Effectiveness and safety of rivaroxaban versus warfarin for treatment and prevention of recurrence of venous thromboembolism

Proteomic analysis of extracellular vesicle cargoes mirror the cardioprotective effects of rivaroxaban in patients with venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) remains a significant cause of morbidity and mortality worldwide. Rivaroxaban, a direct oral factor Xa inhibitor, mediates anti-inflammatory and cardiovascular-protective effects besides its well-established anticoagulant properties; yet, these remain poorly characterized. Extracellular vesicles (EVs) are considered proinflammatory messengers regulating a myriad of (patho)physiological processes and may be highly relevant to the pathophysiology of VTE. The effects of Rivaroxaban on circulating EVs in VTE patients remain unknown. We have established that differential EV biosignatures are found in patients with non-valvular atrial fibrillation anticoagulated with Rivaroxaban versus warfarin. Here, we investigated whether differential proteomic profiles of circulating EVs could also be found in patients with VTE.

METHODS AND RESULTS

We performed comparative label-free quantitative proteomic profiling of enriched plasma EVs from VTE patients anticoagulated with either Rivaroxaban or warfarin using a tandem mass spectrometry approach. Of the 182 quantified proteins, six were found to be either exclusive to, or enriched in, Rivaroxaban-treated patients. Intriguingly, these proteins are involved in negative feedback regulation of inflammatory and coagulation pathways, suggesting that EV proteomic signatures may reflect both Rivaroxaban's anti-coagulatory and anti-inflammatory potential.

CONCLUSIONS

These differences suggest Rivaroxaban may have pleiotropic effects, supporting the reports of its emerging anti-inflammatory and cardiovascular-protective characteristics relative to warfarin.

Safety profile of rivaroxaban in first-time users treated for venous thromboembolism in four European countries

BACKGROUND

The European rivaroxaban post-authorization safety study evaluated bleeding risk among patients initiated on rivaroxaban or vitamin K antagonists for the treatment and secondary prevention of venous thromboembolism in routine clinical practice.

METHODS

Cohorts were created using electronic healthcare databases from the UK, the Netherlands, Germany and Sweden. Patients with a first prescription of rivaroxaban or vitamin K antagonist during the period from December 2011 (in the UK, January 2012) to December 2017 (in Germany, December 2016) for venous thromboembolism indication, with no record of atrial fibrillation or recent cancer history, were observed until the occurrence of each safety outcome (hospitalization for intracranial, gastrointestinal, urogenital or other bleeding), death or study end (December 2018; in Germany, December 2017). Crude incidence rates of each outcome per 100 person-years were computed.

RESULTS

Overall, 44 737 rivaroxaban and 45 842 vitamin K antagonist patients were enrolled, mean age, 59.9-63.8 years. Incidence rates were similar between rivaroxaban and vitamin K antagonist users with some exceptions, including higher incidence rates for gastrointestinal bleeding in rivaroxaban users than in vitamin K antagonist users. Among rivaroxaban users, mortality and bleeding risk generally increased with age, renal impairment and diabetes.

CONCLUSIONS

This study provides further data from routine clinical practice that broadly support safety profile of rivaroxaban for VTE indication and complement findings from previous randomized clinical trials.

Association of type of oral anticoagulation with risk of bleeding in 45,114 patients with venous thromboembolism during initial and extended treatment-A nationwide register-based study

BACKGROUND

Safety data for different anticoagulant medications in venous thromboembolism (VTE) are scarce, in particular for extended treatment.

OBJECTIVES

To compare major bleeding rates depending on the choice of anticoagulation during initial (first 6 months) and extended treatment (6 months up to 5 years).

METHODS

A nationwide register-based study including cancer-free patients with a first-time VTE between 2014 and 2020. Cox proportional hazards models were used to compare bleeding rates.

RESULTS

We included 6558 patients on warfarin, 18,196 on rivaroxaban, and 19,498 on apixaban. At 6 months, 4750 (72.4%) remained on warfarin, 11,366 (62.5%) on rivaroxaban, and 11,940 (61.2%) on apixaban. During initial treatment, major bleeding rates were 3.86 (95% CI 3.14-4.58), 2.93 (2.55-3.31), and 1.95 (1.65-2.25) per 100 patient-years for warfarin, rivaroxaban, and apixaban, respectively, yielding adjusted hazard ratios (aHRs) of 0.89 (95% CI 0.71-1.12) for rivaroxaban versus warfarin, 0.55 (0.43-0.71) for apixaban versus warfarin, and 0.62 (0.50-0.76) for apixaban versus rivaroxaban. During extended treatment, major bleeding rates were 1.55 (1.19-1.91), 1.05 (0.85-1.26), and 0.96 (0.78-1.15) per 100 patient-years for warfarin, rivaroxaban, and apixaban, respectively, with aHRs of 0.72 (0.53-0.99) for rivaroxaban versus warfarin, 0.60 (0.44-0.82) for apixaban versus warfarin, and 0.85 (0.64-1.12) for apixaban versus rivaroxaban. Previous bleeding and increasing age were risk factors for bleeding both during initial and extended treatment.

CONCLUSION

Apixaban had a lower bleeding risk than warfarin or rivaroxaban during initial treatment. During extended treatment, bleeding risk was similar for apixaban and rivaroxaban, and higher with warfarin.

Trends and factors associated with outpatient anticoagulant treatment initiation among VTE patients with active cancer

BACKGROUND

Patients with venous thromboembolism (VTE) and cancer are at higher risk of recurrent VTE and mortality. Clinical guidelines recommend anticoagulant treatment for these patients. This study assessed trends in outpatient anticoagulant treatment and factors associated with this treatment initiation in outpatient setting among this high-risk patient population.

OBJECTIVE

To study trends and factors associated with anticoagulant treatment initiation among patients with VTE and cancer.

