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

Hormonal contraception and thrombotic risk: a multidisciplinary approach

Heightened publicity about hormonal contraception and thrombosis risk and the publication of new guidelines by the World Health Organization in 2009 and the Centers for Disease Control and Prevention in 2010 addressing this complex issue have led to multidisciplinary discussions on the special issues of adolescents cared for at our pediatric hospital. In this review of the literature and new guidelines, we have outlined our approach to the complex patients referred to our center. The relative risk of thrombosis on combined oral contraception is three- to fivefold, whereas the absolute risk for a healthy adolescent on this therapy is only 0.05% per year. This thrombotic risk is affected by estrogen dose, type of progestin, mechanism of delivery, and length of therapy. Oral progestin-only contraceptives and transdermal estradiol used for hormone replacement carry minimal or no thrombotic risk. Transdermal, vaginal, or intrauterine contraceptives and injectable progestins need further study. A personal history of thrombosis, persistent or inherited thrombophilia, and numerous lifestyle choices also influence thrombotic risk. In this summary of one hospital's approach to hormone therapies and thrombosis risk, we review relative-risk data and discuss the application of absolute risk to individual patient counseling. We outline our approach to challenging patients with a history of thrombosis, known thrombophilia, current anticoagulation, or family history of thrombosis or thrombophilia. Our multidisciplinary group has found that knowledge of the guidelines and individualized management plans have been particularly useful for informing discussions about hormonal and nonhormonal options across varied indications.

The risk of venous thrombosis, including cerebral vein thrombosis, among women with thrombophilia and oral contraceptive use: a meta-analysis

Several small studies have reported an elevated risk of venous thrombosis (VT) with thrombophilia and oral contraceptive (OCP) use. We aimed to summarize the risk of VT among women with thrombophilia and OCP use and to assess the interaction between the 2 factors. We selected 15 studies that assessed the prevalence of OCP use and thrombophilia among reproductive-aged women. Odds ratios (ORs) were calculated for each study and pooled using the random effects model. We found an increased risk of VT among women with OCP use (pooled OR 3.0, 95% confidence interval [CI] 1.9-4.5) and with thrombophilia (pooled OR 4.5, CI 3.4-5.9), respectively. Heterogeneity was significant (I (2) >80%). Women with both thrombophilia and OCP use had a 14-fold risk of VT compared to healthy OCP nonusers (pooled OR 14.25, CI 6.2-32.8). Oral contraceptive use and thrombophilia similarly increase VT risk. Our study confirms an interaction between OCP use and thrombophilia.

Risk of venous thromboembolism and the use of dienogest- and drospirenone-containing oral contraceptives: results from a German case-control study

OBJECTIVE

The primary objective of the study was to clarify whether the use of the oral contraceptive 2 mg dienogest/30 microg ethinylestradiol (DNG/EE) is associated with a higher risk of venous thromboembolism (VTE) than the use of other combined oral low-dose contraceptives (i.e. containing < or =30 microg EE), particularly oral contraceptives containing levonorgestrel (LNG). The secondary objective was to investigate the VTE risk associated with drospirenone/ethinylestradiol (DRSP/EE) in comparison to low-dose LNG/EE.

METHODS

This German community-based, case-control study recruited VTE cases from the primary care sector. Eligible cases were women aged 15-49 years with a VTE between January 2002 and February 2008. Four controls (women without a confirmed or potential VTE before the index date) were matched by age and region to each case. Medical information relevant for the assessment of VTE was abstracted from patient charts. Data on personal characteristics of the patients were collected via self-administered questionnaires. At the end of the study a blinded adjudication of the reported VTE was conducted. Conditional logistic regression techniques were used, adjusting for nine potential confounders, including personal history of VTE, family history of VTE, body mass index, duration of current combined oral contraceptive (COC) use and smoking.

RESULTS

A total of 680 VTE cases and 2720 corresponding controls were analysed. The mean age of cases and controls was - as a result of matching - almost identical (36.1 years). A total of 35, 25, and 60 of the cases had used DNG-, DRSP- and LNG-containing low-dose COCs, respectively, at the time of the VTE diagnosis. The crude odds ratio (OR) for VTE associated with current COC use in comparison to women who had never used a COC before the index date was 1.9 (95% CI 1.5-2.5), the adjusted OR was 2.3 (95% CI 1.7-3.0). The point estimate of the crude OR of DNG/EE vs any other low-dose COCs was 0.9 (95% CI 0.6-1.3), the adjusted OR was 0.9 (95% CI 0.6-1.4). The crude ORs for DNG/EE and DRSP/EE vs low-dose LNG/EE were 1.1 (95% CI 0.7-1.8) and 1.0 (95% CI 0.6-1.6), respectively; the adjusted ORs were 1.1 (95% CI 0.7-1.9) and 1.0 (95% CI 0.6-1.8).

CONCLUSIONS

The study confirms that COC use is associated with an increased risk of VTE. The VTE ORs (adjusted and crude) that compared DNG/EE and DRSP/EE with other low-dose COCs (including LNG/EE) were close to unity and do not indicate a higher risk for users of DNG/EE or DRSP/EE.

