Extended Treatment Of Venous Thromboembolism Research Articles

D-dimer and risk of venous thromboembolism recurrence: Comparison of two studies with similar designs but different laboratory and clinical results

BackgroundD-dimer testing may help deciding the duration of anticoagulation in subjects at high risk of venous thromboembolism (VTE) recurrence. Two management studies on this issue have been published (DULCIS in 2014 and APIDULCIS in 2022). They had similar designs but had important different results. Aim of this article is to compare their results. MethodsBoth studies were finalized to extend anticoagulation [with vitamin K anticoagulants (VKAs) in DULCIS or apixaban 2.5 mg BID (kindly provided by BMS-Pfizer Collaboration) in APIDULCIS] only in patients with positive D-dimer results. ResultsMore D-dimer assays resulted positive in APIDULCIS than in DULCIS (61.1 % vs 47.7 %, respectively; p < 0.0001). While only 4 (0.5 %) refused low dose apixaban in APIDULCIS, the 22.6 % of patients with positive D-dimer refused to resume VKAs in DULCIS; their rates of recurrence were 187 and 8.8 per 100 person-years, respectively (incidence rate ratio [IRR]: 21.2). The incidence of bleeding was low in those receiving apixaban vs those who resumed VKAs (0.4 vs 2.3 per 100 person-years, respectively; IRR 0.17;). While the recurrence rate was low and similar in the studies in subjects who resumed anticoagulation, it was significantly higher in APIDULCIS than in DULCIS in those who stopped anticoagulation for negative D-dimer (5.6 vs 3.0 per 100 person-years, respectively; IRR 1.9). ConclusionThe low dose Apixaban for extended VTE treatment is effective and safe, and well accepted by patients. Why subjects who stopped anticoagulation for negative D-dimer had a higher recurrence rate in APIDULCIS than in DULCIS remains to be explained.

Primary Care Clinicians' Prescribing Patterns of Reduced-Dose Direct Oral Anticoagulants for Extended-Phase Venous Thromboembolism Treatment.

The direct anticoagulants (DOACs), apixaban and rivaroxaban, are used for extended-phase treatment of venous thromboembolism (VTE) and have labeling for dose reduction for this indication. The objective of this study was to better understand primary care clinician prescribing patterns of apixaban and rivaroxaban for extended-phase anticoagulation. We conducted a 21-question survey targeting members of the American College of Physicians and United States Veterans Administration anticoagulation management services. Survey questions covered prescribing behaviors for dose reduction of apixaban and rivaroxaban for extended VTE treatment, as well as questions related to the respondent's practice setting. We used logistic regression to assess associations between demographics and prescribing behaviors. We used k-means clustering to identify distinct groups of prescribing patterns. Among 227 respondents, most were attending physicians (60%) and one-third (34%) practiced in internal medicine or primary care. Most (59%) indicated they dose-reduced DOACs. Hospitalists (no outpatient care) were least likely to dose-reduce (OR 0.09 [95% CI 0.03-0.22]), as well as early-career clinicians (0.53 [0.30-0.91]). Pharmacists and clinicians who treat over 500 VTE patients annually were most likely to dose reduce (6.4 [2.9-16.3]), (2.9 [1.5-6.0]), respectively. We identified five clusters of dosing behaviors and characterized clinician makeup. Clusters were primarily differentiated by frequency of dose reduction, DOAC preference, and temporary re-escalation of doses. We identified clinician characteristics that are associated with dose-reduction prescribing behaviors; these analyses provide insight into where targeted interventions, such as protocolization and education, would be most beneficial.

Clinical Outcomes of Direct Oral Anticoagulants vs Warfarin for Extended Treatment of Venous Thromboembolism