METHODS

VTE cancer patients age ≥65 were identified from the SEER-Medicare database from 01JAN2014-31DEC2019. Patients were enrolled for ≥6 months prior to their first VTE (i.e. index event) and without evidence of other reasons for anticoagulation (i.e., atrial fibrillation). Patients were also required to be enrolled for ≥30 days after index. Cancer status was identified from SEER or Medicare database in the 6 months pre- through 30 days post-VTE. Patients were classified into treated or untreated cohorts depending on whether they initiated outpatient anticoagulant treatment within 30 days post-index. The trends of treated vs. untreated were evaluated by quarter. Logistic regression was used to identify demographic-, VTE-, cancer- and comorbid-related factors associated with anticoagulant treatment initiation.

RESULTS

A total of 28,468 VTE-cancer patients met all study criteria. Of these, ~46 % initiated outpatient anticoagulant treatment within 30 days, and ~54 % did not. The above rates were stable from 2014 to 2019. Factors such as VTE diagnosis in inpatient setting, pulmonary embolism (PE) diagnosis, and pancreatic cancer were associated with increased odds whereas bleeding history and some comorbid factors were associated with decreased odds of initiating anticoagulant treatment.

CONCLUSION

Over half of VTE patients with cancer did not initiate outpatient anticoagulant treatment within the first 30-days after VTE diagnosis. This trend was stable from 2014 to 2019. A range of cancer-, VTE-, and comorbid-related factors were associated with the likelihood of the treatment initiation.

Ruptured innominate artery pseudoaneurysm presenting as hoarseness in Behçet’s syndrome: a case report

Background

Vascular involvement is an infrequent clinical manifestation of Behçet’s syndrome. Owing to the rarity of arterial involvement in Behçet’s syndrome, there is limited experience in managing this phenomenon.

Case presentation

Here, we report a 28-year-old Iranian man with a Behçet’s syndrome background, who presented with shoulder pain and hoarseness. Chest computed tomography angiography was conducted with a suspicion of a vascular pathology causing pressure on the recurrent laryngeal nerves. The patient was diagnosed with a ruptured innominate artery pseudoaneurysm. An innominate artery to the right common carotid artery bypass was performed, and the pseudoaneurysm was excised and replaced with an expandable polytetrafluoroethylene graft. Eventually, the patient was discharged after an uneventful hospital course.

Conclusion

It appears that we are still a long way from finding the optimal treatment for Behçet’s syndrome vascular involvement, and a combination of surgical and medicinal treatments is required.

Recurrent thromboembolism, bleeding, and mortality in Asian patients with venous thromboembolism receiving different oral anticoagulants: A nationwide analysis

Venous thromboembolism (VTE) is associated with a high risk of morbidity and mortality. However, data on the association between oral anticoagulants and the hazards of VTE complications in Taiwanese patients with VTE is limited. This study aimed to compare the hazards of recurrent VTE, bleeding, and mortality between patients with VTE receiving rivaroxaban, a non-vitamin K antagonist oral anticoagulant (NOAC), and those receiving heparin or low-molecular-weight heparin (LMWH) followed by warfarin. Patients with VTE treated with rivaroxaban, or heparin or LMWH followed by warfarin were enrolled from 2 million random samples from Taiwan's National Health Insurance database between 2013 and 2016. Hazards of recurrent VTE (deep vein thrombosis and pulmonary embolism), major bleeding, and mortality in rivaroxaban and warfarin users were investigated. Survival analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Users of rivaroxaban (183) and warfarin (456) were included in the study. Patients receiving rivaroxaban did not have significantly lower hazards of developing recurrent VTE (HR, 0.72 [CI, 0.37-1.37], P = .31) and mortality (HR, 0.86 [CI, 0.49-1.50], P = .59) than those receiving heparin or LMWH followed by warfarin. In addition, the hazard ratio of major bleeding was not significantly different between the 2 regimens (HR, 1.80 [CI, 0.39-8.29], P = .45). Rivaroxaban was not associated with lower risks of recurrent VTE and mortality and higher hazards of major bleeding than heparin or LMWH followed by warfarin in Taiwanese patients with VTE. Clinicians may tailor oral anticoagulants for VTE patients according to the patient's characteristics, cost-effectiveness and healthcare system policy.

Dilemmas in the Choice of Adequate Therapeutic Treatment in Patients with Acute Pulmonary Embolism—From Modern Recommendations to Clinical Application

Pulmonary thromboembolism is a very common cardiovascular disease, with a high mortality rate. Despite the clear guidelines, this disease still represents a great challenge both in diagnosis and treatment. The heterogeneous clinical picture, often without pathognomonic signs and symptoms, represents a huge differential diagnostic problem even for experienced doctors. The decisions surrounding this therapeutic regimen also represent a major dilemma in the group of patients who are hemodynamically stable at initial presentation and have signs of right ventricular (RV) dysfunction proven by echocardiography and positive biomarker values (pulmonary embolism of intermediate–high risk). Studies have shown conflicting results about the benefit of using fibrinolytic therapy in this group of patients until hemodynamic decompensation, due to the risk of major bleeding. The latest recommendations give preference to new oral anticoagulants (NOACs) compared to vitamin K antagonists (VKA), except for certain categories of patients (patients with antiphospholipid syndrome, mechanical valves, pregnancy). When using oral anticoagulant therapy, special attention should be paid to drug–drug interactions, which can lead to many complications, even to the death of the patient. Special population groups such as pregnant women, obese patients, patients with antiphospholipid syndrome and the incidence of cancer represent a great therapeutic challenge in the application of anticoagulant therapy. In these patients, not only must the effectiveness of the drugs be taken into account, but great attention must be paid to their safety and possible side effects, which is why a multidisciplinary approach is emphasized in order to provide the best therapeutic option.