Examining the use of oral contraceptives in the management of acne

Combined oral contraceptive pills (cOCPs) are often used in the treatment of acne in females. They are effective, safe, and easy to use in appropriate patients in combination with more conventional acne therapies. This article will briefly address the physiologic rationale for the use of cOCPs in the treatment of acne. It will also review efficacy by examining relevant clinical trials. Safety considerations and the adverse event profile for oral contraceptives will be presented. Finally, practical considerations for prescribing cOCPs will be discussed.

Risk of venous thromboembolism among users of oral contraceptives: a review of two recently published studies

BACKGROUND

Two recent studies, a cohort study from Denmark, and a case-control study from The Netherlands, have reported increased risks of venous thromboembolism (VTE) among users of oral contraceptives (OCs) containing desogestrel, gestodene, drospirenone and cyproterone, relative to the use of levonorgestrel.

CRITIQUE

In the Danish study the comparisons were not valid. (1) VTE risk is highest soon after commencement of OC use, and duration of use was underestimated for levonorgestrel users, but not for drospirenone users; for the remaining compounds duration was only slightly underestimated. The underestimation for levonorgestrel resulted in systematic overestimation of the relative risks for the compared OCs. (2) Duration was also incorrectly estimated: only the duration of current use, not duration of all episodes of use was relevant to VTE risk. (3) Confounding was not adequately controlled. In The Netherlands study the comparisons were not valid. (1) The relative risk for drospirenone versus levonorgestrel was not statistically significant. (2) Extensive publicity had been given to the risk of VTE among users of desogestrel, gestodene, drospirenone and cyproterone: information bias and detection bias were therefore likely. (3) Inadequate allowance was made for duration of use. (4) The combination of two different control groups, both of them likely to have been biased, into a single category was not valid.

CONCLUSION

The best evidence continues to suggest that the increased risk of VTE in OC users is a class effect, dependent on the estrogen dose and duration of use, and independent of the progestogen used.

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.

Use of oral contraceptives containing gestodene and risk of venous thromboembolism: outlook 10 years after the third-generation "pill scare"

BACKGROUND

This study investigated whether gestodene-containing oral contraceptives (OCs) carry a higher risk of venous thromboembolism (VTE) than OCs containing progestins other than desogestrel and gestodene. The study was conducted based on the hypothesis that the biases and confounding factors that were present initially after the introduction of new so-called "third-generation" OCs (i.e., those containing desogestrel and gestodene) in the 1990s, which likely contributed to the alleged increased risk of VTE, may have vanished after 10 years.

STUDY DESIGN

This was a matched case-control study using data identified for women (aged 15-49 years) with suspected or diagnosed VTE (deep vein thrombosis or pulmonary embolism) that occurred between January 2002 and February 2006 in Austria. All VTE cases were validated by an attending/relevant physician(s), a detailed review of medical records and patient-completed questionnaires. Data were analyzed using an unconditional logistic regression model with adjustment for relevant confounders.

RESULTS

Overall, 451 VTE cases and 1,920 controls without VTE were identified. The adjusted odds ratios for confirmed VTE with OC use versus nonuse were: 3.39 (95% CI 2.36-4.87) for OCs containing gestodene and 3.14 (2.1-4.47) for OCs containing progestins other than desogestrel and gestodene. Adjusted odds ratios for a head-to-head comparison of OCs containing gestodene versus OCs containing progestins other than desogestrel and gestodene were: 0.99 (0.68-1.45) for all cases; 1.01 (0.69-1.47) for confirmed cases and 1.11 (0.73-1.69) for confirmed and idiopathic VTE cases, respectively.

CONCLUSION

The risk of VTE is not elevated in users of gestodene-containing OCs relative to users of OCs containing progestins other than desogestrel and gestodene. Our study supports the view that (i) the majority of previous results may be explained by differences in the user populations of so-called "third-generation" OCs (containing desogestrel and gestodene) and "second-generation" OCs (containing progestins other than desogestrel and gestodene) that were present shortly after market introduction of gestodene-containing OCs and that (ii) these differences seem to have disappeared over time.

Polymorphisms in exons 6 and 7 of the ABO locus and their association with venous thrombosis in young Brazilian patients

The A1 and B alleles of the ABO blood system have been associated with high levels of both factor VIII and von Willebrand factor and with a predisposition to venous thromboembolism (VTE). In this study, genotypes of the ABO system were determined by PCR-restriction fragment length polymorphism for 148 young VTE Brazilian patients and 233 unrelated control individuals. The blood group O was more frequent among the controls [odds ratio (OR), 0.21; 95% confidence interval (CI), 0.13-0.34; P = 0.000) and groups A and B (OR, 2.24; 95%, CI, 1.46-3.42; P = 0.000 and OR, 2.52; 95% CI, 1.42-4.48; P = 0.002, respectively) among patients. The patients' group was under Hardy-Weinberg equilibrium, whereas the control group was not (P < 0.0051), suggesting that natural selection might be acting in favor of carriers of the O blood group. When the allelic frequencies were compared through multivariate logistic regression analysis for adjustments of covariates, the alleles A1 (OR, 1.69; 95% CI, 1.17-2.45; P = 0.006), A2 (OR, 2.19; 95% CI, 1.24-3.87; P = 0.010), and B (OR, 2.65; 95% CI, 1.64-4.26; P = 0.000) were independently associated with VTE and may represent important risk factors to the development of VTE among young Brazilian patients. Thus, the inclusion of ABO blood group determination may be helpful to discriminate individuals with high risk for VTE allowing target intervention as well as to manage VTE in young patients.

