Enhancement by factor V Leiden mutation of risk of deep-vein thrombosis associated with oral contraceptives containing a third-generation progestagen

Effect over coagulation and fibrinolysis parameters of a prolonged release 24 + 4 daily use regime contraceptive formulation containing 2 mg dienogest/0.02 mg ethinylestradiol

BACKGROUND

A prolonged release combined oral contraceptive (COC) pill, containing 2 mg dienogest (DNG)/0.02 mg ethinylestradiol (EE) in a 24 + 4 daily dosing regimen has recently been approved in Europe.

OBJECTIVE

To determine if this COC impacts coagulation and fibrinolytic factors in comparison to an immediate release COC containing 3 mg drospirenone (DRSP)/0.02 mg EE.

METHOD

Forty-four patients received the novel product, and forty-seven the comparator (immediate release formulation) during nine complete cycles. Coagulation and fibrinolytic parameters were evaluated: activated protein C resistance ratio, Antithrombin III (AT III), C-reactive protein, Factor VII, Factor VIII, and D-Dimer.

RESULTS

Compared to baseline, at the end of the study both groups displayed significantly higher mean values for AT III: 1.06 mg/mL (standard deviation [SD], 95% CI, 0.98-1.15) for the DNG/EE formulation and 1.04 mg/mL (SD 95% CI, 0.96-1.12) for the comparator (p = 0.0006 and p = 0.0009, respectively). D-dimer showed a non-significant slight reduction in the DNG/EE group, from 276.62 ng/mL (SD, 95% CI, 228.92-334.26) before treatment to 243.98 ng/mL (SD, 95% CI, 192.45-309.31) ng/mL after treatment. Contrarily, the comparator displayed a non-significant rise in D-dimer values from 246.46 ng/mL (SD, 95% CI, 205.44-295.66) ng/mL to 275.30 ng/mL (SD, 95% CI 219.21-345.75; p = 0.4520). All other parameters showed no significant differences before and after the treatment for both groups.

CONCLUSION

The COC 2 mg DNG/0.02 mg EE was not associated with any meaningful changes in the analyzed coagulation and fibrinolytic parameters indicating that a prolonged release formulation does not impact on these factors.

CLINICAL TRIAL REGISTRY

EudraCT: 2019-0018-77-97.

Ischemic Stroke in Women: Understanding Sex-Specific Risk Factors, Treatment Considerations, and Outcomes

Ischemic stroke is a major cause of mortality and disability and has become a significant public health concern among women. Overall, women have more ischemic stroke events than men, in part due to their longer life span, and also suffer from more severe stroke-related disabilities compared to men. Women are also more likely than men to present with atypical non-focal neurological symptoms, potentially leading to delayed diagnosis and treatment. Female-specific risk factors, especially those related to pregnancy, are often under-recognized. A woman's risk for ischemic stroke evolves throughout her lifespan, influenced by various factors including the age of menarche, pregnancy and its complications (such as parity, pre-eclampsia/eclampsia, and preterm delivery), postpartum challenges, oral contraceptive use, and menopause. Additionally, vascular risk factors like hypertension, diabetes, and atrial fibrillation are more prevalent among older women. Despite comparable treatment efficacies, women generally experience poorer outcomes after stroke. They also face higher rates of post-stroke depression, further complicating recovery. Although significant strides have been made in reducing the incidence of ischemic stroke, our understanding of the unique risks, underlying causes, and long-term consequences for women remains limited. While sex hormones may explain some differences, a lack of awareness regarding sex-related disparities can result in suboptimal care. This review aims to illuminate the unique risks and burdens of ischemic stroke faced by women, advocating for a more nuanced understanding to enhance prevention and treatment strategies.

Beyond Birth Control: The Neuroscience of Hormonal Contraceptives

Hormonal contraceptives (HCs) are one of the most highly prescribed classes of drugs in the world used for both contraceptive and noncontraceptive purposes. Despite their prevalent use, the impact of HCs on the brain remains inadequately explored. This review synthesizes recent findings on the neuroscience of HCs, with a focus on human structural neuroimaging as well as translational, nonhuman animal studies investigating the cellular, molecular, and behavioral effects of HCs. Additionally, we consider data linking HCs to mood disorders and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and stress response as a potential mediator. The review also addresses the unique sensitivity of the adolescent brain to HCs, noting significant changes in brain structure and function when HCs are used during this developmental period. Finally, we discuss potential effects of HCs in combination with smoking-derived nicotine on outcomes of ischemic brain damage. Methodological challenges, such as the variability in HC formulations and user-specific factors, are acknowledged, emphasizing the need for precise and individualized research approaches. Overall, this review underscores the necessity for continued interdisciplinary research to elucidate the neurobiological mechanisms of HCs, aiming to optimize their use and improve women's health.

Cerebral venous sinus thrombosis: changing trends in the incidence, age and gender (findings from the CMC Vellore CVT registry)

BACKGROUND

Multiple cerebral venous sinus thrombosis (CVT) registries from various geographical regions indicate that female gender, the use of contraceptive pills, pregnancy and puerperium are important risk factors. In this study, we report the changes in the epidemiology of patients with CVT managed over the past 26 years.

METHODS

The CMC Vellore CVT registry is a prospectively maintained database at the Christian Medical College, Vellore since January 1995. Stata software was used to analyse the data and assess the changes in the incidence, age and gender distribution over the previous 26 years.

RESULTS

Among 1701 patients treated during the study period, 908 (53%) were women and 793 (47%) were men. The mean incidence of CVT was 49 per 100 000 admissions before 2010, which increased to 96 per 100 000 after 2010. Male gender had a higher odds of developing CVT (OR - 2.07 (CI 1.68 to 2.55, p<0.001). This could be attributed to the declining incidence of postpartum CVT after 2010 compared with the decade before 2010 (50% vs 20%). The mean age at presentation had increased from 24.5 to 33.2 years in the last decade.

CONCLUSIONS

There was a clear change in the gender pattern from being a condition with female preponderance, to one where equal or more men are being affected. Lower incidence of postpartum CVT cases could be the driving factor. An increase in the overall incidence of CVT cases was noted, probably due to a higher index of clinical suspicion and better diagnostic imaging modalities.