Extending the duration of oral anticoagulation for venous thromboembolism (VTE) beyond the initial 3 to 6 months of treatment is often recommended, but it is not clear whether clinical outcomes differ when using direct oral anticoagulants (DOACs) or warfarin. To compare rates of recurrent VTE, hospitalizations for hemorrhage, and all-cause death among adults prescribed DOACs or warfarin whose anticoagulant treatment was extended beyond 6 months after acute VTE. This cohort study was conducted in 2 integrated health care delivery systems in California with adults aged 18 years or older who received a diagnosis of incident VTE between 2010 and 2018 and completed at least 6 months of oral anticoagulant treatment with DOACs or warfarin. Patients were followed from the end of the initial 6-month treatment period until discontinuation of anticoagulation, occurrence of an outcome event, health plan disenrollment, or end of the study follow-up period (December 31, 2019). Data were obtained from the Kaiser Permanente Virtual Data Warehouse and electronic health records. Data analysis was conducted from March 2022 to January 2023. Dispensed prescriptions of DOACs or warfarin after a 6-month initial treatment for VTE. The primary outcomes were rates per 100 person-years of recurrent VTE, hospitalizations for hemorrhage, and all-cause death. Comparison of DOAC and warfarin outcomes were performed using multivariable Cox proportional hazards regression. A total of 18 495 patients (5477 [29.6%] aged ≥75 years; 8973 women [48.5%]) with VTE who were treated with at least 6 months of anticoagulation were identified, of whom 2134 (11.5%) were receiving DOAC therapy and 16 361 (88.5%) were receiving warfarin therapy. Unadjusted event rates were lower for patients receiving DOAC therapy than warfarin therapy for recurrent VTE (event rate per 100 person-years, 2.92 [95% CI, 2.29-3.54] vs 4.14 [95% CI, 3.90-4.38]), hospitalizations for hemorrhage (event rate per 100 person-years, 1.02 [95% CI, 0.66-1.39] vs 1.81 [95% CI, 1.66-1.97]), and all-cause death (event rate per 100 person-years, 3.79 [95% CI, 3.09-4.49] vs 5.40 [95% CI, 5.13-5.66]). After multivariable adjustment, DOAC treatment was associated with a lower risk of recurrent VTE (adjusted hazard ratio [aHR], 0.66; 95% CI, 0.52-0.82). For patients prescribed DOAC treatment, the risks of hospitalization for hemorrhage (aHR, 0.79; 95% CI, 0.54-1.17) and all-cause death (aHR, 0.96; 95% CI, 0.78-1.19) were not significantly different than those for patients prescribed warfarin treatment. In this cohort study of patients with VTE who continued warfarin or DOAC anticoagulation beyond 6 months, DOAC treatment was associated with a lower risk of recurrent VTE, supporting the use of DOACs for the extended treatment of VTE in terms of clinical outcomes.

The anticoagulation length of therapy and risk of new adverse events in venous thromboembolism (ALTERNATIVE) study: Design and survey results.

The Anticoagulation Length of Therapy and Risk of New Adverse Events In Venous Thromboembolism (ALTERNATIVE) study was designed to compare the benefits and harms of different treatment options for extended treatment of venous thromboembolism (VTE). In this paper, we describe the study cohort, survey data collection, and preliminary results. We identified 39,605 adult patients (age ≥ 18 years) from two large integrated health care delivery systems who were diagnosed with incident VTE and received initial anticoagulation therapy of 3 months or longer. A subset of the cohort (12,737) was invited to participate in a survey. Surveys were completed in English, Spanish or Mandarin via a mailed questionnaire, an online secure web link, or telephone. The survey domains included demographics, personal medical history, anticoagulant treatment history, anticoagulant treatment satisfaction, health-related quality of life and health literacy. A total of 5,017 patients participated in the survey for an overall response rate of 39.4%. The mean (SD) age of the survey respondents was 63.0 (14.5) years and self-reported race was 76.0% White/European, 11.1% Black/African American, and 3.8% Asian/Pacific Islander and 14.0% reported Hispanic ethnicity. Sixty percent of respondents completed the web survey, while 29.0% completed the mail-in paper survey, and 11.0% completed the survey via telephone. The ALTERNATIVE Study will address knowledge gaps by comparing several treatment alternatives for the extended management of VTE so that this information could be used by patients and clinicians to make more informed, patient-centered treatment choices.

Clinical and Safety Outcomes Associated with Extended Treatment of Venous Thromboembolism: A Network Meta-Analysis.

