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

Hormone replacement therapy in women with history of thrombosis or a thrombophilia

Findings from the Women's Health Initiative (WHI) randomised placebo-controlled trial (RCT) were published at the beginning of this century. They suggested that hormone replacement therapy (HRT) use increased the risk of cardiovascular disease and venous thromboembolism including pulmonary embolism and deep vein thrombosis The findings led to a decline in HRT prescriptions and negative publicity about the use of HRT for women with significant menopausal symptoms. Subsequent studies have shown that the risk of thrombosis with HRT relates to whether estrogen is combined with a progestogen and the route of administration of estrogen. In healthy women with no background medical problems, transdermal hormone replacement is not associated with an increased risk of thrombosis. However, much less is known about the safety of various HRT preparations in women with a high background risk of thrombosis. These cases can often be challenging for clinicians with uncertainties around testing for thrombophilia, use of anticoagulation and striking a balance between the risks and benefits of prescribing HRT. This article will review the mechanism of thrombosis with differing types of HRT and present the evidence from the relevant trials. The article will also present the evidence that specifically relates to women with a personal history of thrombosis or thrombophilia (heritable and acquired) to enable clinicians to better individualise the risk assessment for each woman requesting HRT and understand the role of thrombophilia screening or concomitant anticoagulation in such situations.

Resistance to activated protein C and impaired TFPI activity in women with previous hormone-induced venous thromboembolism

INTRODUCTION

Hormonal contraception is a well-known risk factor for venous thromboembolism (VTE). APC resistance and impaired functions of protein S and TFPI are thought to play an important role in the pathogenesis of hormone-related VTE. It is unknown, whether women, who develop VTE during hormonal contraception possess a vulnerability in these pathways, making them susceptible to thrombosis.

MATERIALS AND METHODS

Plasma samples were obtained from 57 premenopausal women in average 15.3 years after hormone-associated VTE and from 31 healthy controls. Thrombin generation at high tissue factor (TF) in the absence and in the presence of activated protein C (APC) and at low TF without and with inhibiting anti-protein S- and anti-TFPI-antibodies was measured via calibrated automated thrombography.

RESULTS

Women with previous hormone-related thrombosis had higher thrombin generation at low TF, higher APC resistance, protein S- and TFPI ratios, differences: 219.9 nM IIa.min (95%CI:90.4 to 349.3); 1.88 (95%CI:0.71 to 3.05); 0.13 (95%CI:0.01 to 0.26) and 0.19 (95%CI:0.08 to 0.30), respectively. Thrombin generation at high TF without APC did not differ between the groups. Smoking decreased thrombin generation at low TF by -222.6 nM IIa.min (95%CI: -381.1 to -64.1), the APC sensitivity ratio by -2.20 (95%CI: -3.63 to -0.77) and the TFPI ratio by -0.16 (95%CI: -0.29 to -0.03), but did not influence thrombin generation at high TF.

DISCUSSION

We demonstrated impairment of the protein S/TFPI system and increased APC resistance in women with previous hormone-induced VTE. Smoking decreased thrombin generation at assay conditions, dependent on the function of the TFPI system.

Clotting factor changes during the first cycle of oral contraceptive use

OBJECTIVES

The risk of venous thromboembolism (VTE) is highest during the initial months of oral contraceptive (OC) use. We sought to evaluate the extent of hemostatic variable changes during the initial OC cycle and if such changes are related to systemic ethinyl estradiol (EE2) exposure.

STUDY DESIGN

Participants provided multiple blood samples during a 21-day OC cycle (30mcg EE2; 150mcg levonorgestrel) and after a single dose following a washout period. Analytes included D-dimer, factor VIII activity, protein C total antigen and the hepatic proteins corticosteroid-binding globulin (CBG) and sex-hormone-binding globulin (SHBG). EE2 pharmacokinetic analyses related to the 24h after the first OC tablet (OC1) and at steady state (OC21).

RESULTS

Seventeen women completed the study. D-dimer more than doubled by OC6 (p=.013) and remained elevated at OC21 (p=.012). D-dimer levels within women varied widely from day to day. Factor VIII increased 27% by OC2 (p<.001) but declined to a 9% increase by OC21. Protein C increased only 6%. EE2 steady-state area-under-the-curve ranged from 488 to 1103pg∙h/mL; higher levels were not correlated with greater increases in clotting variables. CBG and SHBG increased significantly but were not significantly correlated with levels of EE2 or with the hemostatic variables.

CONCLUSIONS

D-dimer increases during the first OC cycle were at least as great as increases seen with longer OC use. These results provide support for the increased VTE risk during initial OC use. The extreme variability in D-dimer levels may be an important component of this risk.

IMPLICATIONS

This study showed that increases in D-dimer are clearly evident in the first cycle of OC use and may be larger than are seen after a longer duration of use and thus provide biological support for the increased VTE risk during initial OC use found in epidemiological studies.

