Long-term Anticoagulation With Rivaroxaban for Preventing Recurrent VTE: A Benefit-Risk Analysis of EINSTEIN-Extension

Quantitative Benefit-Risk Evaluation of Rivaroxaban in Patients After Peripheral Arterial Revascularization: The VOYAGER PAD Trial

BACKGROUND

The VOYAGER PAD (Efficacy and Safety of Rivaroxaban in Reducing the Risk of Major Thrombotic Vascular Events in Subjects With Symptomatic Peripheral Artery Disease Undergoing Peripheral Revascularization Procedures of the Lower Extremities) trial compared rivaroxaban (2.5 mg twice a day) plus aspirin with aspirin alone in patients with symptomatic peripheral artery disease requiring endovascular or surgical limb revascularization, with 50% receiving clopidogrel background therapy. The New Drug Indication application includes benefit-risk assessments using clinical judgment to balance benefits against risks. During its review, the US Food and Drug Administration requested additional quantitative benefit-risk analyses with formal weighting approaches.

METHODS AND RESULTS

Benefits and risks were assessed using rate differences between treatment groups (unweighted analysis). To account for clinical importance of the end points, a multi-criteria decision analysis was conducted using health state utility values as weights. Monte Carlo simulations incorporated statistical uncertainties of the event rates and utility weights. Intent-to-treat and on-treatment analyses were conducted. For unweighted intent-to-treat analyses, rivaroxaban plus aspirin would result in 120 (95% CI, -208 to -32) fewer events of the primary composite end point (per 10 000 patient-years) compared with aspirin alone. Rivaroxaban caused an excess of 40 (95% CI, 8-72) Thrombolysis in Myocardial Infarction major bleeding events, which was largely driven by nonfatal, nonintracranial hemorrhage Thrombolysis in Myocardial Infarction major bleeding events. For weighted analyses, rivaroxaban resulted in the utility equivalent of 13.7 (95% CI, -85.3 to 52.6) and 68.1 (95% CI, 7.9-135.7) fewer deaths per 10 000 patient-years (intent-to-treat and on-treatment, respectively), corresponding to probabilities of 64.4% and 98.7%, respectively, that benefits outweigh risks favoring rivaroxaban per Monte Carlo simulation.

CONCLUSIONS

These analyses show a favorable benefit-risk profile of rivaroxaban therapy in the VOYAGER PAD trial, with findings generally consistent between the unweighted and weighted approaches.

Optimal length of oral anticoagulant treatment for maximum benefit within 5 years after discontinuation of oral anticoagulants in patients with acute pulmonary embolism who require secondary thromboprophylaxis

BACKGROUND

Extended oral anticoagulant (OA) use is recommended in patients with acute pulmonary embolism (PE) who require secondary thromboprophylaxis. Nevertheless, the optimal length of OA use for the maximum long-term benefit in this patient population has been undefined to date.

METHODS

A retrospective study was performed to explore the role of different length of overall OA use (group 1 (≥1 year of OA use and <2 years of OA use), group 2 (≥2 years of OA use and <3 years of OA use), group 3 (≥ 3 years of OA use)) in outcomes within 5 years after OA discontinuation in patients with acute PE, who required secondary thromboprophylaxis. The primary outcome was mortality rates. The secondary outcomes comprised venous thromboembolism (VTE) recurrence, major bleeding during OA use and net clinical benefit. Net clinical benefit was defined as the composite of recurrent VTE and major bleeding.

RESULTS

For a total of 385 patients in group 1 (n=220), group 2 (n=110) and group 3 (n=55), the PE-related mortality in group 1 was higher than that in group 2 (p=0.034) and 3 (p=0.040), respectively, whereas were similar between groups 2 and 3 (p=1.000). The net clinical benefit in group 1 was less than that in group 2 (p=0.024), whereas similar with that in group 3 (p=0.526). The net clinical benefit was comparable between groups 2 and 3 (p=0.716). The length of OA use was positively associated with major bleeding (HR, 2.510 (0.293 to 3.485), p=0.001), whereas negatively associated with PE-related mortality (HR, 0.668 (0.196 to 2.832), p=0.025) and VTE recurrence (HR, 0.694 (0.174 to 2.300), p=0.036), respectively. The sensitivity and specificity of the length of OA use for the tendency of PE-related mortality was 70.2% and 46.2%, respectively. The area under the curve (AUC) was 0.654 (0.514 to 0.793) (p=0.029). The sensitivity and specificity of the length of OA use for the tendency of net clinical benefit was 86.8% and 64.3%, respectively. The AUC was 0.628 (0.565 to 0.690) (p<0.001) CONCLUSIONS: For patients with acute PE who require secondary thromboprophylaxis, 2 to 3 years (30 months preferred) of overall OA use after a diagnosis of acute PE could be an optimal length to achieve maximum benefit within 5 years after OA discontinuation.