Many anticoagulant strategies are available for the extended treatment of venous thromboembolism, yet little guidance exists regarding which drug is most effective and safe. A network meta-analysis was performed to resolve this uncertainty. We searched the medical literature through June 2022 for randomized controlled trials (RCTs) evaluating the efficacy and safety of anticoagulants for adults with VTE compared with other anticoagulants or a placebo. We identified 13 eligible RCTs in 12 articles. All pooled hazard ratios (HR) and 95% credible intervals (CrI) mentioned below, except that for aspirin, were calculated by comparison with standard-intensity warfarin. Novel oral anticoagulants (NOACs) were not inferior to standard-intensity warfarin in preventing recurrence, and edoxaban was ranked first among the NOACs (HR, 0.99; 95% CrI, 0.70-1.39). All the NOACs, except rivaroxaban, were superior to standard-intensity warfarin in preventing bleeding events. Apixaban was ranked first and was considered to be safer than other NOACs for control of both major bleeding (HR = 0.07, 95% CrI: 0.01-0.37) and clinically relevant non-major bleeding (CRNMB, HR = 0.30, 95% CrI: 0.13-0.67). Edoxaban was ranked second among the NOACs for control of major bleeding (HR = 0.44, 95% CI: 0.21-0.88), and dabigatran was ranked second among the NOACs for control of CRNMB (HR = 0.54, 95% CrI: 0.4-0.73). There existed no statistically significant differences in recurrence between NOACs and standard-intensity warfarin, and NOACs were associated with a lower risk of bleeding events. Edoxaban effectively prevented VTE recurrence and major bleeding, and apixaban was the best anticoagulant for controlling bleeding events.

PO-55: Effectiveness and safety of enoxaparin in the extended treatment of venous thromboembolism in active cancer patients with renal impairment: results from the RIETECAT-RI cohort study

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Comparative efficacy and safety of oral anticoagulants for the treatment of venous thromboembolism in the patients with different renal functions: a systematic review, pairwise and network meta-analysis

ObjectivesTo compare the efficacy and safety of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) and different renal functions.DesignSystematic review containing pairwise and Bayesian network meta-analysis of randomised...

Comparative Effectiveness and Safety of Extended Anticoagulant Therapy Among Medicare Beneficiaries with Venous Thromboembolism

▪Introduction: Approximately 30% of patients with venous thromboembolism (VTE) experience a recurrence within 10 years of the initial event with their recurrence risk peaking during the first 6-12 months. Two large randomized clinical trials AMPLIFY-EXT and PADIS-PE reported that extended treatment with apixaban and warfarin beyond 6 months of initial treatment reduced recurrent VTE without increasing the rate of major bleeding compared to placebo, respectively. Little is known about real-world effectiveness and safety of extended oral anticoagulation beyond 6 months of initial treatment for Medicare beneficiaries with VTE, despite the fact that VTE disproportionately affects the elderly. We assessed the effectiveness and safety of extended use of apixaban and warfarin beyond 6 months of initial treatment for prevention of recurrent VTE and adverse major bleeding events among Medicare beneficiaries with newly diagnosed VTE.Methods: A retrospective cohort study using 2014-2018 Medicare data (5% samples in 2014-2016 and 15% samples of Medicare beneficiaries in 2017-2018) was conducted for patients aged ≥18 years with a diagnosis of deep vein thrombosis or pulmonary embolism ascertained from inpatient claims. Patients were included if they initiated anticoagulants within 30 days of their first VTE diagnosis, completed 6 months of therapy defined as ≥83% proportion days covered with oral anticoagulants during the initial 6-month period, and received extended treatment with either apixaban or warfarin or no extended therapy. We compared the risks of recurrent VTE and major bleeding between apixaban, warfarin, and no treatment groups. To adjust for differences in baseline characteristics and clinical factors (e.g., HAS-BLED score, active cancer, and provoked VTE) between groups, we used the stabilized inverse probability treatment weighting (IPTW) method. Follow-up continued until the occurrence of the first event, switch to the comparator, disenrollment, death, or end of the study period. Multivariable Cox proportional hazards modeling with IPTW was used to obtain adjusted hazard ratios (aHR) and 95% confidence intervals (95%CI).Results: The study cohort (mean age=74 ±12 years, 40% male, 76% White) consisted of 2,315 users of extended apixaban treatment (83% with 5 mg twice a day and 17% with 2.5 mg twice a day; mean duration=6.2 months), 2,757 users of extended warfarin treatment (mean duration=8.2 months), and 2,328 patients with no extended treatment following completion of an initial 6 months of anticoagulant treatment. The incidence rates of recurrent VTE were 0.42, 1.73, and 1.72 per 100 person-years, and those of major bleeding were 2.28, 3.62, and 1.43 per 100 person-years in the apixaban, warfarin, and no treatment groups, respectively (Table 1). Compared to no extended treatment, the use of apixaban was associated with an 80% decreased risk of recurrent VTE (aHR=0.19, 95%CI=0.06-0.55) without increasing the risk of major bleeding (aHR=1.19, 95%CI=0.65-2.19); the use of warfarin did not lower the risk of recurrent VTE (aHR=0.75, 95%CI=0.42-1.37) but increased the risk of major bleeding (aHR=1.92, 95%CI=1.13-3.25). Compared to the use of warfarin, the use of apixaban was associated with a decreased risk of recurrent VTE (aHR=0.26, 95% CI=0.09-0.76) and no difference in major bleeding risk (aHR=0.61, 95%CI=0.36-1.06). These findings remained consistent in subgroup (e.g., patients with provoked vs. unprovoked VTE, patients with active cancer vs. those without, and patients with chronic kidney diseases vs. those without) and sensitivity analyses (e.g., ≥92% proportion days covered with oral anticoagulants during the initial 6-month period).Conclusions: Compared to no extended therapy, extended anticoagulation with apixaban was associated with a reduced risk of recurrent VTE without increasing the risk of major bleeding, whereas warfarin did not lower risk of recurrent VTE but increased the risk of major bleeding among Medicare beneficiaries with VTE. In the head-to-head comparison, the use of apixaban was more effective than warfarin in preventing recurrent VTE, without increasing the risk of major bleeding events. Our findings suggest that apixaban is an effective and safer option for extended treatment of VTE when compared to warfarin or no treatment among Medicare beneficiaries with VTE. [Display omitted] DisclosuresPark: BMS/Pfizer Alliance American Thrombosis Investigator Initiated Research Program: Research Funding. Kang: BMS/Pfizer Alliance American Thrombosis InvestigatorInitiated Research Program: Research Funding. Huang: BMS/Pfizer Alliance American Thrombosis Investigator Initiated Research Program: Research Funding. Lo-Ciganic: MERCK: Research Funding; BMS/Pfizer Alliance American Thrombosis Investigator Initiated Research Program: Research Funding. Dietrich: BMS/Pfizer Alliance American Thrombosis Investigator Initiated Research Program: Research Funding. Murphy: North American Thrombosis Foundation: Honoraria. DeRemer: BMS/Pfizer Alliance American Thrombosis Investigator Initiated Research Program: Research Funding; Portola Pharmaceuticals: Current equity holder in publicly-traded company; BMS advisory board attendee: Honoraria.