International Active Surveillance Study of Women Taking Oral Contraceptives (INAS-OC Study)

Background

A 24-day regimen of contraceptive doses of drospirenone and ethinylestradiol (DRSP/EE 24d) was recently launched. This regimen has properties which may be beneficial for certain user populations (e.g., women suffering from premenstrual dysphoric disorder or acne). However, it is unknown whether this extended regimen has an impact on the cardiovascular risk associated with the use of oral contraceptives (OCs). The INternational Active Surveillance study of women taking Oral Contraceptives (INAS-OC) is designed to investigate the short- and long-term safety of the new regimen in a population which is representative for the typical user of oral contraceptives.

Methods/Design

A large, prospective, controlled, non-interventional, long-term cohort study with active surveillance of the study participants has been chosen to ensure reliable and valid results. More than 2,000 gynecologists in the US and 5 European countries (Austria, Germany, Italy, Poland, and Sweden) will recruit more than 80,000 OC users. The two to five year follow-up of these women will result in at least 220,000 documented women-years.

The main clinical outcomes of interest for the follow-up are deep venous thrombosis, pulmonary embolism, acute myocardial infarction and cerebrovascular accidents. Secondary objectives are general safety, effectiveness and drug utilization pattern of DRSP/EE 24d, return to fertility after stop of OC use, as well as the baseline risk for users of individual OC formulations.

Because of the non-interference character of this study, potential participants (first-time users or switchers) are informed about the study only after the decision regarding prescription of a new OC. There are no specific medical inclusion or exclusion criteria. Study participation is voluntary and a written informed consent is required. After the baseline questionnaire, follow-up questionnaires will be mailed to the participants every 6 months for up to 5 years after baseline. Self-reported serious adverse events will be validated by contacting the relevant physician and by reviewing relevant source documents. At the end of the study an independent blinded adjudication of relevant clinical outcomes will be conducted.

Meanwhile, this study has received ethical approval from the Western Institutional Review Board (USA) and the Medical Association in Berlin (Germany).

Discussion

The feasibility of the study is considered to be very high because of its similar design to the EURAS-OC study. All relevant methodological and logistical features of the study were successfully tested in the EURAS study.

The chosen design minimizes the impact of referral and misclassification bias, healthy user effect and loss to follow-up. Overall, it is expected that the study design is robust enough to interpret hazard ratios of 1.5 or higher.

Deciphering the molecular basis of venous thromboembolism: where are we and where should we go?

Venous thromboembolism (VTE) is a frequent disease that has a major genetic component of risk. However, known identified genetic risk factors account for <30% of idiopathic (without any environmental origin) VTE cases. This article aims to review the lessons learnt during recent decades in the field of the genetics of VTE, describe the present state-of-art methods and discuss promising themes for finding new susceptibility loci.

Hormonal contraception and risk of venous thromboembolism: national follow-up study

OBJECTIVE

To assess the risk of venous thrombosis in current users of different types of hormonal contraception, focusing on regimen, oestrogen dose, type of progestogen, and route of administration.

DESIGN

National cohort study.

SETTING

Denmark, 1995-2005.

PARTICIPANTS

Danish women aged 15-49 with no history of cardiovascular or malignant disease.

MAIN OUTCOME MEASURES

Adjusted rate ratios for all first time deep venous thrombosis, portal thrombosis, thrombosis of caval vein, thrombosis of renal vein, unspecified deep vein thrombosis, and pulmonary embolism during the study period.

RESULTS

10.4 million woman years were recorded, 3.3 million woman years in receipt of oral contraceptives. In total, 4213 venous thrombotic events were observed, 2045 in current users of oral contraceptives. The overall absolute risk of venous thrombosis per 10 000 woman years in non-users of oral contraceptives was 3.01 and in current users was 6.29. Compared with non-users of combined oral contraceptives the rate ratio of venous thrombembolism in current users decreased with duration of use (<1 year 4.17, 95% confidence interval 3.73 to 4.66, 1-4 years 2.98, 2.73 to 3.26, and >4 years 2.76, 2.53 to 3.02; P<0.001) and with decreasing dose of oestrogen. Compared with oral contraceptives containing levonorgestrel and with the same dose of oestrogen and length of use, the rate ratio for oral contraceptives with norethisterone was 0.98 (0.71 to 1.37), with norgestimate 1.19 (0.96 to 1.47), with desogestrel 1.82 (1.49 to 2.22), with gestodene 1.86 (1.59 to 2.18), with drospirenone 1.64 (1.27 to 2.10), and with cyproterone 1.88 (1.47 to 2.42). Compared with non-users of oral contraceptives, the rate ratio for venous thromboembolism in users of progestogen only oral contraceptives with levonorgestrel or norethisterone was 0.59 (0.33 to 1.03) or with 75 mug desogestrel was 1.12 (0.36 to 3.49), and for hormone releasing intrauterine devices was 0.90 (0.64 to 1.26).