[The Thromboembolism Risk with Combined Hormonal Contraceptives: Current Status and Prescribing Practice]

The Thromboembolism Risk with Combined Hormonal Contraceptives: Current Status and Prescribing Practice Abstract. The use of combined hormonal contraceptives (CHC) increases not only the risk for venous thromboembolism, but also for arterial thromboembolism. The risk for thromboembolism is the same for non-oral CHC (patches, vaginal rings) as for oral CHC. Risk factors such as age >35, obesity, smoking and a positive family history need to be recognized and considered in contraceptive counselling. Elaborate information concerning risks and benefits is mandatory. This applies to first-time as well as long-term users. Careful investigation of the history is required, and the risk factors need to be re-evaluated at yearly prescription. It is also very important to inform the patients about the early symptoms of thrombosis or pulmonary embolism, so that therapy can be started immediately. Apart from these risks, CHC may have beneficial effects on organs such as the ovaries, the endometrium and the general well-being for many women. When prescribing a CHC for the first time or when changing to another preparation, one should always weigh up whether certain benefits justify prescribing a preparation with a slightly higher risk of thrombosis compared to the second-generation pill or preparations with Estradiol/Nomegestrolacetat. Women who are already using a third-generation pill or a pill with drospirenone or cyproterone acetate and feel comfortable with it do not need to switch to another preparation (provided no new risk factors have arisen). For women with increased risks, i.e. several relative contraindications or one absolute contraindication, safe alternatives to CHC include progestogen-only preparations, intrauterine devices containing copper or levonorgestrel or, after family planning has been completed, surgical methods (sterilisation/vasectomy).

Oral contraceptives and stroke: Foes or friends

Incidents of strokes are increased in young women relative to young men, suggesting that oral contraceptive (OC) use is one of the causes of stroke among young women. Long-term exposures to the varying combinations of estrogen and progestogen found in OCs affect blood clotting, lipid and lipoprotein metabolism, endothelial function, and de novo synthesis of neurosteroids, especially brain-derived 17β-estradiol. The latter is essential for neuroprotection, memory, sexual differentiation, synaptic transmission, and behavior. Deleterious effects of OCs may be exacerbated due to comorbidities like polycystic ovary syndrome, sickle cell anemia, COVID-19, exposures to endocrine disrupting chemicals, and conventional or electronic cigarette smoking. The goal of the current review is to revisit the available literature regarding the impact of OC use on stroke, to explain possible underlying mechanisms, and to identify gaps in our understanding to promote future research to reduce and cure stroke in OC users.

Combined Oral Contraceptives and Venous Thromboembolism: Review and Perspective to Mitigate the Risk

Many factors must be considered and discussed with women when initiating a contraceptive method and the risk of venous thromboembolism (VTE) is one of them. In this review, we discuss the numerous strategies that have been implemented to reduce the thrombotic risk associated with combined oral contraceptives (COCs) from their arrival on the market until today. Evidences suggesting that COCs were associated with an increased risk of VTE appeared rapidly after their marketing. Identified as the main contributor of this risk, the dosage of the estrogen, i.e., ethinylestradiol (EE), was significantly reduced. New progestins were also synthetized (e.g., desogestrel or gestodene) but their weak androgenic activity did not permit to counterbalance the effect of EE as did the initial progestins such as levonorgestrel. Numerous studies assessed the impact of estroprogestative combinations on hemostasis and demonstrated that women under COC suffered from resistance towards activated protein C (APC). Subsequently, the European Medicines Agency updated its guidelines on clinical investigation of steroid contraceptives in which they recommended to assess this biological marker. In 2009, estradiol-containing COCs were marketed and the use of this natural form of estrogen was found to exert a weaker effect on the synthesis of hepatic proteins compared to EE. In this year 2021, a novel COC based on a native estrogen, i.e., estetrol, will be introduced on the market. Associated with drospirenone, this preparation demonstrated minor effects on coagulation proteins as compared with other drospirenone-containing COCs. At the present time, the standard of care when starting a contraception, consists of identifying the presence of hereditary thrombophilia solely on the basis of familial history of VTE. This strategy has however been reported as poorly predictive of hereditary thrombophilia. One rationale and affordable perspective which has already been considered in the past could be the implementation of a baseline screening of the prothrombotic state to provide health care professionals with objective data to support the prescription of the more appropriate contraceptive method. While this strategy was judged too expensive due to limited laboratory solutions, the endogenous thrombin potential-based APC resistance assay could now represent an interesting alternative.

Overall and bleeding-related discontinuation rates of a new oral contraceptive containing 4 mg drospirenone only in a 24/4 regimen and comparison to 0.075 mg desogestrel

OBJECTIVES

Progestin-only pills do not increase the risk of venous thromboembolism, stroke, and myocardial infarction but are associated with poor cycle control. A novel estrogen-free pill containing only drospirenone (DRSP) to improve bleeding patterns and tolerability and reduce discontinuation rates has been introduced into the market. The present study aims to describe the improvement in the acceptability of this DRSP-only pill, e.g. regarding the bleeding profile and the reduction in discontinuation rates due to unacceptable bleeding compared to desogestrel (DSG).

STUDY DESIGN

Double-blind, double-dummy prospective phase III study in healthy women aged 18-45 years evaluating a total of 858 women with 6691 DRSP and 332 women with 2487 DSG treatment cycles.

RESULTS

Overall, 82 (9.6%) women in the DRSP group and 44 (13.3%) women in the DSG group experienced treatment-emergent adverse events (TEAEs) leading to premature termination of the trial meaning that 32% more women in the DRSP group finished the trial in comparison to the DSG group (based on the AUC of Kaplan-Meier's curves). Discontinuation rates due to abnormal bleeding were 3.7% for DRSP and 7.3% for DSG users. This is a 55.7% lower discontinuation rate in the DRSP group compared to the DSG group.

CONCLUSIONS

This report describes the improvement in acceptability and bleeding profile of women using the new DRSP-only oral contraceptive compared to DSG, providing a better quality of life and adherence to the contraceptive method as demonstrated by lower discontinuation rates of women using the estrogen-free DRSP-only pill.