Management of Recurrent Ischemic Priapism 2014: A Complex Condition with Devastating Consequences

INTRODUCTION

The management of recurrent ischemic priapism (RIP) is not clearly defined. Given the rarity of this condition, most treatment options are supported at best by level 3 or 4 evidence.

AIM

In this article, we review the current literature regarding the pathophysiology and management of RIP and discuss the risks and benefits associated with each option, which includes ketoconazole (KTZ), 5-α-reductase inhibitors and other hormonal therapies, phosphodiesterase type 5 (PDE5) inhibitors, intracavernosal sympathomimetic injection, oral sympathomimetic agents, and other investigational therapies.

METHODS

A comprehensive literature review was performed regarding the management options for RIP.

MAIN OUTCOME MEASURE

To examine the pathophysiology of RIP and evaluate the treatment options.

RESULTS

Multiple agents have been investigated to manage RIP. KTZ, finasteride, anti-androgens, gonadotropin-releasing hormone agonists, and estrogen have been shown to be effective in several reports, though some of these agents may have significant hormonal side effects. PDE5 inhibitors currently appear to be well tolerated in this patient population, though evidence of its efficacy is limited. Intracavernosal α-agonist therapy may be used to treat episodes of priapism after they occur. Very limited data suggest terbutaline, oral α-agonists, digoxin, hydroxyurea, and gabapentin may have a role in RIP management.

CONCLUSIONS

An ideal management strategy for RIP should focus on prevention of priapic episodes using an effective, well-tolerated, cost-effective medication. We currently have several proposed options, with varying efficacy rates and side effect profiles. While significant advancements in our understanding and management of stuttering priapism have been made within the past few years, clearly continuing research and clinical studies are needed to guide our management of this disease process. Hoeh MP and Levine LA. Management of recurrent ischemic priapism 2014: A complex condition with devastating consequences. Sex Med Rev 2015;3:24-35.

Risk Factors for Venous Thromboembolism Among Reproductive Age Women

BACKGROUND

Venous thromboembolism (VTE) is rare among young women and is often presumed to occur in the setting of a genetic predisposition or during the use of estrogen-containing combined hormonal contraceptive or to have an unknown cause. This study aims to describe the distribution of VTE risk factors among women with a confirmed VTE.

METHODS

We identified all women aged 15-46 years with a VTE diagnosis at Columbia University Medical Center from 2005 to 2012 using medical center databases. We then reviewed all electronic medical records to validate the diagnoses and identify risk factors associated with each confirmed case.

RESULTS

We identified 315 cases and confirmed 186 (59%). The proportion of unconfirmed cases increased over time. Forty percent of confirmed cases were associated with hormonal contraceptives or pregnancy. Ninety-five percent of confirmed cases had identifiable major risk factors including a personal history, family history, malignancy or other predisposing illness, recent long-haul travel, trauma, hospitalization, and obesity; many had multiple simultaneous risk factors. None of the confirmed cases was associated with a previously known genetic predisposition, but in 10 confirmed cases a genetic predisposition was identified during evaluation. In only 10 of the 186 confirmed cases could we not identify any acquired risk factor, and only 2 of those 10 women had a genetic predisposition.

CONCLUSIONS

Many reproductive age women experiencing a VTE have risk factors unique to this group, and most have multiple risk factors, confirming that this is a multifactorial disease. The large proportion of unconfirmed cases suggests the need for great caution in using administrative databases for research due to poor diagnostic specificity and due to lack of information about additional risk factors.

Primary and secondary haemostasis changes related to aging

Life expectancy has increased in many countries as a result the world's population is aging. The projections indicate that the proportion of the elderly in a few decades will increase significantly. Aging carries with it a series of physiological changes; one of them is an imbalance in the hemostatic system. Thus the levels or activity of various proteins involved, such as most coagulation factors, natural anticoagulants and the fibrinolytic system are altered so that the hemostatic balance leans toward thrombosis. Also, platelet activity suggests a state of abnormal activation (P-selectin, beta thromboglobulin and platelet factor). In this review we will systematically examine the alterations in the hemostatic components that occur during aging. Therefore, understanding these hemostatic changes could contribute to developing strategies for the proper management of health in old age.

Screening women for oral contraception: can family history identify inherited thrombophilias?

OBJECTIVE

Screening for inherited thrombophilias with laboratory tests is impractical before starting women on combined oral contraceptives. As an alternative, some recommend eliciting a family history of venous thromboembolism. The validity of this approach, however, remains unclear.

DATA SOURCES

We sought all published reports that correlated a family history of venous thromboembolism with any thrombophilia confirmed by laboratory test. We used sequential, overlapping computer searches including MeSH terms used for articles in PubMed, a narrative search phrase in Google Scholar, and then all "related" articles in PubMed for each article included without time or language limitations. This was supplemented by a search of www.clinicaltrials.gov.

METHODS OF STUDY SELECTION

The search yielded 10 reports. Information was sought without success from corresponding authors of four other reports that may have had relevant data. Most reports studied atypical, high-prevalence referral populations.