CONCLUSION

The risk of venous thrombosis in current users of combined oral contraceptives decreases with duration of use and decreasing oestrogen dose. For the same dose of oestrogen and the same length of use, oral contraceptives with desogestrel, gestodene, or drospirenone were associated with a significantly higher risk of venous thrombosis than oral contraceptives with levonorgestrel. Progestogen only pills and hormone releasing intrauterine devices were not associated with any increased risk of venous thrombosis.

The venous thrombotic risk of oral contraceptives, effects of oestrogen dose and progestogen type: results of the MEGA case-control study

OBJECTIVE

To assess the thrombotic risk associated with oral contraceptive use with a focus on dose of oestrogen and type of progestogen of oral contraceptives available in the Netherlands.

DESIGN

Population based case-control study.

SETTING

Six participating anticoagulation clinics in the Netherlands (Amersfoort, Amsterdam, The Hague, Leiden, Rotterdam, and Utrecht).

PARTICIPANTS

Premenopausal women <50 years old who were not pregnant, not within four weeks postpartum, and not using a hormone excreting intrauterine device or depot contraceptive. Analysis included 1524 patients and 1760 controls.

MAIN OUTCOME MEASURES

First objectively diagnosed episodes of deep venous thrombosis of the leg or pulmonary embolism. Odds ratios calculated by cross-tabulation with a 95% confidence interval according to Woolf's method; adjusted odds ratios estimated by unconditional logistic regression, standard errors derived from the model.

RESULTS

Currently available oral contraceptives increased the risk of venous thrombosis fivefold compared with non-use (odds ratio 5.0, 95% CI 4.2 to 5.8). The risk clearly differed by type of progestogen and dose of oestrogen. The use of oral contraceptives containing levonorgestrel was associated with an almost fourfold increased risk of venous thrombosis (odds ratio 3.6, 2.9 to 4.6) relative to non-users, whereas the risk of venous thrombosis compared with non-use was increased 5.6-fold for gestodene (5.6, 3.7 to 8.4), 7.3-fold for desogestrel (7.3, 5.3 to 10.0), 6.8-fold for cyproterone acetate (6.8, 4.7 to 10.0), and 6.3-fold for drospirenone (6.3, 2.9 to 13.7). The risk of venous thrombosis was positively associated with oestrogen dose. We confirmed a high risk of venous thrombosis during the first months of oral contraceptive use irrespective of the type of oral contraceptives.

CONCLUSIONS

Currently available oral contraceptives still have a major impact on thrombosis occurrence and many women do not use the safest brands with regard to risk of venous thrombosis.

Combined hormonal contraception and venous thromboembolism

This review provides an update of knowledge regarding venous thromboembolism (VTE) and combined hormonal contraceptives (CHCs) in the light of new progestins and new administration routes for CHCs. Practical recommendations are also offered. The association between the use of combined oral contraceptives (COCs) and an increased risk of VTE has been known about for many years, it being related mainly to the dose of oestrogen; however, recent research has also shown the influence of the type of progestin. When compared to COCs containing levonorgestrel or norethisterone, those containing desogestrel or gestodene present a two-fold greater risk of VTE; for COCs containing cyproterone acetate, the risk is four-fold greater, while there are no or insufficient data for those containing norgestimate, chlormadinone acetate or drospirenone. With regard to the contraceptive patch, the available data suggest that the risk of VTE is similar to that observed with COCs. There are no data concerning vaginal rings. The greatest risk of COC-associated VTE occurs during the first year of use, thus suggesting the existence of a predisposing condition, such as being a carrier of a thrombogenic mutation with which the COCs would exert a synergistic effect. Routine screening for such conditions is not justified. Changes in haemostatic variables produced by COCs, for example, acquired resistance to protein C, could be linked to VTE, although it has yet to be demonstrated that such alterations are related to a clinical risk of VTE among COC users. At present there are no laboratory tests able to detect an increased risk of VTE in asymptomatic women. The key procedures in terms of ensuring the safe use of this contraceptive method are a full clinical, personal and family history, in order to evaluate risk factors for VTE and cardiovascular disease, along with the recording of blood pressure and body mass index prior to the prescription of COCs.

[Drugs and venous thromboembolism]

Among the many factors likely to favour the occurrence of venous thromboembolism (VTE), exposure to certain drugs has to be taken into account. Although hormone treatments, oral contraception and hormone replacement therapy (HRT) for menopause have been studied, these are not the only drugs associated with an increased risk of VTE. The antipsychotics have also been incriminated in the occurrence of venous thromboembolism. The association of thalidomide and dexamethasone, used in the treatment of multiple myeloma, is responsible for a major increase in the risk of VTE. The physiopathological mechanisms accounting for the possible prothrombotic effect of most of these drugs is still not fully understood. Further observational and interventional clinical studies should provide a better understanding of VTE, potentially associated with drugs. However, certain drugs may be associated with a reduced risk of VTE. Although several studies indicate that aspirin and statins may favourably influence the risk of VTE, it is still not possible to draw up any practical recommendations.