Appraising screening, making risk in/visible. The medical debate over Non-Rare Thrombophilia (NRT) testing before prescribing the pill

Non-rare thrombophilia (NRT) are hereditary predispositions to thromboembolism, the most severe side effect of combined hormonal contraception. In the mid-1990s, the identification of NRT stirred up a controversy over the possibility of investigating these genetic variants in women wishing to use contraception. Through a review of literature, this article reconstructs the debate over whether and how this genetic test should be prescribed as a way to reconfigure the risk visibility on pharmacological contraception. The main arguments identified concern the epidemiological, social, economic and clinical aspects of the test. In a context where the overall thrombotic risk for hormonal contraception is largely invisible, the genetic tests turn to embody the thrombotic risk itself. Those who opt for selective screening argue that a better estimation of risk implies a test prescription embed in a global medical assessment of women's individual risk. To advocates of universal or 'extended' screening, the tests are valuable tools to inform women on the thrombotic risk and, as such, appraised as a moral/legal obligation, whatever their predictive power. Risk visibility thus appears as an insightful concept to analyse a complex setting associating clinical, political, social and cultural considerations that touches upon medical power, women's responsibility and drug safety.

Hormonal Contraceptives and the Risk of Venous Thrombosis

The risk of venous thrombosis (VT) varies according to the type of progestogen that is found in combined oral contraceptives (COCs). When combined with the estrogen component ethinylestradiol (EE), the androgenic progestogens are better able to counteract the EE-induced stimulation of liver proteins and hence are associated with a twofold decreased risk of VT compared with non- or antiandrogenic progestogens, which exert limited counteraction of EE. Because EE is responsible for the increased risk, novel estrogens such as estradiol were developed and seem to have a lower risk of VT than EE. Besides COCs, there are other methods of hormonal contraceptives, such as progestogen-only contraceptives, which do not increase VT risk, except for injectables. Other nonoral contraceptives are combined vaginal rings and patches. There is insufficient evidence regarding the risk of VT associated with these two methods compared with COCs. The increased risk associated with COCs is more pronounced in women with inherited thrombophilia. In these women, the progestogen levonorgestrel seems to be associated with the lowest risk of VT. Currently, there are no studies that have investigated the risk of VT in women who switch COCs. We hypothesize that switching COCs, even when switching from a high- to a low-risk COC, increases the risk of VT. Finally, risk prediction models in women who use COCs are lacking. Since there is a large number of VT cases associated with COC use, it is important to identify women at risk of VT and advise them on alternative contraception methods.

The French pill scare and the reshaping of social inequalities in access to medical contraceptives

While the consequences of various "pill scares" have been relatively well-documented in the public health literature revealing a drop in pill use and a rise in unplanned pregnancies and abortion rates, researchers rarely considered that these controversies would affect women contraceptive practices differently according to their social background. Indeed, social differentiations in reaction to "pill scares" could contribute to reinforce the social gradient in the use of contraceptive methods and choice of visiting the health professionals who prescribe them. These could contribute to an increase in health inequalities on access to contraceptive methods. Using data from three state nationally representative cross-sectional surveys conducted in France in 2010, 2013 and 2016, we studied the changes in women's contraceptive uses around the French "pill scare" that occurred in 2012-2013. We focused on the changes in the use of all contraceptives available under medical prescription (called medical contraceptives) on one hand, and on each specific method (pill, IUD, implant, patch or vaginal ring, and female sterilization) on the other hand according to the women's social background. We saw a social gradient in contraceptives changes. The decline in the use of contraceptive methods available under medical prescription was particularly marked for women from lower and higher classes in which we observe a decrease in pill use between 2010 and 2013, whereas it was observed only between 2013 and 2016 among middle class women. Moreover, while some women from upper class shifted from pill to IUD between 2010 and 2013, this was not the case for their less privileged counterparts. As a consequence, it seems that the French "pill scare" led to the reshaping of social inequalities in access to medical contraceptives.

The joint effect of genetic risk factors and different types of combined oral contraceptives on venous thrombosis risk

It is not known whether the synergistic effect of genetic markers, increasing the risk of venous thrombosis (VT), and combined oral contraceptives (COC) use varies between different types of progestogens in these preparations. We investigated the joint effect of genetic risk factor, that is, F5 rs6025, F2 rs1799963, and FGG rs2066865 mutations, and different progestogens on the risk of VT. The constrained maximum likelihood estimation (CMLE) method was used to calculate joint effects, expressed as odds ratio (OR) with 95% confidence intervals [CI]. As the dose of estrogen is known to be a risk factor for VT, analyses were restricted to COC with 30 µg estrogen and each progestogen. Overall, the joint effect of COC and genetic variants was lowest for COC containing the progestogen levonorgestrel, albeit CIs were wide. The OR (95% CI) of the four different analyses (i.e. joint effect with F5 rs6025, F2 rs1799963, F5 rs6025 or F2 rs1799963 and FGG rs2066865) ranged between 7·4 (5·4–10·2) and 24·8 (12·3–50·0) for levonorgestrel. For gestodene the joint effect ranged between 11·7 (7·2–19·1) and 30·9 (10·6–89·9). Desogestrel and cyproterone acetate had the highest risk estimates: 14·6 (9·7–21·9) and 32·6 (13·2–80·6) and 15·5 (9·7–24·9) and 44·4 (16·9–116·3) respectively. In women with inherited thrombophilia, COC containing levonorgestrel were associated with the lowest risk of VT, albeit the CIs were wide.

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.

Systematic Review of Hormonal Contraception and Risk of Venous Thrombosis

Background

Hormonal contraception (HC) is widely used throughout the world and has been associated with venous thrombosis (VT) such as deep vein thrombosis, pulmonary emboli, and cerebral VT.

Objectives

To provide a current comprehensive overview of the risk of objectively confirmed VT with HC in healthy women compared to nonusers.

Search methods

PubMed was searched from inception to April 2018 for eligible studies in the English language, with hand searching from past systematic reviews.

Selection criteria

We selected original research evaluating risk of objectively confirmed VT in healthy women taking oral or nonoral HC compared with nonusers.

Data collection

The primary outcome of interest was a fatal or nonfatal VT in users of HC compared to nonusers or past users. Studies with at least twenty events were eligible. Adjusted relative risks with 95 percent confidence intervals were reported. Three independent reviewers extracted data from selected studies.

Results

1,962 publications were retrieved through the search strategy, with 15 publications included. Users of oral contraception with levonorgesterol had increased risk of VT by a range of 2.79-4.07, while other oral hormonal preparations increased risk by 4.0-48.6. Levonorgestrel intrauterine devices did not increase risk. Etonogestrel/ethinyl estradiol vaginal rings increased the risk of VT by 6.5. Norelgestromin/ethinyl estradiol patches increased risk of VT by 7.9. Etonogestrel subcutaneous implants by 1.4 and depot-medroxyprogesterone by 3.6. The risk of fatal VT was increased in women aged fifteen to twenty-four by 18.8-fold.