Characteristics of patients receiving extended treatment after incident venous thromboembolism

Given high recurrence risk after venous thromboembolism (VTE), guidelines recommend extended dose rivaroxaban (10mg OD) or apixaban (2.5mg BID) to be considered after 6months of initial treatment. This study aimed to provide insight into clinical practice regarding the use of extended preventive treatment and to describe duration of the initial treatment. Linkage of nationwide health registers identified all in- and outpatients with VTE from April 2017 through 2018. Hazard ratios (HR) with 95% confidence intervals (CIs) were calculated adjusting for other VTE-related factors. The study included 6030 patients with VTE. Among rivaroxaban users, 2.2% (n= 113) received the extended 10-mg dose after mean 9.4 (SD 3.1) months of standard treatment. For apixaban, 4.7% (n= 40) received extended 2.5-mg dose after mean 8.0months (SD 3.9). After adjustments, incident pulmonary embolism (HR 1.81 95% CI 1.12;2.91) and trauma/fracture (HR 1.42 95% CI 0.46;4.43) were associated with switching to extended dose, whereas patients with unprovoked VTE were less likely to receive the extended dose (HR 0.68 95% CI 0.30;1.55). Less than 3% of patients with incident VTE received extended treatment after initial standard treatment. Even though international guidelines suggest that the risk-benefit balance is in favour of extended VTE treatment, this was yet to be translated into clinical practice as of 2018. Studies using contemporary data are warranted to investigate routine clinical practice of extended treatment for VTE recurrence.