The effects of two monophasic oral contraceptives containing 30 mcg of ethinyl estradiol and either 2 mg of chlormadinone acetate or 0.15 mg of desogestrel on lipid, hormone and metabolic parameters

BACKGROUND

This study was conducted to compare the effects of two monophasic oral contraceptives (OCs) containing ethinyl estradiol (EE) 30 mcg+either chlormadinone acetate (CMA) 2 mg (Belara) or 0.15 mg desogestrel (Marvelon) on lipid, hormone and other relevant metabolic parameters.

STUDY DESIGN

Markers of lipid and carbohydrate metabolism, and reproductive hormone levels, were measured in 45 subjects randomly assigned to 6 months of treatment with one of the two OCs. The cortisol response to adrenocorticotrophic hormone (ACTH) stimulation was also evaluated.

RESULTS

In both treatment groups, triglycerides, high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo) AI and Apo AII levels increased; low-density lipoprotein cholesterol (LDL-C) and the LDL-C/HDL-C ratio decreased; and total cholesterol and lipoprotein(a) were unchanged during treatment. Effects on HDL-C, Apo AI, LDL-C and the LDL-C/HDL-C ratio were more evident in the EE 30 mcg+CMA 2 mg group. Follicle-stimulating hormone, luteinizing hormone and androgen levels decreased and sex hormone-binding globulin levels increased in both groups. Both OCs increased basal cortisol levels and cortisol response to ACTH. Oral contraceptive did not have a clinically significant impact on carbohydrate metabolism.

CONCLUSIONS

Both low-dose monophasic OCs had comparable effects on lipid, hormone and metabolic parameters during six cycles of treatment in healthy female subjects. There was some evidence of a beneficial effect on atherogenic cardiovascular risk markers, which was slightly more pronounced with EE 30 mcg+CMA 2 mg.

Venous thromboembolism in women

Abstract

The risk of venous thromboembolism (VTE) varies throughout a woman’s life and is associated primarily with underlying hormonal exposure. Alteration in hemostatic mechanisms, including resistance to activated protein C, may explain this altered risk. Initially, development of VTE with the use of contraception in young adulthood may reveal inherited thrombophilia. Pregnancy, and particularly the post-partum period, likely confer the greatest risk of VTE, but the absolute risk is small. Guidelines for prevention of VTE during pregnancy are based on personal or family history of VTE, and known inherited thrombophilia. Use of hormone replacement therapy later in life is associated with increased risk of VTE, and may be safest if given as an estrogen-only preparation to young postmenopausal women for less than 5 years. Universal screening for thrombophilia prior to pregnancy or initiating hormonal therapy is not recommended; however, selected testing in high-risk groups may be warranted. The lack of firm recommendations for the prevention of VTE in women highlights the need for future investigation aimed at identifying high-risk groups and evaluating the efficacy of prophylactic measures.

Trends in prescribing patterns of hormonal contraceptives for adolescents

BACKGROUND

Little is known regarding how prescribing patterns of hormonal contraceptives to adolescents in the United States have changed over time as new formulations become available and knowledge of thrombosis risk increases. Desogestrel and high-dose estrogen-containing formulations have been associated with a higher risk of thrombosis than other methods.

STUDY DESIGN

We used the National Ambulatory Medical Care/National Hospital Ambulatory Medical Care surveys to describe trends in contraception prescriptions for 11- to 21-year-old females between 1993 and 2004.

RESULTS

The majority of prescriptions arose from obstetrics/gynecology clinics. The proportion of desogestrel-containing prescriptions was approximately 10% throughout the study period. Ortho Evra (transdermal norelgestromin, ethinyl estradiol) and Yasmin (oral drospirenone, ethinyl estradiol) accounted for a steadily increasing proportion of prescriptions.

CONCLUSION

With regard to contraception and thrombosis risk, a significant minority of adolescents are prescribed desogestrel-containing contraceptives, and a greater number are exposed to higher levels of estrogen from transdermal contraception. Future studies are needed to evaluate the absolute risk of thrombosis in adolescents using these formulations so clinicians have accurate safety information when prescribing to this unique population.

Hormone therapy and thromboembolic disease

PURPOSE OF REVIEW

Hormone therapy increases the risk of venous thromboembolism (VTE). To reduce this risk, changes in dosage, composition and route of administration have been made over the years. This review provides a summary of the available evidence and an update on the most recent findings on the issue.

RECENT FINDINGS

Contraceptives containing third-generation progestagens confer a higher risk of VTE than second-generation compounds. Little data are available on preparations containing less than 30 micarog of estrogen, new progestagens or levonorgestrel-releasing intrauterine devices. Hormone replacement therapy increases the risk of VTE by 2 to 3-fold. Transdermal administration may be less thrombogenic than oral administration, while different estrogens and progestagens may carry a different risk. VTE risk is further increased in carriers of inherited thrombophilia. Despite a similar increase in relative risk of thrombosis associated with hormone therapy, absolute risk is lower in fertile women and higher in postmenopausal ones. Universal screening for thrombophilia before prescribing hormone replacement therapy might be cost-effective.

SUMMARY

Careful evaluation of individual risk factor is warranted before prescribing hormone therapy. Further investigations are needed to establish whether or not newer compounds are safer than older ones with respect to the risk of thrombosis.