Effectiveness and safety of oral anticoagulants in the treatment of acute venous thromboembolism: A nationwide comparative cohort study in France

INTRODUCTION

Data from clinical trials indicate that direct oral anticoagulants (DOACs) are non-inferior and safer than conventional therapy (low-molecular weight heparin followed by a vitamin K antagonist [VKA]) for treating venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism (PE). This study compared the effectiveness and safety of DOACs and conventional therapy in a real-world setting.

MATERIALS AND METHODS

This observational study used French national claims data of adult, treatment-naïve patients diagnosed with VTE (majority PE) who were hospitalized and treated for VTE with a DOAC (apixaban or rivaroxaban) or VKAs during 2013-2018. Patients with active cancer were excluded. After propensity score matching for each DOAC-VKA comparison, risks of bleeding, recurrent VTE, and all-cause mortality were compared at 6 months. Cox proportional-hazards regression was used to estimate adjusted hazard ratios of the endpoints.

RESULTS

58137 patients were included (10775 VKAs, 10440 apixaban, 36922 rivaroxaban). Propensity score-matched cohort sizes were 7503 for apixaban and 9179 for rivaroxaban. The hazard ratio (95% confidence interval) was significantly lower for apixaban than VKAs for bleeding requiring hospitalization (0.43 [0.32-0.59]), all-cause death (0.61 [0.51-0.74]), and first-recurrent VTE (0.67 [0.52-0.85]). The hazard ratio was also significantly lower for rivaroxaban than VKAs for all-cause death (0.63 [0.53-0.74]) but not for bleeding requiring hospitalization (0.86 [0.69-1.07]) or first-recurrent VTE (0.91 [0.74-1.13]).

CONCLUSIONS

Apixaban was associated with superior safety and effectiveness than VKAs. All-cause mortality was lower in both DOACs than VKAs. Our results support recommendations to use DOACs over VKAs for the treatment of VTE.

Outcomes in 1096 patients with severe thrombotic thrombocytopenic purpura before the Caplacizumab era

INTRODUCTION

Thrombotic thrombocytopenic purpura (TTP) is a diagnostic and therapeutic emergency. Therapeutic plasma exchange (TPE) combined with immunosuppression has been the cornerstone of the initial management. To produce optimal benefits, emerging treatments must be used against a background of best standard of care. Clarifying current uncertainties is therefore crucial.

METHODS

The objective of this study was to analyze a large high-quality database (Marketscan) of TTP patients managed between 2005 and 2014, in the pre-caplacizumab era, in order to assess the impact of time to first TPE and use of first-line rituximab on mortality, and whether mortality declines over time.

RESULTS

Among the 1096 included patients (median age 46 [IQR 35-55], 70% female), 28.8% received TPE before day 2 in the ICU. Hospital mortality was 7.6% (83 deaths). Mortality was independently associated with older age (hazard ratio [HR], 1.024/year; 95% confidence interval [95%CI], [1.009-1.040]), diagnosis of sepsis (HR, 2.360; 95%CI [1.552-3.588]), and the need for mechanical ventilation (HR, 4.103; 95%CI, [2.749-6.126]). Factors independently associated with lower mortality were TPE at ICU admission (HR, 0.284; 95%CI, [0.112-0.717]), TPE within one day after ICU admission (HR, 0.449; 95%CI, [0.275-0.907]), and early rituximab therapy (HR, 0.229; 95% CI, [0.111-0.471]). Delayed TPE was associated with significantly higher costs.

CONCLUSIONS

Immediate TPE and early rituximab are associated with improved survival in TTP patients. Improved treatments have led to a decline in mortality over time, and alternate outcome variables such as the use of hospital resources or longer term outcomes therefore need to be considered.

Management and Outcomes of Isolated Distal Deep Vein Thromboses: A Questionable Trend toward Long-Lasting Anticoagulation Treatment. Results from the START-Register

Background  Isolated distal deep vein thromboses (IDDVT) are frequently diagnosed; however, their natural history and real risk of complications are still uncertain. Though treatment is still not well standardized, international guidelines recommend no more than 3 months of anticoagulation therapy. We investigated how Italian clinicians treat IDDVT patients in their real life in our country.

Methods  Baseline characteristics and clinical history of the patients enrolled in the prospective, observational, multicenter START-Register for a first IDDVT or proximal DVT (PDVT) were analyzed.

Results  Overall, 412 IDDVT patients were significantly younger, with better renal function, and more frequent major transient risk factors, when compared with 1,173 PDVT patients. The anticoagulation duration was >180 days in 52.7% of IDDVT patients (70.7% in PDVT). During treatment, bleeding occurred in 5.6 and 2.8% patient-years in IDDVT and PDVT, respectively ( p  = 0082). Bleeding was more frequent in IDDVT than PDVT patients treated with warfarin (6.8 vs. 3.2 patient-years, p  = 0.0228, respectively). Thrombotic complications occurred in 1.1 and 2.4% patient-years in IDDVT and PDVT patients, respectively. Analyzing together the two groups, 66.1% of bleeds and 86.1% thrombotic complications occurred after 90 days anticoagulation treatment.

Conclusion  The large majority of IDDVT patients received anticoagulation for more than 3 months. Most bleeding and thrombotic complications occurred after the first 90 days of anticoagulation therapy. These results indicate that an extended anticoagulation beyond 90 days in IDDVT patients is associated with increased risk of complications. Whether an extended treatment may lower recurrences after anticoagulation withdrawal should be assessed by specifically designed studies.

