Comparative safety and effectiveness of rivaroxaban versus VKAs in patients with venous thromboembolism

Safety and Effectiveness of Direct Oral Anticoagulants Versus Warfarin in Patients with Venous Thromboembolism using Real-World Data: A Systematic Review and Meta-Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have shown comparable efficacy and a superior safety profile in clinical trials for patients with venous thromboembolism (VTE). However, further study is needed to assess DOACs' effectiveness and safety compared to warfarin in a real-world context. Thus, this meta-analysis compares the effectiveness and safety of warfarin and DOACs in patients with VTE.

METHOD

A systematic review of the literature using PubMed and EMBASE was conducted from inception until June 2024. We examined observational studies that compared safety and effectiveness between DOACs and warfarin when used in treating VTE and reported adjusted hazard ratios (HRs) and/or odds ratios (ORs) for recurrent VTE, major bleeding, clinically relevant non-major bleeding, gastrointestinal bleeding, intracranial hemorrhage, and death from any cause. We then estimated the pooled effect using the random-effects model for meta-analysis.

RESULTS

A total of 25 studies were included in the current meta-analysis. DOAC therapy was associated with significantly lower risks of recurrent VTE (HR 0.76, 95% confidence interval [CI] 0.69-0.85), major bleeding (HR 0.77, 95% CI 0.72-0.83), clinically relevant non-major bleeding (HR 0.82, 95% CI 0.77-0.88), and gastrointestinal bleeding (HR 0.75, 95% CI 0.68-0.83) compared to warfarin. However, no statistically significant difference was observed in all-cause mortality between the two groups (HR 0.96, 95% CI 0.83-1.10).

CONCLUSION

This meta-analysis found that DOACs are associated with a significant reduction in VTE recurrence in addition to the known favorable safety profile when compared 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.

The protective effect of rivaroxaban with or without aspirin on inflammation, oxidative stress, and platelet reactivity in isoproterenol-induced cardiac injury in rats

Coronary artery diseases are principal sources of mortality and disability in global human population. Progressively, rivaroxaban is being evaluated for the prevention of atherosclerotic thrombi, particularly with anti-platelet agents. Hence, the current report aimed to investigate the cardioprotective effect of rivaroxaban on isoproterenol (ISO)-induced cardiac injury model in rats and the possible synergistic effect when combined with aspirin. Male Wistar rats were randomly assigned into five different groups. Cardiac injury was induced by subcutaneous injection of ISO (85 mg/kg) for 2 consecutive days. Rat tail bleeding time was performed prior to sacrifice. Cardiac enzymes, platelet activity, inflammatory, and oxidative stress biomarkers levels were measured using enzyme-linked immunoassay (ELISA). Pre-administration of rivaroxaban alone and on combination with aspirin prevented ISO-induced increase in cardiac thiobarbituric acid reactive substances (TBARS), interleukin 6 (IL-6), and thromboxane B2 (TXB2) levels. Moreover, a significant prolongation of bleeding time was demonstrated among aspirin, rivaroxaban, and aspirin plus rivaroxaban treated groups. On the other hand, the combination treatment of aspirin plus rivaroxaban showed no marked difference in these biomarkers and bleeding time relative to either drug administered separately. However, a prominent decrease of cardiac 6-keto prostaglandin F1α (6-Keto-PGF1α) level was displayed in the combination treatment when compared with ISO and rivaroxaban-treated groups, whereas no significant improvement was seen in cardiac glycoprotein V (GPV) levels except in aspirin-treated group. The study results demonstrated that rivaroxaban decreases cardiac oxidative stress, inflammation, and platelets reactivity. However, the addition of rivaroxaban to aspirin did not seem to show synergistic antioxidant, anti-inflammatory, or antiplatelet effect.

Pooled Analysis of Rivaroxaban therapy for acute venous thromboembolism in FIRST registry, SWIVTER and DRESDEN NOAC registry

Background

The direct factor Xa inhibitor rivaroxaban is approved for the treatment of venous thromboembolism (VTE), based on the results of large phase III trials.

Objectives

To confirm rivaroxaban's effectiveness and safety in routine clinical care of patients with VTE.