Heavy menstrual bleeding in women on anticoagulant treatment for venous thromboembolism: Comparison of high‐ and low‐dose rivaroxaban with aspirin

BackgroundRivaroxaban may induce heavy menstrual bleeding. It is unknown if this effect is dose related or if rivaroxaban is associated with more menstrual bleeding than aspirin. ObjectivesTo demonstrate and compare menstrual patterns and actions taken among women receiving aspirin and two doses of rivaroxaban. MethodsThe EINSTEIN‐CHOICE trial compared once‐daily rivaroxaban 20 mg, rivaroxaban 10 mg, and aspirin 100 mg for extended treatment of venous thromboembolism in patients who had completed 6 to 12 months of anticoagulant therapy. In 362 women with menstrual cycles, menstrual flow duration and intensity assessed at days 30, 90, 180, and 360 were compared with those before starting anticoagulant therapy. ResultsMenstrual flow duration increased in 12%‐18% of the 134 women given 20‐mg rivaroxaban, in 6% to 12% of 120 women given 10‐mg rivaroxaban, and in 9% to 12% of 108 women given aspirin. Corresponding increases in flow intensity were 19% to 24%, 14% to 21%, and 13% to 20%. The odds ratios (ORs) for increased menstrual flow duration were 1.36 (95% confidence interval [CI], 0.62‐2.96) for rivaroxaban 20 mg versus aspirin, 0.77 (95% CI, 0.33‐1.81) for rivaroxaban 10 mg versus aspirin, and 0.57 (95% CI, 0.26‐1.25) for rivaroxaban 10 mg versus 20 mg. The ORs for increased menstrual flow intensity were 1.41 (95% CI, 0.67‐2.99), 1.07 (95% CI, 0.49‐2.34), and 0.76 (95% CI, 0.37‐ 1.57), respectively. ConclusionsThere were no statistically significant differences in menstrual hemorrhage patterns between women treated with 10 or 20 mg of rivaroxaban and aspirin. Compared with 10‐mg rivaroxaban or aspirin, 20‐mg rivaroxaban showed numerically more often increased menstrual flow duration and intensity. [Display omitted]

Anticoagulation for Patients with Venous Thromboembolism: When is Extended Treatment Required?

The need for extended venous thromboembolism (VTE) treatment beyond 3 to 6 months is usually determined by balancing the risk of recurrence if treatment is stopped against the risk of bleeding from continuing treatment. The risk of recurrence, and in turn the decision to extend, can be determined through the nature of the index event. Patients with VTE provoked by surgery or trauma (major transient risk factors) are recommended to receive 3 months of anticoagulation therapy because their risk of recurrence is low, whereas patients with VTE provoked by a major persistent risk factor, such as cancer, or those considered to have “unprovoked” VTE, are recommended to receive an extended duration of therapy based on an established high risk of recurrence. Nonetheless, recent evidence and new guidance identify that this approach fails to consider patients with risk factors classed as minor transient (e.g., impaired mobility and pregnancy) or minor persistent (e.g., inflammatory bowel disease and congestive heart disease). Indeed, the risk of recurrence with respect to VTE provoked by minor persistent risk factors has been demonstrated to be not dissimilar to that of VTE without identifiable risk factors. This review provides an overview of the available data on the risk of recurrence according to the underlying cause of VTE, a critical evaluation of evidence from clinical studies on the available anticoagulants for extended VTE treatment, models of risk prediction for recurrent VTE and bleeding, and guidance on how to apply the evidence in practice.

Broadening the Categories of Patients Eligible for Extended Venous Thromboembolism Treatment.

Traditionally, venous thromboembolism (VTE) resulting from major transient risk factors (e.g., surgery or trauma) or a major persistent risk factor such as cancer, has been defined as being provoked, whereas unprovoked VTE encompasses events without an identifiable cause. These categorizations influence anticoagulant treatment duration; unlike VTE provoked by major transient risk factors, extended anticoagulation beyond 3 months is advised for patients with cancer or unprovoked VTE due to risk persistence after treatment cessation. However, some patients with VTE provoked by minor transient or minor persistent risk factors may also be candidates for extended anticoagulation therapy due to the continuing risk of recurrence. In patients who require extended therapy, vitamin K antagonists (VKAs) are effective but are associated with an increased risk of bleeding and various treatment burdens (e.g., anticoagulation monitoring and dose adjustment). Evaluations of extended VTE treatment with the less-burdensome direct oral anticoagulants such as apixaban, dabigatran, edoxaban, and rivaroxaban show that they are at least as safe and effective as VKAs in a broad range of patients. In addition, apixaban and rivaroxaban offer more than one dosing option, allowing tailoring of treatment to the patient's specific risk factor profile. Analysis of more granular definitions for risk factor groupings has also yielded vital information on the most appropriate strategies for the treatment of patients with specific risk factors, highlighting that extended anticoagulation treatment may benefit those with minor transient and persistent environmental and nonenvironmental risk factors who commonly receive shorter-duration therapy.