The efficacy and safety of direct oral anticoagulants in noncirrhotic portal vein thrombosis

Guidelines currently favor vitamin K antagonists or low-molecular-weight heparins for treatment of noncirrhotic portal vein thrombosis (ncPVT). Use of direct oral anticoagulants (DOACs) in PVT has been met with concern because of the lack of data. We conducted a retrospective study to investigate the efficacy and safety of DOACs for the treatment of ncPVT, and to compare them with standard therapies: 330 patients with ncPVT, followed-up for a mean 41.6 months, received warfarin (n = 108), enoxaparin (n = 70), rivaroxaban (n = 65), apixaban (n = 20), dabigatran (n = 8), fondaparinux (n = 2), or no anticoagulation (n = 57). The primary outcome was complete radiographic resolution (CRR) of PVT. Secondary outcomes included recanalization of occlusive PVT, cavernous transformation of the PV, development of chronic portal hypertensive symptoms (cPHS), and major bleeding. DOACs were associated with the highest CRR rates (dabigatran, 6/8 [75%]; apixaban, 13/20 [65%]; rivaroxaban, 42/65 [65%]). Enoxaparin was associated with a CRR rate similar to that of the DOACs (40/70 = 57%). Warfarin was associated with worse outcomes in this regard (CRR rate, 31% [33/108]; hazard ratio [HR] DOACs:warfarin, 2.91; 95% confidence interval [CI], 1.87-4.52; P < .0001). DOACs were associated with recanalization rates similar to enoxaparin and greater than warfarin (HR DOACs:warfarin, 3.45; 95% CI, 1.93-6.18; P < .0001). DOACs were associated with lower rates of cPHS, although this did not attain significance (DOACs, 8/93 [9%]; enoxaparin, 13/70 [19%]; warfarin, 31/108 [29%]). DOACs were associated with less major bleeding relative to warfarin (HR DOACs:warfarin, 0.20; 95% CI, 0.05-0.86; P = .0307). Patients harboring JAK2V617F, those with no evident predisposing factor for PVT, and those with occlusive thrombus demonstrated worse outcomes. DOACs appear effective and safe for the treatment of ncPVT.

Anticoagulant treatment for venous thromboembolism: A pooled analysis and additional results of the XALIA and XALIA-LEA noninterventional studies

BACKGROUND

The XALIA and XALIA-LEA prospective, noninterventional studies investigated the safety and effectiveness of rivaroxaban versus standard anticoagulation for venous thromboembolism (VTE) treatment in routine clinical practice across global regions.

OBJECTIVES

This pooled analysis combined their data to determine the incidence of thromboembolic and bleeding events in both treatment groups and addressed specific bleeding patterns in a broad range of patients.

METHODS

Patients with objectively confirmed VTE and an indication for ≥3 months' anticoagulation treatment received rivaroxaban or standard anticoagulation (eg, initial treatment with heparin/fondaparinux, followed by a vitamin K antagonist [VKA]). Treatment choice, dose, management, and duration were at the physician's discretion. Primary outcomes (major bleeding, recurrent VTE, and all-cause mortality) were compared between the two treatment groups. Propensity score stratification, and matching were used to reduce bias due to confounding variables.

RESULTS

Overall, 7129 patients were enrolled from 36 countries; 6445 and 2714 patients were included in the propensity score-stratified and -matched analyses, respectively. Major bleeding and incidences of recurrent VTE were similar between treatment groups; all-cause mortality was lower with rivaroxaban than with standard anticoagulation. The incidences of genitourinary bleeding were higher with rivaroxaban than with standard anticoagulation therapy (46 and 23 events in the matched analysis, respectively). VKA management in real-world practice was suboptimal.

CONCLUSION

XALIA and XALIA-LEA show similar safety and effectiveness profiles of rivaroxaban and standard anticoagulation for VTE treatment in routine practice in many parts of the world. The observations are consistent with results from the phase III EINSTEIN randomized controlled trials.

Comparing Safety and Efficacy of Rivaroxaban with Warfarin for Patients after Successful Stent Placement for Chronic Iliofemoral Occlusion: A Retrospective Single Institution Study

OBJECTIVE

The aim was to compare the safety and effectiveness of rivaroxaban and warfarin as anticoagulants for treating patients with post-thrombotic syndrome (PTS) with chronic iliofemoral venous occlusion undergoing iliofemoral venous stenting.

METHODS

This single institution retrospective study analysed patients with PTS with chronic iliofemoral venous occlusion who were prescribed rivaroxaban or warfarin for one year after successfully undergoing iliofemoral venous stenting. The primary safety and efficacy endpoints were bleeding complication rate and primary patency rate at one year. Secondary outcomes included Villalta score, symptom recurrence rate, ulcer healing rate, and clinically driven target lesion revascularisation (CD-TLR) rate during follow up.

RESULTS

From January 2016 to December 2017, 154 legs from 154 patients were included in this study (69 in rivaroxaban group and 85 in warfarin group). The groups were well matched for patient demographics, clinical characteristics, and procedural details. There was no significant difference between the rivaroxaban group and warfarin group in bleeding complication rate (10% vs. 16%, p = .23, hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.25 - 1.37) at one year, as well as major bleeding complication rate (0% vs. 2%, p = .20, HR 0.16, 95% CI 0.01 - 2.61) and minor bleeding complication rate (10% vs. 14%, p = .40, HR 0.67, 95% CI 0.27 - 1.66). The primary patency rate was higher in the rivaroxaban group at one year (84% vs. 71%, p = .049, HR 0.50, 95% CI 0.26 - 0.96) and at two years (79% vs. 63%, p = .037, HR 0.52, 95% CI 0.29 - 0.93). At a mean follow up of 24 months (range 1 - 42 months), the rivaroxaban group had a significantly lower post-operative Villalta score (4.87 ± 3.51 vs. 6.88 ± 5.85, p = .010, t = 2.64, 95% CI 0.50 - 3.52), lower rate of symptom recurrence (4% vs. 32%, p < .001), lower CD-TLR rates (3% vs. 13%, p = .039), and higher ulcer healing rate (90% vs. 59%, p = .004) than the warfarin group.

