p<0.001 vs control group) and activity (median 2.98 PEU/ml [range 1.05 to 4.24 PEU/ml]; p<0.001 vs control group) was significantly higher compared with levels in non-pregnant women and remained elevated after delivery. Plasma FSAP levels in women using OCs was also significantly elevated compared to the control group. Ex vivo experiments demonstrated enhanced FSAP expression in monocytes isolated from women using OCs. In vitro experiments showed that FSAP mRNA levels were strongly induced by estradiol in monocytes but not in hepatocytes.

CONCLUSIONS

Increased levels of circulating FSAP in pregnancy and in women using OCs indicate that hormonal status critically influences FSAP expression. Hormonal influences could be observed in monocytes in vivo and ex-vivo but not in hepatocytes indicating cell-specific regulation. Future studies designed to investigate the role of FSAP in haemostasis and remodeling processes should consider the role of female sex hormones on FSAP expression.