Upper extremity deep vein thrombosis after suspension of progesterone-only oral treatment

The intake of steroid hormone contraceptives is a strong and independent risk factor for venous thromboembolism. Several studies have assessed an increased risk of venous thromboembolism in women using oral contraceptives who are carriers of the G20210A mutation in the prothrombin gene. Most trials evaluating the thrombotic risk of oral contraceptives are based on combined oral preparations, but only a few focus on progestogen-only oral preparations. Results from such studies are conflicting and globally assess the thrombotic risk, ranging from modest to slightly increased. Furthermore, little is known about the relationship between the C677T mutation in the methylenetetrahydrofolate reductase gene and the progestogen-based preparations. Herewith we report the case of a 49-year-old woman with a complex genetic thrombosis risk factor who had taken oral progesterone for 15 months without any complication, but then experienced severe left upper extremity deep vein thrombosis 2 months after the drug suspension.

Venous thrombosis in the elderly

While the overall incidence of venous thrombosis is 1-2 per 1000 per year, it is close to 1% per year in the very old. The case-fatality rate of thrombosis is high in the elderly, particularly among those with cancer. The risk of major hemorrhage during anticoagulant treatment is also strongly age-dependent, contributing to the vulnerability of the old patient with thrombosis. From this perspective it is surprising that far fewer studies into the etiology and treatment of venous thrombosis have focused on the elderly than on young and middle-aged patients. In this review we discuss that, while environmental risk factors, such as immobilization and cancer, are important causes of thrombosis in the elderly, abnormalities of the coagulation system are equally, or even more, important than in young individuals. In addition to a review of the literature, new data are presented from the MEGA-study. Thrombosis in the elderly should be a focus of future studies.

A case of Budd–Chiari syndrome with Behcet’s disease and oral contraceptive usage

We present a case of Budd-Chiari syndrome (BCS) having two risk factors, Behcet's disease (BD) and oral contraceptive (OC) usage. A 33-year-old woman with BD was admitted to the Emergency Unit with nausea, vomiting, abdominal pain, abdominal distention, and confusion started 12 days ago before admission. Since the patient was in a shock state, she was taken to the Intensive Care Unit (ICU) with the suspicion of abdomen-originated sepsis. Abdominal ultrasound showed massive hepatosplenomegaly and moderate ascites. Abdominal MRI revealed an inferior vena cava (IVC) obstruction starting above the renal veins and diffuse thrombosis of the right and medial hepatic veins. An extensive thrombosis of the IVC and the hepatic veins (BCS) which led to shock was diagnosed. In addition to BD, the unnotified OC usage for a year by the patient without her doctor's knowledge was recognized as possible precipitating factor of BCS. Pulse methylprenisolone was started for three consecutive days to treat active BD-induced vasculitis. IVC digital subtraction angiography (DSA) showed occlusion of the IVC below the hepatic veins with extensive collateral circulation originating at the occlusion level suggesting that obliteration had a subacute or chronic course. Since intralesional thrombolytic therapy failed, the patient was transferred to a liver transplantation center. While waiting for an appropriate donor, the patient died due to hepatic failure. Since BCS is mortal and deemed multi-factorial, every patient with a thrombotic risk factor such as BD should be questioned for other possible causes of thrombosis.

Sex hormones and thrombosis

There is compelling evidence that use of oral formulations of female hormone replacement and of the combined oral contraceptive induces a prothrombotic state. This translates to an increased thrombotic risk. Within the individual, the absolute risk is determined by the interaction between that induced by hormone use and heritable and acquired risk factors for thrombosis. Knowledge of the accumulating epidemiologic and clinical trial-derived data on this topic is essential for the delivery of evidence-based counseling in the clinical environment and is the subject of this review.

The safety of a drospirenone-containing oral contraceptive: final results from the European Active Surveillance study on Oral Contraceptives based on 142,475 women-years of observation

OBJECTIVES

The study was conducted to compare risks of adverse cardiovascular and other events associated with the use of drospirenone (DRSP)-containing oral contraceptives (OCs) and other OCs.

METHODS AND MATERIALS

The European Active Surveillance study (EURAS) was a multinational, prospective, noninterventional cohort study of new users of DRSP, levonorgestrel (LNG) and other progestin-containing OCs. Semiannual follow-up was based on mailed questionnaires, with additional follow-up procedures when needed.

RESULTS

Overall, 58,674 women were followed for 142,475 women-years of observation. Loss to follow-up was 2.4%. Serious adverse and fatal events were rare, and rate ratios were close to unity (1.0). Cox regression analysis of cardiovascular outcomes yielded hazard ratios for DRSP-containing vs. LNG-containing and other OCs of 1.0 and 0.8 (upper 95% confidence limits, 1.8 and 1.3) for venous, and 0.3 and 0.3 (upper 95% confidence limits, 1.2 and 1.5) for arterial thromboembolism, respectively.

CONCLUSIONS

Risks of adverse cardiovascular and other serious events in users of a DRSP-containing OC are similar to those associated with the use of other OCs.