CONCLUSION

For PTS patients with chronic iliofemoral venous occlusion undergoing iliofemoral venous stenting, rivaroxaban probably exhibited similar safety but superior efficacy to warfarin. However, further prospective control studies with large sample size are necessary to confirm the results.

Clinical Features and Outcome of Thrombotic Microangiopathies: Comparison between Patients with and without Malignancy

Thrombotic microangiopathy (TMA) is an uncommon complication of cancers, related to the malignancy itself, antineoplastic drugs, or hematopoietic stem cell transplant. It was reported mostly as case series but large data are lacking. We used the large U.S. MarketScan database to compare TMA between patients with and without malignancy. Adult patients hospitalized between 2005 and 2014 with a diagnosis of TMA were included; cancer patients were defined by a diagnosis of cancer within 1 year prior to or during the admission with TMA. Associated inpatient diagnoses, procedures, hospital mortality, and long-term survival were collected. We included 3,227 patients; 617 (19.1%) had cancer (age 54 [44-60] years, 58% female), which was a new diagnosis for 23% of patients. Two-thirds of cancer patients had solid tumors (mostly pancreas, lung, breast, colorectal, and hepatobiliary, half of them metastatic) and one-third had hematological malignancies (lymphoma, acute leukemia, and multiple myeloma); TMA patients with cancer were older, more often men, had more noncancer-related comorbidities, and developed more sepsis and coagulopathy than TMA patients without cancer. Hospital mortality was significantly higher in cancer patients (16.6% vs. 6.1%, p < 0.001) and reached 30% in transplant recipients; malignancy was an independent risk factor for hospital mortality in multivariate analysis and sensitivity analyses excluding patients with metastases or patients who did not undergo plasmapheresis led to similar results. Malignancy was also associated with decreased long-term survival.

Rare pulmonary embolism caused by the combination of bilateral popliteal venous aneurysms and antiphospholipid syndrome

Popliteal venous aneurysm (PVA) and antiphospholipid syndrome (APS) are under-recognised as potential causes of pulmonary embolism (PE). A 66-year-old woman presented with progressive shortness of breath. A contrast-enhanced CT revealed bilateral PE, a small renal infarction and bilateral PVAs. Direct oral anticoagulant (DOAC) therapy was initiated immediately for venous thrombosis. Given the positivity for serum antiphospholipid antibody (aPL) in an initial blood test, low-dose aspirin was included to prevent further arterial thrombosis. Her symptoms resolved and she was discharged 1 week later. Twelve weeks later, she was diagnosed with APS because of persistent aPL. Surgical resection of the right PVA was performed 1 year later from her hospitalisation. To the best of our knowledge, this is the first case of PE caused by the combination of bilateral PVAs and APS. This report emphasises the importance of careful screening to identify PE causes, and its optimal management.

Compared to randomized studies, observational studies may overestimate the effectiveness of DOACs: a metaepidemiological approach

BACKGROUND AND OBJECTIVES

Randomized controlled trials (RCTs) are criticized for including patients who are overselected. Health authorities consequently encourage "real-world" postmarketing cohort studies. Our objective was to determine the differences between RCTs and observational studies as regards their populations and efficacy/safety results.

METHODS

A systematic review was conducted to identify RCTs and observational studies including patients with venous thromboembolism receiving direct oral anticoagulants or conventional treatment. Ratios of hazard ratio (RHR) comparing epidemiological studies (prospective and retrospective cohort studies and studies using living databases) with RCTs were computed.

RESULTS

Six RCTs (27,121 patients) and twenty observational studies (248,971 patients) were identified and analyzed. Prospective cohort studies seemed to recruit patients who were no less selected than those of RCTs whereas other types of observational studies may reflect the population treated in real life. Among observational studies, prospective cohort studies yielded the most favorable estimates of treatment effect compared with RCTs. These studies were associated with a nonsignificant 33% increase in efficacy estimate (RHR 0.67, [95% CI, 0.39-1.18]) but no effect on safety estimate. Studies using living databases were associated with nonsignificant trends toward a greater effect on efficacy (RHR 0.82, [0.66-1.01]) and a smaller effect on safety (RHR 1.33, [0.96-1.84]).

DISCUSSION

Overall, in this clinical setting, an exaggeration of the treatment efficacy estimate was seen with observational studies compared with RCTs.

CONCLUSIONS

As the presence of residual confounding cannot be excluded, these results should be interpreted cautiously.

Rivaroxaban treatment for young patients with pulmonary embolism (Review)

Pulmonary embolism (PE) is a serious, life-threatening condition that affects young populations (>18 and <50 years old, according to most literature reviews) with improved recognition of its clinical manifestations and the widespread use of sensitive imaging techniques, PE is increasingly diagnosed in younger patients. At present, there is limited understanding of the clinical features and adequate anticoagulant treatment options for this population. Most studies to date have yet to demonstrate significant differences in PE pathophysiology or symptoms between young and elderly patients. Although the overall incidence of PE is lower in young populations compared with elderly patients, important risk factors also apply for young patients. Hereditary thrombophilia is common and is a major cause of PE in younger patients. Immobilization, trauma, obesity, smoking and infection are also becoming increasingly frequent in young patients with PE. Among female patients, oral contraceptive use, pregnancy and postpartum status are predominant risk factors underlying PE. Rivaroxaban is a direct oral anticoagulant with a rapid onset of action that is associated with less drug-drug interactions compared with other therapies. Because the drug is administered at fixed doses with no requirement for routine coagulation monitoring, it is becoming an attractive option for anticoagulation treatment in young patients with PE. Therefore, the present literature review focuses on the clinical characteristics of PE and rivaroxaban therapy in younger patients.