Conclusion

Users of HC have a significant increased risk of VT compared to nonusers. Current risks would project at least 300-400 healthy young women dying yearly in the United States due to HC. Women should be informed of these risks and offered education in fertility-awareness-based methods with comparable efficacy for family planning.

Summary

HC is widely used throughout the world and has been associated with blood clots in the legs and lungs. We searched the literature and found the risks of currently used forms of birth control increased between three- and ninefold for blood clots for healthy women. The risks found would project 300-400 women dying from using HC each year in the United States.

A systematic review and meta-analysis of venous thrombosis risk among users of combined oral contraception

Background

Combined oral contraceptives (COCs) containing various progestogens could be associated with differential risks for venous thromboembolism (VTE).

Objective

To evaluate the comparative risks of VTE associated with the use of low‐dose (less than 50 μg ethinyl estradiol) COCs containing different progestogens.

Search strategy

PubMed and the Cochrane Library were searched from database inception through September 15, 2016, by combining search terms for oral contraception and venous thrombosis.

Selection criteria

Studies reporting VTE risk estimates among healthy users of progestogen‐containing low‐dose COCs were included.

Data collection and analysis

A random‐effects model was used to generate pooled adjusted risk ratios and 95% confidence intervals; subgroup and sensitivity analyses assessed the impact of monophasic‐COC use and study‐level characteristics.

Main results

There were 22 articles included in the analysis. The use of COCs containing cyproterone acetate, desogestrel, drospirenone, or gestodene was associated with a significantly increased risk of VTE compared with the use of levonorgestrel‐containing COCs (pooled risk ratios 1.5–2.0). The analysis restricted to monophasic COC formulations with 30 μg of ethinyl estradiol yielded similar findings. After adjustment for study characteristics, the risk estimates were slightly attenuated.

Conclusions

Compared with the use of levonorgestrel‐containing COCs, the use of COCs containing other progestogens could be associated with a small increase in risk for VTE.

Combined oral contraceptives containing certain progestogens could be associated with a small increase in risk for venous thromboembolism compared with those containing levonorgestrel.

Risks of thromboembolism associated with hormone contraceptives in Japanese compared with Western women

We extracted 581 thromboembolic events associated with combined oral contraceptives (COC) that occurred between 2004 and 2013 in Japan, from the Pharmaceuticals and Medical Devices Agency database. The most common thromboembolic events associated with COC were deep vein thrombosis, pulmonary embolism and their combination. The reported thromboembolic events increased year by year, in association with an increase in the quantity of prescribed low-dose estrogen progestin after approval for health insurance coverage for dysmenorrhea in 2008 in Japan. The incidence of venous thromboembolism (VTE) in Japanese COC users is estimated to be lower compared with their Western counterparts. In contrast, the frequency of all thromboembolic events peaked at 90 days from the start of COC, as in Western studies. The risk of VTE in the overweight group (body mass index ≥ 25 kg/m² ) was more than twofold higher than in the standard group, and age-specific incidence rate rose sharply after the age of 40. There were different VTE risks according to progestin type in Japan as in Western countries, but a definite conclusion about risk according to progestin type was not able to be reached at present. As for the risk of arterial embolism and thrombosis, the difference by progestin type was small, but it became higher at ≥50 years of age. Last, mortality rate caused by thromboembolism is extremely low among COC users.

Reduced Prothrombinase Inhibition by Tissue Factor Pathway Inhibitor Contributes to the Factor V Leiden Hypercoagulable State

Activated factor V (FVa) and factor X (FXa) form prothrombinase, which converts prothrombin to thrombin. The α isoform of tissue factor (TF) pathway inhibitor (TFPI) dampens early procoagulant events, partly by interacting with FV. FV Leiden (FVL) is the most common genetic thrombophilia in Caucasians. Thrombosis risk is particularly elevated in women with FVL taking oral contraceptives, which produce acquired TFPIα deficiency. In mice, FVL combined with 50% reduction in TFPI causes severe thrombosis and perinatal lethality. However, a possible interaction between FVL and TFPIα has not been defined in humans. Here, we examined this interaction using samples from patients with FVL in thrombin generation and fibrin formation assays. In dilute TF- or FXa-initiated reactions, these studies exposed a TFPI-dependent activation threshold for coagulation initiation that was greatly reduced by FVL. The reduced threshold was progressively overcome with higher concentrations of TF or FXa. Plasma assays using anti-TFPI antibodies or a TFPI peptide that binds and inhibits FVa demonstrated that the decreased activation threshold resulted from reduced TFPIα inhibition of prothrombinase. In assays using purified proteins, TFPIα was a 1.7-fold weaker inhibitor of prothrombinase assembled with FVL than with FV. Thus, FVL reduces the threshold for initiating coagulation, and this threshold is further reduced in situations of low TFPIα concentration. Individuals with FVL are likely prone to thrombosis in response to weak procoagulant stimuli that would not initiate blood clot formation in individuals with FV.

Oral Contraceptives and HRT Risk of Thrombosis

Estrogen-containing medication, prescribed either for contraception in women of reproductive age or for prevention of cardiovascular events and osteoporosis as well as for alleviation of symptoms related to menopause, is associated with changes in the hemostatic balance and contributes to increased risk of development of venous thromboembolic complications. This risk is dose and medication dependent, increases with age, congenital and/or acquired predisposition to thrombosis, and mode of administration. This review attempts to summarize the current knowledge regarding the pathophysiology of oral contraceptive (OC) and hormone replacement therapy (HRT) -induced prothrombotic state in women, the risk of thrombosis associated with administration of various commercially available OCs and HRT, the additional risk in women with hereditary or acquired thrombophilia, and the currently available recommendations regarding massive screening of women for thrombophilia prior to initial prescription or continuation of treatment with OCs and HRT preparations.

Venous Thromboembolism Due to Oral Contraceptive Intake and Spending Nights in a Vehicle -A Case from the 2016 Kumamoto Earthquakes

A 40-year-old woman experiencing sudden dyspnea went to her personal doctor for advice. She was previously diagnosed with endometriosis and prescribed oral contraceptives for treatment. During earthquakes, she spent 7 nights sleeping in a vehicle. The patient had swelling and pain in her left leg and high D-dimer concentration levels. A contrast-enhanced computed tomography scan revealed a contrast deficit in the bilateral pulmonary artery and in the left lower extremity. She was diagnosed with pulmonary thromboembolism (PTE), and anticoagulation therapy was initiated. This present case is the first report of PTE attributed to the use of oral contraceptives after earthquakes.