Methods

Data were obtained from prospective, noninterventional registries: the FIRST registry (United Kingdom), DRESDEN NOAC registry (Germany), and SWIVTER (Switzerland). Baseline characteristics of these registries and effectiveness and safety outcome rates for the FIRST and DRESDEN NOAC registries were compared.

Results

A total of 1841 rivaroxaban-treated patients with acute VTE (57.9% male, 76.6% deep vein thrombosis [DVT]; 23.4% pulmonary embolism ± DVT; median age, 61 years) were included: 1217 from the FIRST registry, 418 from the DRESDEN NOAC registry, and 206 from SWIVTER. Median time between VTE diagnosis and initiation of rivaroxaban was 1.4 ± 1.81 days (25th-75th percentile 1-1; range, 0-15 days). On-treatment outcome rates for the FIRST and DRESDEN NOAC registries were 0.74 per 100 patient-years (95% confidence interval [CI], 0.35-1.54) versus 0.96 per 100 patient-years (95% CI, 0.46-2.01) for VTE recurrence; 1.16 per 100 patient years (95% CI, 0.64-2.09) versus 2.51 per 100 patient-years (95% CI, 1.58-3.98) for ISTH major bleeding and 1.69 per 100 patient-years (95% CI, 1.21-2.35) versus 1.73 per 100 patient-years (95% CI, 1.27-2.36) for all-cause mortality (intention-to-treat analysis), respectively.

Conclusion

Overall treatment outcomes were consistent with the results of the phase III rivaroxaban trials in VTE treatment, indicating that the use of rivaroxaban offers acceptable treatment results also in routine care. However, we observed significant differences in patient characteristics and management patterns across Switzerland, the United Kingdom, and Germany, limiting direct comparisons of unadjusted outcome event rates between registries.

Effectiveness and Safety of Nonvitamin K Oral Anticoagulants Rivaroxaban and Apixaban in Patients with Venous Thromboembolism: A Meta-Analysis of Real-World Studies

Background

Rivaroxaban and apixaban are the most widely used nonvitamin K oral anticoagulants (NOACs) in patients with venous thromboembolism (VTE). This meta-analysis evaluates the effectiveness and safety of both NOACs versus standard of care (SoC) in real-world practice.

Methods

Real-world evidence (RWE) studies were identified through a systematic literature review conducted between January 2012 and July 2020, using Embase, MEDLINE, and the websites of cardiological, hematological, and oncological associations. Eligible RWE studies recruited adult patients with deep vein thrombosis and/or pulmonary embolism and presented a comparison between rivaroxaban and apixaban versus SoC, consisting either of vitamin K antagonists, heparins, or combinations thereof. Hazard ratios (HRs) for the comparison between NOACs and SoC were extracted from the relevant studies or estimated based on the reported binary data. The between-treatment contrasts were reported as HRs with associated 95% confidence intervals.

Results

A total of 65 RWE studies were identified and considered relevant for the meta-analysis. Compared with SoC, both rivaroxaban and apixaban were associated with reduced risks of recurrent VTE and a lower rate of major bleeding events. Patients treated with rivaroxaban were at a lower risk of all-cause death compared with those receiving SoC (HR = 0.56 [0.39-0.80]), while evidence for apixaban from the identified studies was insufficient to demonstrate a statistically significant change in mortality (HR = 0.66 [0.30-1.47]).

Conclusion

This analysis indicates that in real-world practice, rivaroxaban and apixaban are associated with a lower risk of recurrent VTE and major bleeding events compared with SoC. Survival benefit in patients treated with rivaroxaban was also observed.

Different Risk Profiles of European Patients Using Direct Oral Anticoagulants or Vitamin K Antagonists: a Rapid Review

Purpose of Review

We investigated the risk profiles of patients using direct oral anticoagulants (DOAC) or vitamin K antagonists (VKA) in European cohort studies to estimate the importance of potential (measured or unmeasured) confounding factors in analyses comparing these drugs. We searched MEDLINE and EMBASE (2008–2018) for relevant studies and extracted information on age, sex, comorbidity, Charlson comorbidity index, HAS-BLED score (assessing risk of bleeding) and CHA2DS2-VASc score (assessing risk of stroke).