Patient self-management of oral anticoagulation with vitamin K antagonists in everyday practice: clinical outcomes in a single centre cohort after long-term follow-up

Background

Patient self-management (PSM) of vitamin K antagonists (VKA) seems a very promising model of care for oral anticoagulation in terms of efficacy and safety. In comparison with other management models of VKA therapy, the number of scientific publications supporting the advantages of PSM is more limited. Currently, most of the scarce information comes from randomized clinical trials. Moreover, a small number of studies have assessed PSM of VKA therapy in real life conditions.

Methods

We analyzed clinical outcomes of 927 patients in a single center (6018.6 patient-years of follow-up). Recruitment took place between 2002 and 2017. All patients followed a structured training program, conducted by specialized nurses.

Results

Fifty percent of individuals had a mechanical heart valve (MHV), 23% suffered from recurrent venous thromboembolism (VTE) or high-risk thrombophilia, and 13% received VKA therapy because of atrial fibrillation (AF). Median follow-up was 6.5 years (range 0.1–15.97 years), median age was 58.1 years (IQR 48–65.9) and 46.5% were women. The incidence of major complications (either hemorrhagic or thromboembolic) was 1.87% patient-years (pt-ys) with a 95% CI of 1.54–2.27. The incidence of major thromboembolic events was 0.86% pt-ys (95% CI 0.64–1.13) and that of major hemorrhagic events was 1.01% pt-ys (95% CI 0.77–1.31). The incidence of intracranial bleeding was 0.22% pt-ys (95% CI 0.12–0.38). In terms of clinical indication for VKA therapy, the incidence of total major complications was 2.4% pt-ys, 2.0% pt-ys, 0.9% pt-ys and 1.34% pt-ys for MHV, AF, VTE and other (including valvulopathies and myocardiopathies), respectively. Clinical outcomes were worse in patients with multiple comorbidities, previous major complications during conventional VKA therapy, and in older individuals. The percentage of time in therapeutic range (TTR) was available in 861 (93%) patients. Overall, the mean (SD) of TTR was 63.6 ± 13.4%, being higher in men (66.2 ± 13.1%) than women (60.6 ± 13.2%), p < 0.05.

Conclusions

In terms of clinically relevant outcomes (incidence of major complications and mortality), PSM in real life setting seems to be a very good alternative in properly trained patients.

Administrative codes inaccurately identify recurrent venous thromboembolism: The CVRN VTE study

BACKGROUND

Studies using administrative data commonly rely on diagnosis codes to identify venous thromboembolism (VTE) events. Our objective was to assess the validity of using International Classification of Disease, 9th Revision (ICD-9) codes in identifying recurrent VTE.

MATERIALS AND METHODS

Among 5497 adults with confirmed incident VTE from four healthcare delivery systems in the Cardiovascular Research Network (CVRN), we identified all subsequent inpatient, emergency department (ED), and ambulatory clinical encounters associated with an ICD-9 code for VTE (combined with relevant radiology procedure codes for inpatient/ED VTE codes in the secondary discharge position or outpatient codes) during the follow-up period. Medical records were reviewed using standardized diagnostic criteria to assess for the presence of new, recurrent VTE. The positive predictive value (PPV) of codes was calculated as the number of valid events divided by total encounters.

RESULTS

We identified 2397 encounters that were considered potential recurrent VTE by ICD-9 codes. However, only 31.1% (95%CI: 29.3-33.0%) of encounters were verified by reviewers as true recurrent VTE. Hospital or ED encounters with VTE codes in the primary position were more likely to represent valid recurrent VTE (PPV 61.3%, 95%CI: 56.7-66.3%) than codes in secondary positions (PPV 35.4%, 95%CI: 31.9-39.3%), or outpatient codes (PPV 20.3%, 95%CI: 18.3-22.5%). PPV was low for all VTE types (29.9% for pulmonary embolism, 38.3% for lower and 37.7% for upper extremity deep venous thrombosis, and 14.1% for other VTE).

CONCLUSIONS

ICD-9 codes do not accurately identify new VTE events in patients with a prior history of VTE.

Comparison of All-Cause Mortality Following VTE Treatment Between Propensity Score-Adjusted Observational Studies and Matched Randomized Controlled Trials: Meta-Epidemiologic Study

BACKGROUND

It is unknown whether propensity score-adjusted observational studies produce results comparable to those of randomized controlled trials (RCTs) that address similar VTE treatment issues.

METHODS

The PubMed and Web of Science databases were systematically searched for propensity score-adjusted observational studies, RCTs, and meta-analyses of RCTs that estimated all-cause mortality following VTE treatment. After identifying distinct clinical treatment issues evaluated in the eligible observational studies, a standardized algorithm was used to identify and match at least one RCT or RCT meta-analysis publication for paired study design analyses. Meta-analyses were used to summarize groups of studies. Treatment efficacy statistics (relative ORs) were compared between the paired observational and RCT studies, and the summary relative ORs for all study design pairs were also calculated.

RESULTS

The observational and RCT study pairs assessed seven clinical treatment issues. Overall, the observational study-RCT pairs did not exhibit significantly different mortality estimates (summary relative OR, 0.89; 95% CI, 0.32-1.46; I2 = 23%). However, two of the seven treatment issue study pairs (thrombolysis vs anticoagulation for pulmonary embolism; once- vs twice-daily enoxaparin for VTE) exhibited a significantly different treatment effect direction, and there was a substantial (nonsignificant) difference in the magnitude of the effect in another two of the study pairs (rivaroxaban vs vitamin K antagonists for VTE; home treatment vs hospitalization for DVT).

CONCLUSIONS

This systematic comparison across seven VTE treatment topics suggests that propensity score-adjusted observational studies and RCTs often exhibit similar all-cause mortality, although differences in the direction or the magnitude of estimated treatment effects may occasionally occur.