Endotoxaemia-augmented murine venous thrombosis is dependent on TLR-4 and ICAM-1, and potentiated by neutropenia

Venous thromboembolism is a major cause of death during and immediately post-sepsis. Venous thrombosis (VT) is mediated by cell adhesion molecules and leukocytes, including neutrophil extracellular traps (NETs). Sepsis, or experimentally, endotoxaemia, shares similar characteristics and is modulated via toll like receptor 4 (TLR4). This study was undertaken to determine if endotoxaemia potentiates early stasis thrombogenesis, and secondarily to determine the role of VT TLR4, ICAM-1 and neutrophils (PMNs). Wild-type (WT), ICAM-1^-/- and TLR4^-/- mice underwent treatment with saline or LPS (10 mg/kg i. p.) alone, or followed by inferior vena cava (IVC) ligation to generate stasis VT. In vivo microscopy of leukocyte trafficking was performed in non-thrombosed mice, and tissue and plasma were harvested during early VT formation. Pre-thrombosis, circulating ICAM-1 was elevated and increased leukocyte adhesion and rolling occurred on the IVC of LPS-treated mice. Post-thrombosis, endotoxaemic mice formed larger, platelet-poor thrombi. Endotoxaemic TLR4^-/- mice did not have an augmented thrombotic response and exhibited significantly decreased circulating ICAM-1 compared to endotoxaemic WT controls. Endotoxaemic ICAM-1^-/- mice had significantly smaller thrombi compared to controls. Hypothesising that PMNs localised to the inflamed endothelium were promoting thrombosis, PMN depletion using anti-Ly6G antibody was performed. Paradoxically, VT formed without PMNs was amplified, potentially related to endotoxaemia induced elevation of PAI-1 and circulating FXIII, and decreased uPA. Endotoxaemia enhanced early VT occurs in a TLR-4 and ICAM-1 dependent fashion, and is potentiated by neutropenia. ICAM-1 and/or TLR-4 inhibition may be a unique strategy to prevent sepsis-associated VT.

Combined hormonal contraception and the risk of venous thromboembolism: a guideline

While venous thromboembolism (VTE) is rare in young women of reproductive age, combined oral contraceptives increase the risk of VTE. In the patient in whom combined hormonal contraception is appropriate, it is reasonable to use any currently available preparation.

A Review of Hormonal Contraception and Venous Thromboembolism in Adolescents

BACKGROUND

The number of adolescents who are prescribed hormonal contraception (HC) for contraceptive and noncontraceptive indications is increasing. Approximately 1 of 4 female adolescents will use some form of HC by age 19 years. Venous thromboembolism (VTE) is a rare, but life-threatening complication associated with HC use. Although adolescents aged 15 to 19 years have the lowest absolute HC-associated VTE risk, they still account for 5.9% of HC-associated VTE. The absolute HC-associated VTE risk for those younger than 15 years of age is not well described.

OBJECTIVE

The objectives of this report are to describe the current literature regarding HC-associated VTE in adolescents, to review the coagulation cascade and in vivo coagulation, to highlight differences between the adolescent and adult coagulation profiles, to discuss coagulation profile changes related to HC use, and to identify knowledge deficits for future study.

CONCLUSION

The mechanisms and confounding variables that lead to HC-associated VTE in all adolescents are not well understood because many large HC studies exclude female adolescents younger than 18 years of age. Because of the paucity of data in this age group, observational studies and randomized controlled trials of VTE risk in adolescents on varying forms of HC are needed. Studies should include female adolescents across the entire adolescent age span (12-21 years) to better understand HC-associated VTE risk in this population.

Suppression of liver Apo E secretion leads to HDL/cholesterol immaturity in rats administered ethinylestradiol

Ethinylestradiol (EE), a main component of the combined oral contraceptive pill, is associated with an increased risk of arterial diseases. However, the toxicity mechanism of EE is poorly understood. In this study, we found that the exposure to EE reduced the serum apolipoprotein E (Apo E) level and high-density lipoprotein (HDL)/cholesterol concentration in adult female rats. Diethylstilbestrol showed the same effects and both reductions were suppressed by coadministration of tamoxifen (TAM). Liver perfusion experiments revealed that the secretion rate of Apo E from the liver was significantly reduced. It is concluded that EE damages the maturation of HDL/cholesterol by delaying Apo E secretion from the liver, and this may lead to an increased risk of arterial diseases, such as atheromas.

Progestin isoforms provide different levels of protein S expression in HepG2 cells

INTRODUCTION

Use of combined oral contraceptives (COCs) results in acquired protein S (PS) deficiency, a well-established risk factor for venous thromboembolism (VTE). The risk of VTE due to COCs containing newer-generation progestins is double compared with COCs containing older-generation progestins, although there is little difference in estrogen contents between the generations. In contrast, progestin-only contraceptives do not confer an increased risk of VTE. In this study, we aimed to investigate how different isoforms of progestin in COCs affect the risk of VTE by measuring PS expression.

MATERIALS AND METHODS

The effect of progestin, levonorgestrel (LNG) or drospirenone (DRSP), on PS mRNA expression in HepG2 cells was measured using reverse transcription-quantitative PCR; PS level was determined using Western blot analysis. PROS1 promoter activity, PS mRNA stability, and de novo synthesis of PS mRNA were examined in HepG2 cells after treatment with progestin.

RESULTS AND CONCLUSIONS

In the presence of progestins, PS mRNA and protein expressions were significantly upregulated in HepG2 cells due to the augmentation of de novo PS mRNA expression modulated by RNA polymerase II (Pol II), thereby facilitating PS transcription elongation. Moreover, the transcription elongation inhibitor blocked progestin-mediated de novo PS mRNA expression. Conversely, progestin did not affect PROS1 promoter activity and PS mRNA stability. Pol II elongation efficiency in the newer-generation progestin (DRSP) treatment was not as strong compared with older-generation progestin (LNG), suggesting the difference in VTE risk between COC generations.