Quantitative Benefit-Risk Assessment in Medical Product Decision Making: A Good Practices Report of an ISPOR Task Force

Benefit-risk assessment is commonly conducted by drug and medical device developers and regulators, to evaluate and communicate issues around benefit-risk balance of medical products. Quantitative benefit-risk assessment (qBRA) is a set of techniques that incorporate explicit outcome weighting within a formal analysis to evaluate the benefit-risk balance. This report describes emerging good practices for the 5 main steps of developing qBRAs based on the multicriteria decision analysis process. First, research question formulation needs to identify the needs of decision makers and requirements for preference data and specify the role of external experts. Second, the formal analysis model should be developed by selecting benefit and safety endpoints while eliminating double counting and considering attribute value dependence. Third, preference elicitation method needs to be chosen, attributes framed appropriately within the elicitation instrument, and quality of the data should be evaluated. Fourth, analysis may need to normalize the preference weights, base-case and sensitivity analyses should be conducted, and the effect of preference heterogeneity analyzed. Finally, results should be communicated efficiently to decision makers and other stakeholders. In addition to detailed recommendations, we provide a checklist for reporting qBRAs developed through a Delphi process conducted with 34 experts.

Benefit-Risk Assessment of Rivaroxaban for Extended Thromboprophylaxis After Hospitalization for Medical Illness

Background Venous thromboembolism (VTE) often occurs after hospitalization in medically ill patients, but the population benefit-risk of extended thromboprophylaxis remains uncertain. Methods and Results The MARINER (Medically Ill Patient Assessment of Rivaroxaban Versus Placebo in Reducing Post-Discharge Venous Thrombo-Embolism Risk) study (NCT02111564) was a randomized double-blind trial that compared thromboprophylaxis with rivaroxaban 10 mg daily versus placebo for 45 days after hospital discharge in medically ill patients with a creatinine clearance ≥50 mL/min. The benefit-risk balance in this population was quantified by calculating the between-treatment rate differences in efficacy and safety end points per 10 000 patients treated. Clinical characteristics of the study population were consistent with a hospitalized medical population at risk for VTE. Treating 10 000 patients with rivaroxaban resulted in 32.5 fewer symptomatic VTE and VTE-related deaths but was associated with 8 additional major bleeding events. The treatment benefit was driven by the prevention of nonfatal symptomatic VTE (26 fewer events). There was no between-treatment difference in the composite of critical site or fatal bleeding. Conclusions Extending thromboprophylaxis with rivaroxaban for 45 days after hospitalization provides a positive benefit-risk balance in medically ill patients at risk for VTE who are not at high risk for bleeding. Registration URL: https://clinicaltrials.gov/; Unique identifier: NCT02111564.

Impact of direct oral anticoagulants on evolution of post-thrombotic syndrome

BACKGROUND

The effect of direct oral anticoagulants (DOACs) on evolution of a post-thrombotic syndrome (PTS) is unknown.

METHODS AND RESULTS

This retrospective study included patients (n = 98) with a PTS occurring after a proximal deep-vein thrombosis (DVT). The PTS progression was assessed by the Villalta scale change over time from when patients were started on DOACs for the prevention of DVT recurrence according to current guidelines. The PTS evolution was compared between patients with good (n = 63) vs. poor (n = 35) DOACs adherence, defined by using a medication possession ratio cut point of 0.80. The mean follow-up was 41.7 ± 17.7 and 27.5 ± 10.5 months in patients with good or poor adherence, respectively. The primary endpoint of PTS improvement (defined when the Villalta score became <5 and/or decreased by ≥30% from baseline) was higher in patients with good vs. poor adherence (66.7% vs. 20%, p < 0.001). None of the patients in the good adherence group experienced at any time of follow-up the co-primary endpoint of PTS worsening (defined as the Villalta score increase ≥30%), which instead occurred in 12 (34.3%) of those with poor adherence (p < 0.001). All study-defined primary endpoints occurred within 2 years. The mean values of the Villalta partial scores related to the subjective symptoms (patient-rated) and to the potentially reversible physician-rated signs were significantly improved in the good adherence group, while they were unchanged among patients with poor adherence.

CONCLUSIONS

In this study a good vs. poor DOACs adherence was associated with a more favorable progression of PTS over a long-term follow-up. Larger studies are needed to explore the clinical efficacy of DOACs on PTS manifestations.