Increased Factor V Leiden frequency is associated with venous thrombotic events among young Brazilian patients

INTRODUCTION

Of the inherited thrombophilias, the Factor V Leiden (FVL) and the prothrombin mutant (FII G20210A) are associated with increased risk of venous thromboembolism (VTE). The C677T mutation of the methylenetetrahydrofolate reductase gene, which may lead to hyperhomocysteinemia, is also considered a risk factor for VTE in some studies. However, the frequency of these genetic risk factors may vary significantly among different populations.

MATERIAL AND METHODS

The FVL, FII G20210A and C677T mutations were investigated by PCR-RFLP in 275 young VTE Brazilian patients as well as in 324 biologically unrelated individuals selected to compose the control group.

RESULTS

The C677T mutation in the MTHFR gene was detected in 135 (49.1%) patients, of which 117 (42.5%) were identified as heterozygous and 18 (6.5%) as homozygous. The G20210A mutation was detected in 14 (5.1%) patients in heterozygosis. In both cases, no significant difference was observed when these results were compared to the frequencies observed in the control group. FVL was detected in heterozygosis in 19 (6.9%) patients, corresponding to a significantly increased frequency when compared to that observed for the control group (1.2%) (OR 5.9; 95% CI 2.08-16.79; p < 0.001).

CONCLUSIONS

The data indicated that FVL is significantly associated with VTE among young Brazilian patients, but also supported previous evidence that VTE is a multi-factorial disease, resulting from the interaction of genetic and acquired risk factors.

A comprehensive analysis of 12 thrombophilic mutations and related parameters in patients with inflammatory bowel disease: data from Turkey

BACKGROUND

Possible association of inflammatory bowel disease (IBD) with the most common inherited prothrombotic conditions has been the focus of many investigations. Advance in modern molecular biology is expanding the thrombophilia evaluation steadily. We tried to put forward a comprehensive thrombophilic profile in IBD and to see the probable role of this profile in pathogenesis.

METHODS

A total of 60 adults (33 patients and 27 healthy controls) were included. We used the CVD-StripAssay which is based on the reverse-hybridization principle to identify a total of 12 thrombophilic gene mutations: Factor V R506Q, Factor V H1299R, prothrombin G20210A, Factor XIII V34L, beta-Fibrinogen-455 G-A, PAI-1 4G/5G, platelet GPIIIa L33P, MTHFR C677T, MTHFR A1298C, ACE I/D, Apo B R3500Q and Apo E2/E3/E4, respectively. Besides, we evaluated many related blood parameters such as protein C, protein S, AT-III, IL-6, TNF-alpha, Apo-A1, Apo-B100, homocysteine (tHcy) etc. using commercially available assays.

RESULTS

The frequencies of genetic polymorphisms were found to be statistically insignificant among patients and controls, except for three: Beta-Fibrinogen-455G-A, MTHFR A1298C and ACE-I/D. Two patients with a history of deep venous thrombosis had more than one polymorphism. Patients with MTHFR C677T and MTHFR A1298C gene mutations had a similar mean tHcy levels with controls. Patients with Apolipoprotein B R3500Q and Apolipoprotein E4 gene mutations had similar mean LDL-cholesterol levels. Mean total cholesterol and triglyceride levels were similar in patients and controls of Apo E2, E3, E4 alleles.

CONCLUSION

Predominantly, the presence of genetic mutations that predispose to hypercoagulable states does not appear to be in correlation with IBD. There was a statistical difference between the proportions of the mutated allele frequencies of Beta-Fibrinogen-455G-A, MTHFR A1298C and ACE-I/D in IBD.

Recent advances in the treatment of thromboembolic diseases: Venous thromboembolism

Venous thromboembolic diseases are the major concern of rising cost of healthcare and are commonest health problem across the globe. Both genetic and acquired risk factors are believed to be strongly linked with these diseases. Commonly encountered problems to the therapy include dose fixing and routine monitoring, yet some serious problems of bleeding also necessitate the immediate need to develop new agents. The review is primarily concerned with the new developments in the treatment of thromboembolic diseases. Therapeutic applications of anticoagulants, antiplatelets, and thrombolytics have been discussed in enough detail.

Conjugated Equine Estrogen, Esterified Estrogen, Prothrombotic Variants, and the Risk of Venous Thrombosis in Postmenopausal Women

Background— Joint exposure to oral conjugated equine estrogen (CEE) and prothrombotic genetic variants factor II G20210A or factor V G1601A (Leiden) increase venous thrombotic risk 6- to 16-fold in postmenopausal women. Esterified estrogen (EE), an alternative estrogenic compound, appears not to be associated with increased risk and nothing is known about the joint risk with prothrombotic genetic variants.

Methods and Results— We conducted a population-based, case-control study among postmenopausal women within a health maintenance organization. Subjects included 328 cases who sustained a first venous thrombosis and 1591 controls. Current hormone use was defined using electronic pharmacy records and variants FII G20210A and FV Leiden were genotyped using blood samples. FII and FV Leiden variants were associated with 2.1-fold and 3.7-fold increases in venous thrombotic risk, respectively. Overall, CEE use was associated with a 2.5-fold increase in risk compared with no hormone use, whereas EE use was not associated with a statistically increased risk. Compared with no hormone use and no variant, joint exposure to CEE and either prothrombotic variant was associated with an odds ratio (OR) of 9.1 (95% CI: 4.5 to 18.2), whereas joint exposure to EE and either variant was associated with an OR of 2.1 (0.6 to 6.8). When analyses were restricted to hormone users with either variant, CEE use was associated with an OR of 5.3 (1.3 to 21.7) compared with EE use.