Review: Contraception in adolescents with systemic lupus erythematosus

In the management of adolescents with systemic lupus erythematosus (SLE), sexual activity and prevention of unwanted pregnancies are important topics. Many contraceptive methods are available nowadays. Oral contraceptives (OCs) are the preferred choice among adolescents in general. However, the use of these medications in adolescents with SLE raises serious concerns, particularly the risk of thrombotic events from estrogen exposure and the impact of these medications on lupus activity. In this article, different contraceptive methods available are reviewed and their application in adolescents with SLE is discussed. In conclusion, OCs are the methods of choice in adolescents with stable disease and no antiphospholipid antibodies (aPL) detected. In patients with aPL, fewer options are available, and the selection of the preferred form of contraception should be made on an individual basis. Lupus (2007) 16, 600—605.

Combined oral contraceptives, thrombophilia and the risk of venous thromboembolism: a systematic review and meta-analysis

Essentials We performed a meta-analysis on thrombosis risk in thrombophilic oral contraceptive (COC)-users. The results support discouraging COC-use in women with a natural anticoagulant deficiency. Contrary, additive risk of factor V Leiden (FVL) or prothrombin-G20210A (PT) mutation is modest. Women with a FVL/PT-mutation as single risk factor can use COCs if alternatives are not tolerated.

SUMMARY

Background Combined oral contraceptives (COCs) are associated with an increased risk of venous thromboembolism (VTE), which is shown to be more pronounced in women with hereditary thrombophilia. Currently, WHO recommendations state that COC-use in women with hereditary thrombophilias (antithrombin deficiency, protein C deficiency, protein S deficiency, factor V Leiden and prothrombin-G20210A mutation) is associated with an unacceptable health risk. Objective To perform a meta-analysis evaluating the additional risk of VTE in COC-users with thrombophilia. Methods The MEDLINE and EMBASE databases were searched on 10 February 2015 for potential eligible studies. A distinction was made between 'mild' (factor V Leiden and prothrombin-G20210A mutation) and 'severe' thrombophilia (antithrombin deficiency, protein C deficiency, protein S deficiency, double heterozygosity or homozygosity of factor V Leiden and prothrombin-G20210A mutation). Results We identified 12 case-control and three cohort studies. In COC-users, mild and severe thrombophilia increased the risk of VTE almost 6-fold (rate ratio [RR], 5.89; 95% confidence interval [CI], 4.21-8.23) and 7-fold (RR, 7.15; 95% CI, 2.93-17.45), respectively. The cohort studies showed that absolute VTE risk was far higher in COC-users with severe thrombophilia than in those with mild thrombophilia (4.3 to 4.6 vs. 0.49 to 2.0 per 100 pill-years, respectively), and these differences in absolute risks were also noted in non-affected women (0.48 to 0.7 vs. 0.19 to 0.0), but with the caveat that absolute risks were estimated in relatives of thrombophilic patients with VTE (i.e. with a positive family history). Conclusion These results support discouraging COC-use in women with severe hereditary thrombophilia. By contrast, additive VTE risk of mild thrombophilia is modest. When no other risk factors are present, (e.g. family history) COCs can be offered to these women when reliable alternative contraceptives are not tolerated.

State-of-the-Art Review: Activated Protein C Resistance: Clinical Implications

The discovery of inherited resistance to activated protein C (APC) as a major risk factor for venous thrombosis has dramatically improved our understanding of the pathogenesis of venous thrombosis. In a majority of cases, APC resistance is associated with a single point mutation in the factor V gene (FV) that results in substitution of arginine, R, at position 506 by glutamine, Q. (FV:Q506). The mutation renders factor Va partially resistant to degradation by APC. A functional APC resistance test, which includes predilution of the patient plasma with factor V-deficient plasma, is found to be 100% sensitive and specific for the presence of FV:Q506and is useful as a screening assay. Carriers of the FV:Q506allele have increased thrombin generation, resulting in hypercoagulability and a lifelong increased risk of venous thrombosis. In Western countries, APC resistance due to the FV mutation is present in 20-60% of thrombosis patients and in 1-15% of healthy controls, whereas the mutation is virtually absent from ethnic groups other than Caucasians. This may explain the high incidence of venous thrombosis in Western countries. The thrombotic risk in APC-resistant individuals may be further increased by other genetic defects, e.g., protein C or protein S deficiency, and by exposure to circumstantial risk factors, e.g., oral contraceptives, pregnancy, immobilization, and surgery. The question is thus raised as to whether general screening for APC resistance before circumstantial risk factors occur is warranted in Western countries. Key Words: Factor V—APC resistance-Protein C-Protein S—Thrombosis—Mutation.

The birth control pill, thromboembolic disease, science and the media: a historical review of the relationship

The introduction of the birth control pill (the Pill) in 1960 revolutionized the options for contraception, sparking vibrant discussion in the scientific and social science literature and in the media. Much attention focused on issues of women's rights, including ethics and personal choice. But the Pill also introduced new questions about risk. Shortly after its introduction, the risk of thromboembolic disease was recognized [1]. After more than half a century, controversies about the relationship between the Pill and thromboembolic disease have persisted. The scientific and media communities have been active in the discussion, debate and delivery of information about this risk. Scientific and public attention to thromboembolism and the Pill has had dramatic consequences, both good and bad. The spotlight on risk has helped to change norms regarding the public's right to know and assess dangers; it has sparked Pill scares linked to increased unplanned pregnancy, birth and abortion rates; and it has led to a change in federally mandated policies regarding how new contraceptive products are studied and brought to market. This paper charts the narrative of the thromboembolic risk of the Pill from its introduction in 1960 until today and reviews the corresponding media response to this history. How does the story of the thromboembolic risk of the Pill - explored through the lens of science, media and contemporary social dynamics - frame contemporary understanding of risk for researchers, clinicians, individuals and the public?

Low dose oestrogen combined oral contraception and risk of pulmonary embolism, stroke, and myocardial infarction in five million French women: cohort study

OBJECTIVE

To assess the risk of pulmonary embolism, ischaemic stroke, and myocardial infarction associated with combined oral contraceptives according to dose of oestrogen (ethinylestradiol) and progestogen.

DESIGN

Observational cohort study.

SETTING

Data from the French national health insurance database linked with data from the French national hospital discharge database.

PARTICIPANTS

4 945 088 women aged 15-49 years, living in France, with at least one reimbursement for oral contraceptives and no previous hospital admission for cancer, pulmonary embolism, ischaemic stroke, or myocardial infarction, between July 2010 and September 2012.

MAIN OUTCOME MEASURES

Relative and absolute risks of first pulmonary embolism, ischaemic stroke, and myocardial infarction.