Anticoagulant-associated gastrointestinal bleeding: Framework for decisions about whether, when and how to resume anticoagulants

Gastrointestinal (GI) bleeding is the most frequent single site of oral anticoagulant (OAC)-associated major bleeding. Patients with major GI bleeding experience morbidity and a substantial risk of short-term all-cause mortality up to 10%. While OACs are frequently discontinued during acute bleeding, there is substantial uncertainty about whether, when, and how OACs should be resumed after bleeding has resolved. Limited evidence suggests a lower risk of thromboembolism and death, and a higher risk of recurrent bleeding with OAC resumption. However, the absolute risks and optimal timing of anticoagulation remain uncertain based on these observational studies at risk of bias, particularly due to baseline confounding. In addition to an individualized approach to determining the benefits and harms of treatment decisions informed by the best available evidence about thrombosis and recurrent bleeding, discussions should meaningfully incorporate patient values and preferences. The objective of this review is to provide a framework for decision-making by summarizing the epidemiology and clinical outcomes of OAC-associated GI bleeding, providing an approach for assessment and risk stratification for OAC resumption and its timing, and outlining strategies for the prevention of recurrent GI bleeding.

Prevention and Management of COVID-19-Associated Venous Thromboembolism

Распространение новой коронавирусной инфекции SARS-CoV-2, классифицируемой сейчас как COVID-19, приобрело глобальный характер. Врачи, занимающиеся лечением пациентов с COVID-19, ежедневно сталкиваются с новыми и неожиданными проблемами. Коронавирусная болезнь может быть причиной системной коагулопатии и тромботических осложнений. Недавние исследования подтвердили крайне высокую частоту встречаемости тромбоэмболических событий, в особенности в группе пациентов с тяжелым течением коронавирусной пневмонии. Сепсис-индуцированная активация коагуляционного каскада в сочетании с широкой распространенностью в общей популяции известных факторов риска венозной тромбоэмболии (ВТЭ) способствуют развитию в организме протромботического статуса. Аномальные параметры коагуляции связаны с плохим прогнозом для пациентов с COVID-19-пневмонией. Определенные гематологические биомаркеры, включая D-димер, могут выступать в качестве предикторов тромботических событий и неблагоприятных исходов заболевания. Вероятность развития тромботических осложнений следует определять у всех пациентов с COVID-19, которые входят в группу высокого риска ВТЭ и имели несколько неблагоприятных факторов до начала коронавирусной инфекции (более 8 баллов по шкале Caprini). В случаях развития сепсис-индуцированной коагулопатии антикоагулянтная терапия, по-видимому, связана с лучшим прогнозом в отношении смертности. Уровень D-димера может служить показателем эффективности антикоагулянтной терапии, однако такой подход не является общепринятым. В настоящем обзоре литературы обобщены накопленные на сегодняшний день эпидемиологические данные и текущие рекомендации по профилактике и лечению COVID-19-ассоциированной ВТЭ. Дальнейшие исследования должны быть сосредоточены на разработке оптимальных стратегий диагностики и профилактики COVID-19-ассоциированной ВТЭ и связанной с ней летальности

The disease caused by coronavirus SARS-CoV-2, named CoViD-19, has become a global emergency. Physicians that treat patients with COVID-19 face new and unexpected challenges every day. COVID-19 can lead to systemic coagulation activation and thrombotic complications. Recent studies confirmed very high cumulative incidence of thromboembolic events, particularly in critically illpatients with COVID-19 pneumonia. The sepsis-related activation of the coagulation combined with high prevalence of common thrombotic risk factors can contribute to this prothrombotic state. Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia. Coagulation biomarkers, including D-dimer, can help in the identification of patients with the risk of complications and mortality. D-dimers may be used to monitor the effectiveness of anticoagulants, although this practice is not universally accepted. Risk assessment in admission is important to identify high-risk patients with multiple risk factors before the onset of the viral infection (Caprini score >8). In case of sepsis-induced coagulopathy, anticoagulant therapy appears to be associated with better prognosis in relation to mortality. In this review, we summarize available epidemiological data on venous thromboembolism and recommendations on thromboprophylaxis in COVID-19. Future research should focus on optimal diagnostic and prophylactic strategies to prevent VTE and potentially improve survival.