TABULATION, INTEGRATION, AND RESULTS

Results were presented according to the MOOSE (Meta-analysis of observational studies in epidemiology) guidelines for systematic reviews of observational studies. The patient populations varied widely, definitions of family history included first- or first- and second-degree relatives, and the thrombophilias studied differed among these reports. Hence, aggregation of results was not possible. Despite these differences, all reports consistently documented poor validity of family history for detecting thrombophilias. Sensitivity ranged from 16% to 63% and positive predictive value from 6% to 50% for the various thrombophilias studied. In no study did family history meet the benchmark for a good test (sensitivity plus specificity greater than 150%).

CONCLUSION

Obtaining a family history of venous thromboembolism before starting combined oral contraceptives is not a valid means to detect a woman's risk of thrombophilia. Even in high-prevalence populations, in which the positive predictive value is increased, a positive family history of venous thromboembolism was no better than flipping a coin in predicting thrombophilia.

Thrombophilia and retinal vascular occlusion

Purpose

The purpose of this research was to assess associations of thrombophilia with central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), and amaurosis fugax (AF); to evaluate outcomes of normalizing high homocysteine; and to study CRVO, CRAO, and AF developing in estrogens/estrogen agonists in women subsequently shown to have thrombophilia.

Methods

Measures of thrombophilia–hypofibrinolysis were obtained in 132 CRVO cases, 15 CRAO cases, and 17 AF cases. Cases were compared to 105 healthy control subjects who did not differ by race or sex and were free of any ophthalmologic disorders. All cardiovascular disease (CVD) risk factors were compared to healthy general populations.

Main outcome measures

The main outcome measure of this study was thrombophilia.

Results

CRVO cases were more likely than controls to have high homocysteine (odds ratio [OR] 8.64, 95% confidence intervals [CI]: 1.96–38), high anticardiolipin immunoglobulin M (IgM; OR 6.26, 95% CI: 1.4–28.2), and high Factor VIII (OR 2.47, 95% CI: 1.31–7.9). CRAO-AF cases were more likely than controls to have high homocysteine (OR 14, 95% CI: 2.7–71.6) or the lupus anticoagulant (OR 4.1, 95% CI: 1.3–13.2). In four of 77 women with CRVO (two found to have high homocysteine, two with inherited high Factor XI), CRVO occurred after starting estrogen–progestins, estrogen–testosterone, or estrogen agonists. In one of eight women with CRAO found to have high anticardiolipin antibody IgG, CRAO occurred after starting conjugated estrogens, and AF occurred after starting conjugated estrogens in one of eleven women with AF (inherited protein S deficiency). Therapy for medians of 21 months (CRVO) and 6 months (CRAO-AF) was 5 mg folic acid, 100 mg B6, and 2000 mcg/day B12 normalized homocysteine in 13 of 16 (81%) CRVO cases and all five CRAO-AF cases with pretreatment hyperhomocysteinemia. The CRVO cases had an excess of hypertension; CRAO-AF cases had an excess of type 2 diabetes and hypertension.

Conclusion

Treatable thrombophilia, hyperhomocysteinemia in particular, is more common in RVO cases than in normal controls. RVO occurs after estrogens or estrogen agonists were administered in women subsequently shown to have thrombophilia.

Factor V Leiden thrombophilia

Factor V Leiden is a genetic disorder characterized by a poor anticoagulant response to activated Protein C and an increased risk for venous thromboembolism. Deep venous thrombosis and pulmonary embolism are the most common manifestations, but thrombosis in unusual locations also occurs. The current evidence suggests that the mutation has at most a modest effect on recurrence risk after initial treatment of a first venous thromboembolism. Factor V Leiden is also associated with a 2- to 3-fold increased relative risk for pregnancy loss and possibly other obstetric complications, although the probability of a successful pregnancy outcome is high. The clinical expression of Factor V Leiden is influenced by the number of Factor V Leiden alleles, coexisting genetic and acquired thrombophilic disorders, and circumstantial risk factors. Diagnosis requires the activated Protein C resistance assay (a coagulation screening test) or DNA analysis of the F5 gene, which encodes the Factor V protein. The first acute thrombosis is treated according to standard guidelines. Decisions regarding the optimal duration of anticoagulation are based on an individualized assessment of the risks for venous thromboembolism recurrence and anticoagulant-related bleeding. In the absence of a history of thrombosis, long-term anticoagulation is not routinely recommended for asymptomatic Factor V Leiden heterozygotes, although prophylactic anticoagulation may be considered in high-risk clinical settings. In the absence of evidence that early diagnosis reduces morbidity or mortality, decisions regarding testing at-risk family members should be made on an individual basis.

Estrogen and thrombosis: controversies and common sense

Soon after the introduction of hormonal oral contraceptive agents reports of thrombotic complications appeared. In the past several decades, large epidemiological studies helped defined these risks for both arterial and venous complications. Clinicians can assess a patient's risk of thrombosis by both composition of the agent and patients' personal risk factors. For women with bleeding disorders these prothrombotic changes can help decrease bleeding complications. There is now also abundant data on future management of patients with estrogen related thrombosis.