RESULTS

The cohort generated 5 443 916 women years of oral contraceptive use, and 3253 events were observed: 1800 pulmonary embolisms (33 per 100 000 women years), 1046 ischaemic strokes (19 per 100 000 women years), and 407 myocardial infarctions (7 per 100 000 women years). After adjustment for progestogen and risk factors, the relative risks for women using low dose oestrogen (20 µg v 30-40 µg) were 0.75 (95% confidence interval 0.67 to 0.85) for pulmonary embolism, 0.82 (0.70 to 0.96) for ischaemic stroke, and 0.56 (0.39 to 0.79) for myocardial infarction. After adjustment for oestrogen dose and risk factors, desogestrel and gestodene were associated with statistically significantly higher relative risks for pulmonary embolism (2.16, 1.93 to 2.41 and 1.63, 1.34 to 1.97, respectively) compared with levonorgestrel. Levonorgestrel combined with 20 µg oestrogen was associated with a statistically significantly lower risk than levonorgestrel with 30-40 µg oestrogen for each of the three serious adverse events.

CONCLUSIONS

For the same dose of oestrogen, desogestrel and gestodene were associated with statistically significantly higher risks of pulmonary embolism but not arterial thromboembolism compared with levonorgestrel. For the same type of progestogen, an oestrogen dose of 20 µg versus 30-40 µg was associated with lower risks of pulmonary embolism, ischaemic stroke, and myocardial infarction.

Instrumental variable analysis as a complementary analysis in studies of adverse effects: venous thromboembolism and second-generation versus third-generation oral contraceptives

PURPOSE

A potentially useful role for instrumental variable (IV) analysis may be as a complementary analysis to assess the presence of confounding when studying adverse drug effects. There has been discussion on whether the observed increased risk of venous thromboembolism (VTE) for third-generation oral contraceptives versus second-generation oral contraceptives could be (partially) attributed to confounding. We investigated how prescribing preference IV estimates compare with conventional estimates.

METHODS

Women in the Clinical Practice Research Database who started a second-generation or third-generation oral contraceptive from 1989 to 2013 were included. Ordinary least squares and two-stage least squares regression were used to estimate risk differences in VTE. Cox regression and IV for Cox proportional hazards regression were used to calculate hazard ratios (HR). The instrument used was the proportion of prescriptions for third-generation oral contraceptives by the general practitioner in the year preceding the current prescription.

RESULTS

All analyses pointed in the direction of an increased VTE risk for third-generation oral contraceptives. The adjusted HR from the conventional Cox regression was 1.62 (95% confidence interval 1.16-2.27) and the fully adjusted HR from the IV Cox regression was 3.45 (95% confidence interval; 0.97-11.7), showing a larger risk and wider confidence intervals in the IV analysis.

CONCLUSIONS

The similarity in direction of results from the IV analyses and conventional analyses suggests that major confounding is unlikely. IV analysis can be a useful complementary analysis to assess the presence of confounding in studies of adverse drug effects in very large databases.

Factor V Leiden

Factor V Leiden (FVLeiden ) is a common hereditary thrombophilia that causes activated protein C (APC) resistance. This review describes many of the most fascinating features of FVLeiden , including background features, mechanisms of hypercoagulability, the founder mutation concept, the "FVLeiden paradox," synergistic interaction with other thrombotic risk factors, the intertwined relationship between FVLeiden and APC resistance testing, and other, uncommon mutations implicated in causing APC resistance. In addition, there are several conditions where laboratory tests for APC resistance and FVLeiden are or can be discrepant, including lupus anticoagulants, anticoagulants such as direct thrombin inhibitors (dabigatran, argatroban, and bivalirudin) and rivaroxaban, as well as pseudohomozygous, pseudo-wildtype, liver transplant, and bone marrow transplant patients. The laboratory test error rate for FVLeiden is also presented.

Family history of venous thromboembolism is a risk factor for venous thromboembolism in combined oral contraceptive users: a nationwide case-control study

BACKGROUND

The aim was to assess the risk of venous thromboembolism (VTE) associated with use of combined oral contraceptives (COCs) in women with a family history of VTE.

METHODS

The study is a Swedish nationwide case-control study based on the Multigeneration register, the Swedish Hospital Discharge Register, the Outpatient Care Register, and the Swedish Prescribed Drug Register. Cases (n = 2,311) were non-pregnant Swedish women aged 15-49 with first VTE diagnoses between January 2006 and December 2010. Five controls without VTE were matched to each case on age and education level. Conditional logistic regression examined the associations with VTE with determination of odds ratio (OR) for first VTE diagnosis. Effect modification was assessed by interaction testing.

RESULTS

Both among controls (14.6 % vs. 4.5 %; p < 0.0001) and cases (27.2 % vs. 8.8 %; p < 0.0001) COC use was more common in women without a family history of VTE compared with women with a family history of VTE. In a multivariate conditional logistic regression model the OR for VTE was 2.53 (95 % CI 2.23-2.87) for COC users and 2.38 (2.09-2.71) for individuals with a family history of VTE. The OR for VTE for COC users with a family history of VTE was 6.02 (5.02-7.22). There was no significant interaction between family history of VTE and COC use (OR 0.92, 0.57-1.46).

CONCLUSIONS

Family history of VTE is a risk factor for VTE in women using COCs. The low prevalence of COC use among women with a family history of VTE suggests that family history of VTE is considered when COCs are prescribed in Sweden. The present study may therefore even underestimate the importance of family history of VTE. The lack of interaction indicates that the risk of COC use in women with family history of VTE is determined by the product of the ORs for family history and COC use.

Hormonal contraception, thrombosis and age

INTRODUCTION

This paper reviews the risk of thrombosis with use of different types of hormonal contraception in women of different ages.

AREAS COVERED

Combined hormonal contraceptives with desogestrel, gestodene, drospirenone or cyproterone acetate (high-risk products) confer a sixfold increased risk of venous thromboembolism as compared with nonusers, and about twice the risk as compared with users of products with norethisterone, levonorgestrel or norgestimate (low-risk products). Transdermal patches and vaginal ring belong to high-risk products. The risk of thrombotic stroke and myocardial infarction is increased 50 - 100% with use of combined products, with little difference in risk between different progestins. Progestin-only products do not confer any increased risk of venous or arterial thrombosis, except for progestin depot, which may double the risk of venous thrombosis.