Treatment of Cancer-Associated Venous thrombosis with Direct Oral Anticoagulants

Стандартная антикоагулянтная терапия онко-ассоциированного венозного тромбоза (ОАТ) антагонистами витамина K может быть затруднена или невозможна вследствие осложнений геморрагического характера и лекарственных взаимодействий на фоне противоопухолевой химиотерапии, а также в результате низкой приверженности пациентов к лечению низкомолекулярными гепаринами (НМГ). Вполне логично предположить, что прямые оральные антикоагулянты (ПОАК) в определенной степени могли бы позволить преодолеть указанные проблемы, однако до недавнего времени отсутствовали крупные клинические исследования, посвященные оценке их эффективности и безопасности у онкологических пациентов. В настоящем обзоре обобщены выводы современных клинических руководств и рекомендаций, результаты последних рандомизированных контролируемых испытаний (SELECT-D, Hokusai-VTE Cancer, CARAVAGGIO, ADAM VTE), данные реальной клинической практики, связанные с применением ПОАК для лечения ОАТ. На основании изученного материала было сделано заключение о необходимости использования НМГ в терапии ОАТ на протяжении по меньшей мере 36 месяцев. Вместе с тем полученные сведения указали на высокую частоту отказа пациентов от лечения НМГ и бльшую приверженность к приему оральных антикоагулянтов, в том числе ПОАК. Исследование Hokusai-VTE Cancer продемонстрировало схожие суммарные показатели рецидива венозной тромбоэмболии (ВТЭ) и больших кровотечений в группах пациентов, получавших эдоксабан и дальтепарин (12,8 vs 13,5), в то время как наиболее высокий риск кровотечения на фоне приема эдоксабана был отмечен при гастроинтестинальном (ГИ) раке. Изучение ривароксабана в исследовании SELECT-D указало на меньшее количество рецидивов ВТЭ (4 vs 11), сопоставимый уровень больших кровотечений (6 vs 4) по сравнению с дальтепарином. Осложнения геморрагического характера наблюдались преимущественно при раке желудочно-кишечной и урогенитальной локализации наибольшее количество ривароксабан-ассоциированных больших кровотечений было у пациентов с опухолями пищевода и/или желудка (36 vs 11). Сравнительное исследование апиксабана/ дальтепарина (CARAVAGGIO) в настоящее время продолжается, а предварительные результаты проекта ADAM-VTE оказались весьма убедительными. Таким образом, ПОАК являются обоснованной альтернативой НМГ в лечении ОАТ. При ГИ раке назначение ПОАК следует рассматривать в каждом случае отдельно с учетом соотношения риск польза.

Standard anticoagulant therapy of cancer-associated venous thrombosis (СAT) with vitamin K antagonists may be troublesome or impossible due to hemorrhagic complications and drug interactions on the background of antitumor chemotherapy and decreased patients adherence to treatment with low molecular weight heparins (LMWH). It is quite logical to assume that direct oral anticoagulants (DOAC) could resolve such problems to some extent however, until recently, there were no large clinical trials to assess their effectiveness and safety in cancer patients. This review summarizes the findings of modern clinical guidelines and recommendations, the obtained data of the latest randomized controlled trials (SELECT-D, Hokusai-VTE Cancer, CARAVAGGIO, ADAM VTE) and those of real clinical practice related to the use of DOAC for CAT treatment. On the base of the studied material, it was concluded that it is reasonable to use LMWH in CAT treatment for at least 36 months. At the same time, according to the obtained information, a high proportion of patients refused LMWH treatment and demonstrated their greater commitment to taking oral anticoagulants, including DOAC. The Hokusai-VTE Cancer Study showed similar overall rates of VTE recurrence and major bleedings in groups of patients treated with edoxaban and dalteparin (12.8 vs 13.5), while the highest risk of bleeding was noted in gastrointestinal (GI) cancer patients treated with edoxaban. Assessment of rivaroxaban in the SELECT-D study revealed fewer VTE relapses (4 vs 11), a similar level of major bleedings (6 vs 4) compared to dalteparin. Hemorrhagic complications were observed mainly in GI and urogenital cancer patients the largest number of rivaroxaban-associated major bleedings was in patients with tumors of the esophagus and/or stomach (36 vs 11). A comparative study of apixaban/dalteparin (CARAVAGGIO) is ongoing, but the preliminary results of the ADAM-VTE project turned out to be very convincing. Thus, DOAC is a reasonable alternative to LMWH in CAT treatment. In GI cancer, administration of DOACs should be considered in each case separately taking into account the risk-benefit ratio.