PF795 EXPLORING THE REAL‐LIFE CLINICAL VALUE OF LOW DOSE DIRECT ANTICOAGULANTS FOR SECONDARY PREVENTION OF THROMBOEMBOLISM

Background:Anticoagulation is the mainstay of acute venous thromboembolism (VTE) therapy. Until recently Vitamin‐K antagonists (VKAs) were the standard of care for extended treatment of VTE. In the last decade, direct oral anticoagulants (DOACs) have been studied and approved for use in treatment and secondary prevention of VTE. The apixaban AMPLIFY‐EXTEND clinical trial and the rivaroxaban EINSTEIN CHOICE study, have offered evidence that low dose anticoagulation up to 12 months following completion of standard VTE treatment, can be equally effective to standard dose apixaban/rivaroxaban for secondary prevention of thromboembolism. To date there is no real‐life study recording the outcomes of patients on low dose DOACs in this setting.Aims:In this audit, we sought to identify patients on long term low dose apixaban/rivaroxaban for secondary prevention of VTE and record their outcomes.Methods:Between January 2015 and September 2018, 4,625 patients were initiated to DOACs in our clinics. Amongst them 394 patients were put on either apixaban 2.5 mg bd (N = 352) or rivaroxaban 10 mg od (N = 42). Their median age was 65(16–98) years. The index event to offer long term anticoagulation was unprovoked VTE in 271 patients while 123 had suffered a provoked VTE with permanent risk factors. Cancer‐associated thrombosis was recorded in 42 patients, 69 individuals had documented thrombophilia and/or family history of thrombosis. Recurrent VTE was recorded in 41 patients. The median time from thrombosis to low‐dose anticoagulation switch was 7.26(3–280) months. The median follow‐up time on low dose anticoagulation was 15(3–45) months.Results:Major bleeding occurred in 3/394 patients (0.76%), all 3 patients were on low dose apixaban. Major plus clinically relevant non‐major bleeding was recorded in 30 patients (7.6%). Recurrent VTE occurred in 13/352 patients (3.69%) in the apixaban group and 1/42 patients (2.3%) in the rivaroxaban group (p = NS). No statistical differences in bleeding rate and VTE recurrence were identified between the total patient population, the cancer related thrombosis and the thrombophilia/family history of VTE subgroup respectively (table).Summary/Conclusion:Our study although small, is the first to record the clinical experience of using long term low dose DOACs to prevent VTE recurrence in real life. Our results confirm that low dose DOACs are very safe with major bleeding rate oof &lt;1% in 15 months. We did however find a higher incidence of recurrent VTE (3.55%) compared to the AMPLIFY‐EXTEND (1.7%) and the EINSTEIN CHOICE (1.2%) trials.image

Safety of direct oral anticoagulants versus traditional anticoagulants in venous thromboembolism.

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality worldwide. For decades, low molecular weight heparins (LMWH) and vitamin K-antagonists have been the gold standard of anticoagulation for VTE. Recently, direct oral anticoagulants (DOACs) that can be administered in fixed doses, without laboratory monitoring and dose adjustment have revolutionized anticoagulation management in VTE. Here, we report on recent evidence regarding the safety of DOACs compared to traditional anticoagulants in surgical and medical prophylaxis as well as in acute and extended treatments of VTE. Additionally, we provide data on special situations such as elderly, cancer and renal impairment patients. Regarding antithrombotic prophylaxis, data are lacking on DOAC use in general surgical patients, while DOACs appear to be more effective than and as safe as LMWHs in VTE prophylaxis for major orthopedic surgical patients. Whether a medically ill patient may benefit from extended VTE prophylaxis remains unclear. In fact, in these patients, DOACs showed an increased risk of bleeding compared to conventional therapy. In the acute treatment of VTE, DOACs were non-inferior and probably safer than conventional anticoagulation therapy while in the extended VTE treatment DOACs were more effective than placebo or aspirin with a comparable risk of major bleeding. These favorable results were also confirmed in elderly, cancer and renal impairment patients. However, further investigations are needed in order to generalize the safe use of DOACs in these specific subgroups of patients.

Direct oral anticoagulants for extended treatment of venous thromboembolism: insights from the EINSTEIN CHOICE study.