TRIAL REGISTRY

PROSPERO; CRD42018087819; URL: http://www.crd.york.ac.uk/PROSPERO.

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.

Healthcare resource use in XALIA: A subgroup analysis of a non-interventional study of rivaroxaban versus standard anticoagulation for deep vein thrombosis

INTRODUCTION

The non-interventional XALIA study compared the safety and effectiveness of rivaroxaban with standard anticoagulation for the treatment of venous thromboembolism in routine clinical practice. This substudy assessed the effect of treatment with rivaroxaban on healthcare resource use, hospital length of stay (LOS) and frequency of hospitalisation.

METHODS

In XALIA, patients aged ≥18 years scheduled to receive ≥3 months of rivaroxaban or standard anticoagulation treatment for deep vein thrombosis (DVT) were eligible. Treatment decisions were at the physician's discretion. Healthcare resource use, including hospital admission for the index DVT and initial LOS, was documented. The main analyses in this substudy were conducted in a 1:1 propensity score-matched set (PMS) of patients, with adjustment for cancer at baseline.

RESULTS

In the PMS analysis, 1124 rivaroxaban-treated patients and 1124 standard anticoagulation-treated patients were included. Baseline characteristics were similar between groups (mean age 60.8 years vs. 61.2 years, DVT only rates of 89.7% vs. 90.2% and cancer rates of 8.4% vs. 8.5%, respectively). Of these, 433/1124 (38.5%) rivaroxaban-treated patients and 438/1124 (39.0%) standard anticoagulation-treated patients were hospitalised. Index event LOS in the PMS analysis was a least-squares mean of 2.6 days shorter with rivaroxaban vs. standard anticoagulation (5.4 vs. 8.0 days; geometric means ratio = 0.67 [95% confidence interval 0.61-0.74, P < 0.001]).

CONCLUSIONS

In XALIA, hospital LOS was shorter with rivaroxaban than with standard anticoagulation, consistent with the phase III study results. DVT treatment with rivaroxaban in routine clinical practice may reduce the cost per patient vs. standard anticoagulation.

Major bleeding with antithrombotic agents: a 2012-2015 study using the French nationwide Health Insurance database linked to emergency department records within five areas - rationale and design of SACHA study

Bleeding represents the most recognized and feared complications of antithrombotic drugs including oral anticoagulants. Previous studies showed inconsistent results on the safety profile. Among explanations, bleeding definition could vary and classification bias exists related to the lack of medical evaluation. To quantify the risk of major haemorrhagic event and event-free survival associated with antithrombotic drugs (vitamin K antagonist [VKA], non-VKA anticoagulant [NOAC], antiplatelet agent, parenteral anticoagulant) in 2012-2015, we linked the French nationwide Health Insurance database (SNIIRAM) with a local 'emergency database' (clinical and biological data collected in clinical records). In the VKA-NOAC comparison, a Cox regression analysis will be used to estimate the hazard ratio of major haemorrhagic event adjusted on gender, modified HAS-BLED score and comorbidities. A distinction on the type of major haemorrhagic event (intracranial, gastrointestinal and other haemorrhagic events) was made. We present here the study protocol and the database linkage results. Using six linkage keys, among 3 837 557 hospital visits identified in SNIIRAM, 5264 have been matched with a major haemorrhagic event identified in the 'emergency database', thus clinically confirmed. The 1090 unmatched haemorrhagic events could be explained by the fact that patients were not extracted in the SNIIRAM database (patients living in accommodation establishment with internal use of pharmacy, military people with specific insurance…). We showed the value of SNIIRAM enrichment with a clinical database, a necessary step to categorize haemorrhagic events by a clinically relevant definition and medical validation; it will allow to estimate more accuracy each type of haemorrhagic event.

Rivaroxaban for the treatment of venous thromboembolism in real life: A single-center prospective study

The clinical profile, evolution and complications of treatment with rivaroxaban in a cohort of patients presenting with venous thromboembolism (VTE) were analyzed in an observational, non-interventional and prospective study.A total of 111 patients were included in the study. Clinical data were collected from the medical history of the patients and recorded in a specific database.Mean age was 63.8 ± 17.4 years, 53.2% of patients were men, 55.9% had at least another concomitant condition, and 40.9% at least 1 VTE risk factor. 54.1% of patients presented with deep venous thrombosis, 32.4% with pulmonary embolism and 13.5% with both conditions simultaneously. The 61% of patients were admitted to hospital and mean hospital length-of-stay was 8.8 ± 9.9 days. After a mean follow-up 530 ± 464 days (median follow-up of 405 days), 3.9% of patients died and VTE recurrence occurred in 2.9% of patients. While receiving rivaroxaban, a first bleeding complication occurred in 8.1%; all events were minor bleeding.Our study supports the current literature data and confirms the similar results of real-life VTE patients with those enrolled in the rivaroxaban pivotal clinical trials. Rivaroxaban may facilitate outpatient treatment and might be considered as a first-line therapy for the management of VTE patients.

Influence of age on the pharmacokinetics, pharmacodynamics, efficacy, and safety of rivaroxaban

OBJECTIVE

Atrial fibrillation, peripheral and coronary artery disease, and venous thromboembolism are major risk factors for stroke, disability, and death in the rapidly growing older (≥ 65 years.) population. In the absence of clear guidelines on the appropriate use of the newer non-vitamin K antagonist oral anticoagulants in this population, this study specifically reviews the available literature for rivaroxaban and the impact of age that may affect the pharmacokinetics, pharmacodynamics, efficacy, and safety of this anticoagulant.

METHODS

This review includes a summary of data obtained from the available literature concerning both older healthy subjects and older patients with various aspects of cardiovascular disease enrolled in rivaroxaban clinical trials and data from real world evidence studies.