A randomised controlled trial of extended anticoagulation treatment versus standard treatment for the prevention of recurrent venous thromboembolism (VTE) and post-thrombotic syndrome in patients being treated for a first episode of unprovoked VTE (the ExACT study)

Venous thromboembolism (VTE) is prevalent and impactful, with a risk of death, morbidity and recurrence. Post-thrombotic syndrome (PTS) is a common consequence and associated with impaired quality of life (QoL). The ExACT study was a non-blinded, prospective, multicentred randomised controlled trial comparing extended versus limited duration anticoagulation following a first unprovoked VTE (proximal deep vein thrombosis or pulmonary embolism). Adults were eligible if they had completed ≥3 months anticoagulation (remaining anticoagulated). The primary outcome was time to first recurrent VTE from randomisation. The secondary outcomes included PTS severity, bleeding, QoL and D-dimers. Two-hundred and eighty-one patients were recruited, randomised and followed up for 24 months (mean age 63, male:female 2:1). There was a significant reduction in recurrent VTE for patients receiving extended anticoagulation [2·75 vs. 13·54 events/100 patient years, adjusted hazard ratio (aHR) 0·20 (95% confidence interval (CI): 0·09 to 0·46, P < 0·001)] with a non-significant increase in major bleeding [3·54 vs. 1·18 events/100 patient years, aHR 2·99 (95% CI: 0·81-11·05, P = 0·10)]. Outcomes of PTS and QoL were no different between groups. D-dimer results (on anticoagulation) did not predict VTE recurrence. In conclusion, extended anticoagulation reduced VTE recurrence but did not reduce PTS or improve QoL and was associated with a non-significant increase in bleeding. Results also suggest very limited clinical utility of D-dimer testing on anticoagulated patients.

Evaluation of the safety and effectiveness of direct oral anticoagulants and low molecular weight heparin in gastrointestinal cancer-associated venous thromboembolism

BACKGROUND

Gastrointestinal cancer (GICA) is associated with a higher incidence of venous thromboembolism (VTE) compared to other solid tumors, moreover, recurrent VTE and major bleeding (MB) complications during anticoagulation treatment have an associated increase rate. GICA-VTE remains a challenging clinical scenario with MB concerns for utilization of direct oral anticoagulants (DOAC), especially with active cancer therapies.

AIM

To evaluate patient risk factors, effectiveness (VTE) and safety (MB) of DOACs and low molecular weight heparin (LMWH) in patients with active GICA-VTE.

METHODS

A retrospective chart review of patients receiving DOACs and LMWH with GICA and symptomatic or incidental VTE treated at comprehensive cancer center from November 2013 to February 2017 was performed. Inclusion criteria included active GI cancer diagnosed at any stage or treatment +/- 6 mo of VTE diagnosis, whom were prescribed 6 mo or more of DOACs or LMWH. The Chi-squared test was used for overall and the Fisher exact test for pairwise comparisons of the proportions of patients experiencing recurrent VTE and MB events. Odds ratios were used to compare the relative odds of the occurrence of the outcome given exposure to the risk factor.

RESULTS

A total of 144 patients were prescribed anticoagulation, in which 106 fulfilled inclusion criteria apixaban (27.3%), rivaroxaban (34.9%) and enoxaparin (37.7%), and 38 were excluded. Patients median age was 66.5 years at GICA diagnosis and 67 years at CAVTE event, with 62% males, 80% Caucasian, 70% stage IV, pancreatic cancer (40.5%), 30% Khorana Score (≥ 3 points), and 43.5% on active chemotherapy. Sixty-four percent of patients completed anticoagulation therapy (range 1 to 43 mo). Recurrent VTE at 6 mo was noted in 7.5% (n = 3), 6.8% (n = 2) and 2.7% (n = 1) of patients on enoxaparin, apixaban and rivaroxaban, respectively (all P = NS). MB at 6 mo were 5% (n = 2) for enoxaparin, 6.8% (n = 2) for apixaban and 21.6% (n = 8) for rivaroxaban (overall P = 0.048; vs LMWH P = 0.0423; all other P = NS). Significant predictors of a primary or secondary outcome for all anticoagulation therapies included: Active systemic treatment (OR = 5.1, 95%CI: 1.3-19.3), high Khorana Score [≥ 3 points] (OR = 5.5, 95%CI: 1.7-17.1), active smoker (OR = 6.7, 95%CI: 2.1-21.0), pancreatic cancer (OR = 6.8, 95%CI: 1.9-23.2), and stage IV disease (OR = 9.9, 95%CI: 1.2-79.1).

CONCLUSION

Rivaroxaban compared to apixaban and enoxaparin had a significantly higher risk of MB on GICA-VTE patients with equivocal efficacy.