The risk of recurrence of venous thromboembolism (VTE) persists after interruption of the initial anticoagulation therapy. New evidence shows that direct oral anticoagulants are effective for extended treatment of VTE and may reduce the risk of all-cause mortality. The optimal duration of anticoagulation after VTE is, however, controversial and complicated by the need for individualised assessment and balance between thrombosis and bleeding risks. Three direct oral anticoagulants (rivaroxaban, apixaban and dabigatran) have been studied for extended treatment of VTE. Dabigatran was shown to be safer than vitamin K antagonists and similarly effective for the prevention of recurrent VTE. Dabigatran, apixaban and rivaroxaban resulted in significant decreases in the rate of recurrent symptomatic VTE when compared to placebo, without a statistically significant difference in the risk of major bleeding. The latest guidelines of the American College of Chest Physicians suggest the use of low-dose aspirin to prevent VTE recurrence in patients who want to stop anticoagulation. In the randomised, double-blind, phase 3 EINSTEIN CHOICE trial, once-daily rivaroxaban at doses of 20 mg or 10 mg and 100 mg of aspirin were compared in VTE patients for whom there was clinical equipoise for extended anticoagulation. Either a treatment dose (20 mg) or a prophylactic dose (10 mg) of rivaroxaban significantly reduced the risk of VTE recurrence without a significant increase in bleeding risk compared with aspirin. The EINSTEIN CHOICE trial included patients with provoked or unprovoked VTE. Patients with VTE provoked by minor persistent or minor transient risk factors enrolled in this trial had not-negligible VTE recurrence rates. These new findings on extended therapy suggest the possibility of anticoagulation regimens at intensities tailored to the patients' risk profiles and VTE characteristics, with a shift of the risk-benefit balance in favour of extended treatment.

Rivaroxaban and the EINSTEIN clinical trial programme.

Rivaroxaban, a direct oral anticoagulant, is widely used for the treatment of venous thromboembolism (VTE) in adult patients. The approval of rivaroxaban for the treatment of deep vein thrombosis and pulmonary embolism and the extended secondary prevention of recurrent VTE is based on the results of the EINSTEIN DVT and EINSTEIN PE trials, and the EINSTEIN EXT and EINSTEIN CHOICE trials, respectively. This review provides an updated overview of these completed EINSTEIN studies in adult patients, including results of subanalyses in patients at high risk of recurrent VTE, and discusses the emerging data from the EINSTEIN Junior programme, which is evaluating the use of rivaroxaban for the treatment of paediatric VTE. In the EINSTEIN DVT and EINSTEIN PE trials, rivaroxaban (15 mg twice daily for 21 days, followed by 20 mg once daily thereafter) was shown to be an effective and safe alternative to standard anticoagulation for the treatment of deep vein thrombosis and pulmonary embolism in a broad range of adult patients. These results are supported by increasing amounts of real-world data from patients treated with rivaroxaban in routine clinical practice worldwide. In the EINSTEIN EXT and EINSTEIN CHOICE trials, rivaroxaban was superior to placebo and acetylsalicylic acid, respectively, for the extended treatment of VTE – physicians can now choose between two doses of rivaroxaban (20 mg once daily or 10 mg once daily) for the extended prevention of recurrent VTE, based on a patient's risk of recurrence, bleeding and personal preferences.

Venous thromboembolism and cancer: Current and future role of direct-acting oral anticoagulants

Approximately one-fifth of all cases of venous thromboembolism (VTE) are related to cancer and anticoagulant treatment in these patients has remained a challenge. Cancer patients with VTE are at increased risk of developing recurrent VTE compared to patients without cancer, but also have a higher risk of major bleeding. In these patients, low molecular weight heparins (LMWHs) have been shown to be more effective and as safe as vitamin K-antagonists (VKAs) for the treatment of VTE. Therefore, the majority of current clinical guidelines recommend LMWHs as the treatment of choice for cancer-associated VTE. However, several issues should be considered regarding the use of LMWHs as daily subcutaneous injections, the costs or risk of heparin-induced thrombocytopenia. In recent years, direct-acting oral anticoagulants (DOACs) have shown similar efficacy and better safety profile compared to VKAs and have become the standard of care for the treatment of VTE in the general population. Because DOACs offer a simple oral treatment regimen without the need for anticoagulation control, they could be an attractive alternative to LMWH.Before DOACs become an accepted treatment option for cancer associated VTE, they have to be evaluated in a head-to-head comparison with LMWH. Data from two randomized trials comparing DOACs vs. LMWH have recently been published. In the present review, we will provide three clinically relevant questions on the use of DOACs in patients with cancer and VTE and provide an overview on recent evidence on this topic: 1) are DOACs a treatment option for the prevention of VTE in cancer patients?; 2) what is the place for DOACs in patients with cancer-associated VTE?; 3) should I use DOACs for the extended treatment of cancer-related VTE?.