EXPERT OPINION

First choice in women below 35 years should be a combined low-risk pill, that is, with a second-generation progestin, with the lowest compliable dose of estrogen. Young women with risk factors of thrombosis such as age above 35 years, genetic predispositions, adiposity, polycystic ovary syndrome, diabetes, smoking, hypertension or migraine with aura should not use high-risk products, but should primarily consider progestin-only products, and be careful to use low-risk combined products.

Does the Progestogen Used in Combined Hormonal Contraception Affect Venous Thrombosis Risk?

Combined hormonal contraceptives (CHCs) use a combination of estrogen and progestogen to provide contraception. The most important risk of using CHCs is venous thromboembolism (VTE). It is unclear whether the type of progestogen used in a method augments that risk. Although the evidence supporting an increase in thrombosis risk is not conclusive, neither is the evidence supporting the benefit of newer progestogens in terms of tolerability or continuation. The benefits of CHCs outweigh the risks and the absolute risk of VTE remains small. A balanced discussion of potential risks and benefits of particular CHC formulations is warranted during contraception counseling.

Impact of the sharp changes in the use of contraception in 2013 on the risk of pulmonary embolism in France

BACKGROUND

In late 2012, a national pill crisis led French women to promptly change their behavior regarding contraception, with a significant increase in the use of first-generation and second-generation combined oral contraceptives to the detriment of third-generation and fourth-generation products (C3Gs and C4Gs).

OBJECTIVE

To assess the impact of the sharp changes in 2013 on the rate of women hospitalized for pulmonary embolism in France.

METHODS

All hospitalized pulmonary embolisms in women aged 15-49 years, excluding those occurring during delivery stay, were identified from the French national hospital discharge databases from 2010 to 2013. Hospitalization rates, overall and by age group, were calculated. We compared rates in 2013 with those in 2012, and with mean rates over the preceding 3-year period (2010-2012). Two populations of non-users of contraceptives were used as control groups: men aged 15-49 years, and women aged 50-69 years. The expected reduction in pulmonary embolism incidence, estimated by modeling the number of expected cases based on modifications of combined oral contraceptive exposure, was also considered.

RESULTS

In France, in 2013 as compared with 2012, the pulmonary embolism hospitalization incidence rate in women aged 15-49 years fell by 10.6%, corresponding to a reduction of 322 hospitalizations (95% confidence interval -468 to -156). The expected pulmonary embolism reduction is consistent with the observed reduction in hospitalization incidence rate (-10.2% and -10.6%, respectively). Such a pattern was not observed in the control groups.

CONCLUSIONS

The sharp change in contraception methods, with decreased use of C3Gs and C4Gs, probably played a major role in the reduction in venous thromboembolism morbidity in France.

Contraceptive Vaginal Rings: Do They Pose an Increased Risk of Venous Thromboembolism in Aesthetic Surgery?

Nuvaring (Organon, Kenilworth, NJ) is a vaginal contraception ring inserted by the patient. It was approved by the Food and Drug Administration in 2001 for the prevention of pregnancy. The intent of this paper is to increase the awareness of Nuvaring among plastic surgeons, and to explore the risks associated with its use. We report the cases of two cosmetic surgery patients. These patients developed deep venous thrombosis and pulmonary emboli in the postoperative period while using Nuvaring. The very advantages of the Nuvaring-the ease of use, the avoidance of daily administration, and the insertion and removal of the device by the patient-may lead to the failure of patients to recollect being on a vaginal ring for contraception.

LEVEL OF EVIDENCE

4 Risk.

New insights into the biology of tissue factor pathway inhibitor

Tissue factor pathway inhibitor (TFPI) dampens the initiation of blood coagulation by inhibiting two potent procoagulant complexes, tissue factor-factor VIIa (TF-FVIIa) and early forms of prothrombinase. TFPI isoforms, TFPIα and TFPIβ, result from alternative splicing of mRNA, producing distinct C-terminal ends of the two proteins. Both isoforms inhibit TF-FVIIa, but only TFPIα can inhibit early forms of prothrombinase by binding of its positively charged C-terminus with high affinity to the acidic B-domain exosite of FVa, which is generated upon activation by FXa. TFPIα and TFPIβ are produced in cultured human endothelial cells, while platelets contain only TFPIα. Knowledge of the anticoagulant mechanisms and tissue expression patterns of TFPIα and TFPIβ have improved our understanding of the phenotypes observed in different mouse models of TFPI deficiency, the east Texas bleeding disorder, and the development of pharmaceutical agents that block TFPI function to treat hemophilia.

Deep-vein thrombosis prophylaxis in foot and ankle surgery: what is the current state of practice?

BACKGROUND

When contemplating thromboprophylaxis for patients undergoing elective foot and ankle surgery the potential for complications secondary to venous thromboembolism (VTE) must be balanced against the cost, risk, and effectiveness of prophylactic treatment. The incidence of pulmonary embolism (PE) following foot and ankle surgery is considerably lower than after hip or knee surgery. The purpose of this study was to assess current trends in practice regarding VTE prophylaxis among expert orthopaedic foot and ankle surgeons.

METHODS

An e-mail-based survey of active AOFAS (American Orthopaedic Foot and Ankle Society) committee members was conducted (n = 100). Surgeons were questioned as to their use, type, and duration of thromboprophylaxis following elective ankle fusion surgery. Scenarios included the following: (1) A 50-year-old woman with no risk factors; (2) a 50-year-old woman with a history of PE; and (3) a 35-year-old woman actively using birth control pills (BCPs).

RESULTS

The response rate for the survey was 80% (80/100). Replies regarding the use of thromboprophylaxis were as follows: (1) in the absence of risk factors, 57% of respondents (45/80) answered, "No prophylaxis required"; (2) for the scenario in which the patient had experienced a previous PE, 97.5% of respondents (78/80) answered, "Yes" to prophylaxis use; (3) for the scenario in which the patient was on BCP, 61.3% of respondents (49/80) stated that they would give some type of thromboprophylaxis. The most commonly recommended methods of prophylaxis were aspirin, 49% (24/49), and low-molecular-weight heparin, 47% (23/49). The recommended length of time for thromboprophylaxis varied widely, from 1 day to more than 6 weeks.

CONCLUSION

. There remains wide variation in the practice of deep-vein thrombosis thromboprophylaxis within the foot and ankle community. Because risks for foot and ankle patients differ from those in the well-studied areas of hip and knee, specific guidelines are needed for foot and ankle surgery.

LEVELS OF EVIDENCE

Level V: Expert Opinion.