Efficacy of low-dose rivaroxaban in an 88-year-old female with pulmonary embolism: A case report

RATIONALE

Rivaroxaban has numerous advantages over traditional anticoagulation therapy. Fixed doses can be administered without requiring routine monitoring of coagulation, and anticoagulation efficacy is more predictable. Safety, including fewer drug interactions, and reduced bleeding, is also improved with rivaroxaban based on current recommendations. The goal of this report was to explore if low-dose rivaroxaban 10 mg once daily was effective in an elderly patient who developed minor bleeding when treated with rivaroxaban (10 mg twice daily) for a pulmonary embolism.

PATIENT CONCERNS

We present an 88-year-old female with dyspnea and fatigue, which became increasingly worse over a month in the absence of medication. Her weight was 64 kg. Routine coagulation assays and renal function were normal at time of admission.

DIAGNOSIS

Deep vein thrombosis and pulmonary embolism were confirmed by venous compression ultrasonography and computed tomography pulmonary angiography.

INTERVENTIONS

Oral rivaroxaban 10 mg twice daily was administered, but the patient developed hemoptysis and gum bleeding 5 days later. The dose of rivaroxaban was reduced to 10 mg once daily, and bleeding gradually disappeared after 3 days.

OUTCOME

At follow-up 90 days after treatment, the patient reported no discomfort. Venous compression ultrasonography and computed tomography pulmonary angiography showed normal results; therefore, treatment was terminated.

LESSONS

Elderly patients exhibit variable tolerance of anticoagulants, warranting careful consideration of the risk of bleeding. Low-dose rivaroxaban was an effective treatment for pulmonary embolism in the elderly patient presented here.

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.

Multidisciplinary approach to the management of patients with pulmonary embolism and deep vein thrombosis: a consensus on diagnosis, traditional therapy and therapy with rivaroxaban

Despite the availability of updated guidelines for the diagnosis and treatment of venous thromboembolism (VTE), the management of this disorder in clinical practice is often not standardized, given the different degree of compliance with official recommendations by the various involved specialists. The aim of this consensus paper, as a result of a board of experts in thromboembolism, is to define strategies to improve the quality of patients' care and the efficiency of healthcare resources utilization, by means of: (a) analysis of the guidelines for diagnosis and treatment of VTE; (b) analysis of diagnostic and therapeutic algorithms currently used in clinical practice by different specialists; (c) agreement on a common algorithm for diagnosis and treatment of VTE in different clinical settings; (d) definition of the possible role of the new oral anticoagulant agents (NOAC), such as rivaroxaban, based on their potential benefits for both acute and chronic therapy. The so-called "single drug approach" (as opposed to the traditional heparin/VKA combination), which can be adopted with these drugs, makes anticoagulation more convenient for both patients and healthcare providers, without the need for a close monitoring of the hemocoagulative status, and with a concomitant reduction of length of hospitalization and treatment costs. Among NOACs, in this paper we focused on rivaroxaban only because it was the unique available NOAC in Italy for the treatment of VTE at the time the manuscript was written. Concerning rivaroxaban, the results of two phase III, randomized and controlled trials confirm the non-inferiority of this drug compared to standard therapy (enoxaparin/warfarin) for the treatment of patients with pulmonary embolism (EINSTEIN PE Study) or deep vein thrombosis (EINSTEIN DVT Study) in terms of both efficacy and safety, supporting its use as an effective therapeutic option for these disorders.

The secondary prevention of venous thromboembolism: Towards an individual therapeutic strategy

After the anticoagulant withdrawal, a substantial proportion of patients with venous thromboembolism will develop recurrent events. Whether to consider an extended treatment depends on the risk of recurrence and bleeding risk. The assessment of the individual risk profile remains a difficult task. Several basal and post-basal factors modulate the risk of recurrence and may help clinicians to select patients who can benefit from the extended therapy. During the year 2017, new evidence regarding the post-basal factors was provided by the Morgagni and Scope studies. Another interesting novelty was the VTE-BLEED score, the first bleeding risk score that obtained the external validation in venous thromboembolism setting. In secondary prevention, the use of direct oral anticoagulants is growing instead of vitamin K antagonist. Even at lower doses, direct oral anticoagulants showed to be effective and safe, to reduce all-cause mortality and seemed to be superior to placebo for the composite outcome of fatal bleeding and fatal recurrence. After the recently published Einstein-Choice trial, the role of aspirin has become truly marginal as rivaroxaban 10 mg showed a bleeding risk similar to aspirin 100 mg but a greater effectiveness reducing the relative risk of recurrence by about 70%. Another option for secondary prevention could be sulodexide, with a lower protective effect than direct oral anticoagulants but an interesting safety profile. In conclusion, in our opinion, an individual strategy taking into account the risk of recurrence, bleeding risk, therapeutic options and patient preferences is the most appropriate approach to secondary prevention of venous thromboembolism.