Conclusions— These findings need replication and suggest EE use is associated with less risk than CEE use especially among 5% to 10% of women who are carriers of a prothrombotic variant.

Progestins overcome inhibition of platelet aggregation by endothelial cells by down‐regulating endothelial NO synthase via glucocorticoid receptors

Hormone replacement therapy with estroprogestin preparations is associated with an increased risk of venous and arterial thromboembolic events in postmenopausal women. This study examined whether progestins affect the formation of NO in endothelial cells, and, if so, to determine the underlying mechanism. Experiments were performed with human umbilical vein endothelial cells. Endothelial nitric oxide synthase (eNOS) expression was assessed by real-time polymerase chain reaction (PCR) and Western blot analysis, NO formation by electron spin resonance spectroscopy, nuclear translocation of the glucocorticoid receptor by immunofluorescence microscopy, and platelet aggregation by an aggregometer. Medroxyprogesterone acetate (MPA) and progesterone markedly decreased the eNOS mRNA and protein levels, whereas levonorgestrel and nomegestrol acetate had only small effects. This effect was associated with a decreased NO formation leading to a reduced ability of endothelial cells to prevent platelet aggregation and was prevented by knockdown of the glucocorticoid receptor using siRNA. MPA and progesterone, but not levonorgestrel and nomegestrol acetate, caused nuclear translocation of the glucocorticoid receptor. The present findings indicate that certain progestins, including MPA, reduce the antiaggregatory effect of endothelial cells by decreasing the expression of eNOS and the formation of NO in endothelial cells, an effect that is mediated via activation of glucocorticoid receptors.

Hormonal contraception in adolescents: special considerations

With the rates of unintended pregnancies in teenagers remaining high, it is crucial to present adolescents with all of the contraceptive options available to them. While barrier methods, for example, male condoms, are easily accessible and do not have adverse effects, their use must be consistent and correct with each act of intercourse. Hormonal contraception affords much better efficacy in preventing pregnancy when used with full compliance. Oral contraceptives are a popular method of contraception among adolescents and offer many non-contraceptive benefits along with the prevention of pregnancy. They have very few significant adverse effects, which are outweighed by the significant morbidity associated with teenage pregnancies, and can be used by most adolescent females. However, their minor bothersome effects do contribute to the high discontinuation rates seen. In addition, many girls find it difficult to remember to take a pill every day, leading to higher failure rates in teenagers than in adult women. The advent of long-acting, progestogen (progestin)-only methods, such as injectables and implantables, has been generally accepted by adolescents and these methods have proven to be more efficacious by avoiding the need for daily compliance. However, progestogen-only methods cause irregular bleeding and amenorrhea, which is not acceptable to many teenagers. In addition, the most widely used implant was taken off the market a few years ago and newer forms are not yet widely accessible. Other novel methods are currently available, including the transdermal patch and the vaginal ring. Both are combinations of estrogen and progestogen and have similar efficacy and adverse effect profiles to oral contraceptives. Their use may be associated with greater compliance by adolescents because they also do not require adherence to a daily regimen. However, there may be some drawbacks with these newer methods, for example, visibility of the patch and difficulty with insertion of the vaginal ring. When regular contraceptive modalities fail, emergency contraception is available. Choices include combination oral contraceptives, progestogen-only pills, mifepristone, or placement of a copper-releasing intrauterine device. These methods can be very useful for preventing pregnancy in adolescents as long as adolescents are aware of their existence and have easy access to them.

Exogenous Sex Hormones and Thrombophilia

Worldwide, hundreds of millions of women use exogenous estrogens in contraceptives or for postmenopausal hormone replacement. Exogenous estrogens increase the risk for venous and arterial thrombosis. This article reviews the use of exogenous sex hormones in women with thrombophilia.

Genome-based biomarkers for adverse drug effects, patient enrichment and prediction of drug response, and their incorporation into clinical trial design

Classic examples of pharmacogenomic biomarkers for drug efficacy include genetic variation in the drug target (including its expression level) and drug metabolizing enzymes (DMEs). Recent US FDA approvals of tests for cytochrome P450 2D6/2C9 and uridine diphosphate glucuronsyltransferase (UGT)1A1 have given regulatory endorsement to biomarkers that can improve drug safety by identifying individuals at risk for drug toxicity. Markers that predict risk for disease can identify patients who will have a greater than average benefit from therapy. This creates a new opportunity to enrich clinical trials with patients who are likely to have more events and to achieve earlier drug approval. Markers that predict for risk of cardiovascular, thrombotic and liver diseases may also identify a subset of individuals at substantially elevated risk for adverse drug effects. The adaptive clinical trial design provides a mechanism for incorporating genomic information during clinical trials, while providing sufficient time for diagnostic product development and co-registration with a new drug application.