RESULTS

Evaluation of the clinical pharmacology in healthy, older adults reveal no clinically relevant effect of age on rivaroxaban pharmacokinetics and pharmacodynamics. Population pharmacokinetic studies in older patients with thromboembolic diseases suggest a moderate effect of increasing age on rivaroxaban clearance, albeit not clinically significant. Additionally, sub-group analyses from large, phase 3 clinical trials demonstrate consistent efficacy and safety in the older patient population vs the overall population. These findings are further supported by real-world evidence studies.

CONCLUSION

A favorable clinical profile with rivaroxaban was observed across age sub-groups, supporting the premise that dosing in older adults does not necessitate adjustment. However, it is prudent that a cautious and individualized approach is taken for treatment with any anticoagulant in older adults.

Effectiveness and Safety of Apixaban versus Warfarin as Outpatient Treatment of Venous Thromboembolism in U.S. Clinical Practice

In the AMPLIFY clinical trial, apixaban was non-inferior to warfarin plus subcutaneous enoxaparin bridge therapy in the treatment of acute venous thromboembolism (VTE) and was associated with significantly less bleeding. This study evaluated their comparative effectiveness and safety in routine clinical practice. A matched-cohort design and data from four U.S. private health care claims databases were employed. Study population comprised patients who initiated outpatient treatment with apixaban versus warfarin (plus parenteral anticoagulant bridge therapy) within 30 days of their initial VTE episode; apixaban and warfarin patients were matched on age, characteristics of VTE episode, study database and propensity score. Major bleeding, clinically relevant non-major (CRNM) bleeding and recurrent VTE during the 180-day (maximum) follow-up period were compared using shared frailty models. During mean follow-up of 143 days among apixaban patients (n = 17,878) and 152 days among warfarin patients (n = 17,878), incidence proportions for apixaban versus warfarin, respectively, were 1.7% versus 2.3% for major bleeding, 7.0% versus 9.4% for CRNM bleeding and 2.3% versus 2.9% for recurrent VTE. In shared frailty models, risks of major bleeding (hazard ratio [HR] = 0.75, 95% confidence interval [CI] = 0.64-0.87), CRNM bleeding (HR = 0.77, 95% CI = 0.71-0.83) and recurrent VTE (HR = 0.80, 95% CI = 0.70-0.91) were lower for apixaban versus warfarin. In this large-scale evaluation of VTE patients receiving outpatient treatment with apixaban or warfarin in U.S. clinical practice, risks of major bleeding, CRNM bleeding and recurrent VTE were significantly lower among patients who received apixaban.

Oral anticoagulant dosing, administration, and storage: a cross-sectional survey of Canadian health care providers

Direct oral anticoagulant (DOAC) use is increasing worldwide. However, if not taken or prescribed correctly, DOACs have serious side effects. It is crucial that healthcare providers (HCPs) offer patients accurate information and counselling around DOACs, to optimize safe and effective use. To assess knowledge around oral anticoagulant indication, dosing, storage, and administration, an electronic survey was distributed to HCPs across Canada from June to August 2017, with 18 questions on the practical use of oral anticoagulants. A total of 191 responses were received: 100 from nurse practitioners, 42 from pharmacists, 27 from Hematologists, 5 from Thrombosis specialists, 4 from internists, 9 from residents and fellows, and 2 each from family physicians and registered nurses. Only 51 (26.7%) of the respondents correctly identified all the approved indications for warfarin and 4 DOACs. Only 101 (52.9%) correctly identified that DOACs are not approved for treatment of heparin-induced thrombocytopenia, cerebral sinus venous thrombosis, or mechanical prosthetic valves. 112 (58.6%) felt comfortable or very comfortable prescribing oral anticoagulants. Half of the respondents knew that dabigatran should not be crushed, however only 85 (44.5%) knew that it should not be exposed to moisture. 94 (49%) knew that higher dose rivaroxaban should be taken with food. The results of our study demonstrate that there are important knowledge gaps around HCPs' practical understanding of oral anticoagulants. Future research should focus on educational interventions to improve HCPs' knowledge around indications, dosing, storage, and administration, with the goal of enhancing patient safety.

Rivaroxaban Versus Warfarin and Risk of Post-Thrombotic Syndrome Among Patients with Venous Thromboembolism

BACKGROUND

The effectiveness of rivaroxaban to reduce post-thrombotic syndrome in patients with venous thromboembolism is largely unknown. We compared rates of post-thrombotic syndrome in patients given rivaroxaban versus warfarin in a cohort of patients with incident venous thromboembolism receiving routine clinical care.

METHODS

We linked Danish nationwide registries to identify all patients with incident venous thromboembolism who were new users of rivaroxaban or warfarin and compared rates of post-thrombotic syndrome using an inverse probability of treatment-weighting approach to account for baseline confounding.

RESULTS

We identified 19,957 oral anticoagulation-naive patients with incident venous thromboembolism treated with warfarin or rivaroxaban (mean age, 64 years; 48% were female, 45.5% had pulmonary embolism). The propensity-weighted rate of post-thrombotic syndrome at 3 years follow-up was 0.53 incidents per 100 person-years with rivaroxaban versus 0.55 per 100 person-years with warfarin, yielding a hazard rate of 0.88 (95% confidence interval, 0.66-1.17). This association remained consistent across types of venous thromboembolism (deep venous thrombosis vs pulmonary embolism, and provoked vs unprovoked venous thromboembolism) and when censoring patients with recurrent venous thromboembolism.

CONCLUSIONS

In this clinical practice setting, rivaroxaban was associated with lower but statistically nonsignificant rates of post-thrombotic syndrome, which did not appear to be mediated only by an effect on recurrent venous thromboembolism.