Cost comparison of continued anticoagulation with rivaroxaban versus placebo based on the 1-year EINSTEIN-Extension trial efficacy and safety results

AIMS

The EINSTEIN-Extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (vs placebo) after 6-12 months of initial anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small non-significant increased risk of major bleeding (none fatal or in critical site). This study aimed to compare total healthcare cost between rivaroxaban and placebo, based on the EINSTEIN-EXT event rates.

METHODS

Total healthcare cost was calculated as the sum of treatment and clinical event costs from a US managed care perspective. Treatment duration and event rates were obtained from the EINSTEIN-EXT study. Adjustment on treatment duration was made by assuming a 10% non-adherence rate. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e. recurrent deep vein thrombosis [DVT], recurrent pulmonary embolism, major bleeding, clinically relevant non-major bleeding) were determined from the literature. Results were examined over a ±20% range of each cost component and over 95% confidence intervals (CIs) of event rate differences in deterministic (one-way) and probabilistic sensitivity analyses (PSA).

RESULTS

Total healthcare cost was $1,454 lower for rivaroxaban-treated (vs placebo-treated) patients in the base-case, with a lower clinical event cost fully offsetting drug cost. The cost savings of recurrent DVT alone (-$3,102) was greater than drug cost ($2,723). Total healthcare cost remained lower for rivaroxaban in the majority (73%) of PSA (cost difference [95% CI] = -$1,454 [-$2,396, $1,231]).

LIMITATIONS

This study was conducted over the 1-year observation period of the EINSTEIN-EXT trial, which limited "real-world" applicability and examination of long-term economic impact. Assumptions on drug and clinical event costs were US-based and, thus, not applicable to other healthcare systems.

CONCLUSIONS

Total healthcare costs were estimated to be lower for patients continuing rivaroxaban therapy compared to those receiving placebo in VTE patients who had completed 6-12 months of VTE treatment.

Net clinical benefit of rivaroxaban compared with warfarin in atrial fibrillation: Results from ROCKET AF

AIMS

The aim of this study was to determine the net clinical benefit (NCB) of rivaroxaban compared with warfarin in patients with atrial fibrillation.

METHODS

This was a retrospective analysis of 14,236 patients included in ROCKET AF who received at least one dose of study drug. We analyzed NCB using four different methods: (1) composite of death, stroke, systemic embolism, myocardial infarction, and major bleeding; (2) method 1 with fatal or critical organ bleeding substituted for major bleeding; (3) difference between the rate of ischemic stroke or systemic embolism minus 1.5 times the difference between the rate of intracranial hemorrhage; and (4) weighted sum of differences between rates of death, ischemic stroke or systemic embolism, intracranial hemorrhage, and major bleeding.

RESULTS

Rivaroxaban was associated with a lower risk of the composite outcome of death, myocardial infarction, stroke, or systemic embolism (rate difference per 10,000 patient-years [RD]=-86.8 [95% CI -143.6 to -30.0]) and fatal or critical organ bleeding (-41.3 [-68 to -14.7]). However, rivaroxaban was associated with a higher risk of major bleeding other than fatal or critical organ bleeding (55.9 [14.7 to 97.2]). Method 1 showed no difference between treatments (-35.5 [-108.4 to 37.3]). Methods 2-4 favored treatment with rivaroxaban (2: -96.8 [-157.0 to -36.8]; 3: -65.2 [-112.3 to -17.8]; 4: -54.8 [-96.0 to -10.2]).

CONCLUSIONS

Rivaroxaban was associated with favorable NCB compared with warfarin. The NCB was attributable to lower rates of ischemic events and fatal or critical organ bleeding.

Non-vitamin K antagonist oral anticoagulants for pulmonary embolism: who, where and for how long?

INTRODUCTION

Acute pulmonary embolism (PE) is a relatively common cardiopulmonary emergency that is a major cause of hospitalization and morbidity and is the primary cause of mortality associated with venous thromboembolism (VTE). During the last decade, one of the biggest changes in the management of PE has been the approval of four non-vitamin K antagonist oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban and rivaroxaban) for the treatment of PE and deep vein thrombosis and secondary prevention of VTE. Areas covered: This article reviews the evolving management of PE in the NOAC era and addresses three fundamental questions: who should receive NOACs over conventional heparin/vitamin K antagonist regimens for the treatment of acute PE; should patients be treated as inpatients or outpatients; and how long should patients be treated to reduce the risk of recurrence? Expert commentary: The management of PE is changing. NOACs provide new anticoagulant treatment options for patients with PE, based on Phase III clinical study results. The consistent efficacy and safety profile of NOACs across many PE patient subgroups, including the elderly, fragile patients, those with active cancer and high-risk (right ventricular dysfunction) patients, suggests NOAC use will increase among these patients.