Long-Term Management of Venous Thromboembolism: Lessons from EINSTEIN CHOICE and Other Extension Trials.

Many patients with venous thromboembolism (VTE) are at risk of recurrence if anticoagulant therapy is stopped. Whereas 3 months of anticoagulation treatment is sufficient for patients with VTE provoked by major surgery or trauma, in many cases a longer course is needed. Extended therapy with vitamin K antagonists (VKAs) requires frequent coagulation monitoring and dose adjustments to ensure that the international normalized ratio (INR) remains within the therapeutic range; furthermore, there is a risk of major bleeding even if a therapeutic INR is maintained. Therefore, more convenient and safer anticoagulants are needed.The non-VKA oral anticoagulants (NOACs)-apixaban, dabigatran, edoxaban and rivaroxaban-simplify extended therapy because they can be given in fixed doses without routine coagulation monitoring. Randomized clinical trials have demonstrated the efficacy and safety of NOACs for extended VTE treatment, but bleeding remains a concern. Patients and physicians may, therefore, be reluctant to continue anticoagulation beyond 3 to 6 months except in patients at high risk of recurrence. Acetylsalicylic acid (ASA) is often prescribed instead of an anticoagulant because of its perceived lower risk of bleeding; however, the recent EINSTEIN CHOICE trial demonstrated that once-daily rivaroxaban at a dose of either 20 or 10 mg reduced the risk of recurrent VTE by 70% compared with ASA without significantly increasing the risk of bleeding. In this review, we discuss the EINSTEIN CHOICE trial in the context of previous trials for extended VTE treatment and examine some of the lessons that can be applied to clinical practice.

Patient Management Strategies and Long-Term Outcomes in Isolated Distal Deep-Vein Thrombosis versus Proximal Deep-Vein Thrombosis: Findings from XALIA.

Background Overall, 30 to 50% of lower-limb deep-vein thrombosis (DVT) cases are isolated distal DVT (IDDVT). The recurrent venous thromboembolism (VTE) risk is unclear, leaving uncertainty over optimal IDDVT treatment. We present data on patients with IDDVT and proximal DVT (PDVT) from the prospective, noninterventional XALIA study of rivaroxaban for acute and extended VTE treatment. Methods Patients aged ≥18 years scheduled to receive ≥3 months' anticoagulation with rivaroxaban or standard anticoagulation were eligible, with follow-up for ≥12 months. We describe baseline characteristics, management strategies, and incidence proportions of VTE recurrence, major bleeding, and all-cause mortality in patients with IDDVT or PDVT, with or without distal vein involvement. Findings Overall, 1,004 patients with IDDVT and 3,098 with PDVT were enrolled; 641 (63.8%) and 1,683 (54.3%) received rivaroxaban, respectively. Patients with IDDVT were younger and had lower incidences of renal impairment, cancer, and unprovoked VTE than those with PDVT. On-treatment recurrence incidences for IDDVT versus PDVT were 1.0 versus 2.4% (adjusted hazard ratio [HR]: 0.56; 95% confidence interval [CI]: 0.29–1.08), and incidences posttreatment cessation were 1.1 versus 2.1% (adjusted HR: 0.65; 95% CI: 0.32–1.35), respectively. On-treatment major bleeding incidences were 0.9 versus 1.4% and mortality was 0.8 versus 2.2%, respectively. Median treatment duration in patients with IDDVT was shorter than in those with PDVT (102 vs. 192 days, respectively). Interpretation Patients with IDDVT had fewer comorbidities and were more frequently treated with rivaroxaban than those with PDVT. On-treatment and posttreatment recurrences were less frequent in patients with IDDVT. Trial registration number: NCT01619007.

Review: In VTE, reduced- and full-dose extended DOAC therapies do not differ and are better than no extended therapy.

Source Citation Vasanthamohan L, Boonyawat K, Chai-Adisaksopha C, Crowther M. Reduced-dose direct oral anticoagulants in the extended treatment of venous thromboembolism: a systematic review and me...