Rivaroxaban versus nadroparin for preventing deep venous thrombosis after total hip arthroplasty following femoral neck fractures: A retrospective comparative study

Objective This study was performed to evaluate the efficacy of rivaroxaban versus nadroparin for preventing deep venous thrombosis (DVT) in elderly patients with osteoporosis undergoing initial total hip arthroplasty (THA) for femoral neck fractures. Methods Prospectively maintained databases were reviewed to retrospectively compare elderly patients with osteoporosis who underwent initial THA for femoral neck fractures from 2007 to 2015. The patients received peroral rivaroxaban at 10 mg/day for 2 weeks or subcutaneous injections of nadroparin at 0.3 mL/day for 2 weeks until the primary analysis cut-off date. The time to first on-study DVT was the primary endpoint. Results In total, 399 patients were included (rivaroxaban group: n=200; mean age, 70.20 ± 9.16 years and nadroparin group: n = 199; mean age, 69.90 ± 8.87 years), with a mean 3-year follow-up. The time to first on-study DVT was significantly longer in the rivaroxaban than nadroparin group (12 and 5 days, respectively). The incidence of DVT within the 2-week follow-up was significantly higher in the nadroparin than rivaroxaban group (6.8% and 19.7%, respectively), but this difference was no longer present at the final follow-up. Conclusion Rivaroxaban was associated with a significant reduction in the occurrence of first on-study DVT compared with nadroparin.

Pharmacological management of pulmonary embolism

INTRODUCTION

Pulmonary embolism (PE) is a common and potentially severe manifestation of venous thromboembolism. Its management has relied on anticoagulation by vitamin K antagonists (VKA) for the past fifty years. Recently, new alternative drugs have been developed and dramatically modified both the treatment of acute PE and its secondary prevention. Areas covered: This review discusses the contemporary pharmacological treatment for PE, with a focus on anticoagulation options for non-high risk PE. In particular, the advent of direct oral anticoagulants (rivaroxaban, apixaban, edoxaban and dabigatran) and modalities for long-term prevention will be described. Options for anticoagulation for pregnancy-related PE are presented separately. Expert opinion: Direct oral anticoagulants represent the first-line therapy of non-high risk PE, with better risk-benefit ratios compared with VKA due to lower bleeding risks. In specific groups of patients, however, older generations of anticoagulants such as VKA or heparins still play an important role. Multiple alternatives are available for the secondary prevention of PE, with different efficacies in reducing thrombotic risk and bleeding safety profiles.

Choosing wisely: The impact of patient selection on efficacy and safety outcomes in the EINSTEIN-DVT/PE and AMPLIFY trials

BACKGROUND

The results of the EINSTEIN-DVT/PE and AMPLIFY trials, which compared rivaroxaban and apixaban with conventional anticoagulation therapy for acute venous thromboembolism (VTE), respectively, are often compared. However, the trials differed in duration of therapy (3-12 and 6months, respectively) and in patient selection (few exclusion criteria and more stringent exclusion criteria, respectively).

METHODS

To determine the effect of these methodological differences on outcomes, the patients enrolled in EINSTEIN-DVT/PE were divided into 2 cohorts; the 5253 patients that matched the exclusion criteria for AMPLIFY and were treated for at least 6months (cohort 1) and the 2368 patients who would have been ineligible for AMPLIFY (cohort 2).

RESULTS

Compared with patients in cohort 2, those in cohort 1 were older and more often male and there were more with unprovoked VTE, prior VTE, cancer and known thrombophilia. In cohort 1, rivaroxaban would have significantly reduced recurrent VTE (relative risk [RR], 0.64; 95% confidence interval [CI], 0.43-0.95) and major bleeding (RR, 0.50; 95% CI, 0.30-0.82) compared with conventional therapy, whereas the two treatments would have had similar effects on recurrent VTE (RR, 1.08; 95% CI, 0.65-1.79) and major bleeding (RR, 1.03; 95% CI, 0.48-2.18) in cohort 2.

CONCLUSIONS

This analysis illustrates the influence of patient selection and treatments duration on outcome results and highlights the limitations of cross-trial comparisons.