Recent Findings

Overall, 66 studies with 2,808,757 patients were included. Most patients were from France (37%), Denmark (24%) and Germany (23%). In 56 studies (85%), the focus was on patients with atrial fibrillation. Of the 43 studies comparing DOAC with VKA users, 33% reported a higher and 16% a lower age of DOAC compared with VKA users. The mean age varied by about 1 year in most of these studies. Rivaroxaban was used in the widest age range. Patients with DOAC more often had a history of stroke or bleedings, and patients with VKA more often had a history of diabetes, renal failure, cancer, heart failure or other heart diseases. Most studies did not observe differences regarding the HAS-BLED score or the CHA2DS2-VASc score between groups.

Summary

Our review suggests that there are relevant differences in the risk profiles of DOAC versus VKA users and between users of individual DOACs. Reported HAS-BLED or CHA2DS2-VASc scores did not reflect these differences. These patterns require careful consideration in the interpretation of observational studies comparing the effectiveness and the risks of these drugs, also when comparing the results of studies conducted in different countries.

Anticoagulation in Italian patients with venous thromboembolism and thrombophilic alterations: findings from START2 register study

BACKGROUND

Randomised control trials have assessed the efficacy and safety of direct oral anticoagulants in the prophylaxis and treatment of venous thromboembolism (VTE). Positive but limited results have been reported in patients with inherited thrombophilia. Using an Italian, multicentre, prospective registry of consecutive patients presenting with symptomatic, acute VTE, we aimed to assess which factors are involved in making the choice of the drug that best fits the patient's risk profile in a large real-world setting of VTE patients.

MATERIALS AND METHODS

We investigated 4,866 VTE patients who took oral anticoagulants in the period between 2012 and April 2018 to prevent a new thromboembolic episode.

RESULTS

The large majority of patients who underwent thrombophilic screening, regardless of the results obtained, were prescribed direct oral anticoagulants rather than conventional anticoagulant therapy (p<0.001). During anticoagulation, bleeding events occurred more frequently in patients on conventional anticoagulant therapy (4.2%) than in those receiving direct oral anticoagulants (1.8%) and an increase in bleeding events was observed in patients who tested positive at the thrombophilic screening. Overall, a higher number of recurrent VTE was observed in patients not screened for thrombophilia (n=36; 1.7%) than in those screened (n=20; 0.7%; adjusted odds ratio: 2.2; 95% confidence interval: 1.2-4.1).

DISCUSSION

The present data confirm previous findings from other post-marketing registries and suggest that the choice of oral anticoagulation is strongly driven by patients' characteristics and VTE manifestations. Factors leading to the prescription of thrombophilic screening may identify a patient with a lower risk of VTE recurrence during anticoagulation.

A Multicenter Prospective Observational Cohort Study to Investigate the Effectiveness and Safety of Rivaroxaban in Japanese Venous Thromboembolism Patients (The J'xactly Study)

BACKGROUND

There is insufficient real-world data on the current status of Japanese patients with venous thromboembolism (VTE) or its treatment and prevention with rivaroxaban.Methods and Results:In this multicenter, prospective, observational study conducted in Japan, 1,039 patients with acute symptomatic/asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) with or without DVT prescribed rivaroxaban were enrolled at 152 institutions and observed for a median of 21.3 months. Mean age was 68.0±14.7 years, mean body weight was 60.3±14.1 kg, 59.0% were females, and 19.0% had active cancer. Incidences of recurrence or aggravation of symptomatic VTE (primary effectiveness outcome) and major bleeding (principal safety outcome) were 2.6% and 2.9% per patient-year, respectively. These outcomes did not differ between patients with DVT and those with PE (primary effectiveness outcome: 2.6% vs. 2.5% per patient-year, P=0.810; principal safety outcome: 3.5% vs. 2.4% per patient-year, P=0.394). The incidence of composite clinically relevant events, including recurrence or aggravation of symptomatic VTE, acute coronary syndrome, ischemic stroke, all-cause death, or major bleeding events, was 9.2% per patient-year. Multivariate analysis revealed that male sex, being underweight, having active cancer, chronic heart and lung disease, and previous stroke were independent determinants for composite clinically relevant events.

CONCLUSIONS

In Japanese clinical practice, a single-drug approach with rivaroxaban was demonstrated to be a valuable treatment for a broad range of VTE patients.

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.

Wild P, H. Prochaska J. Telemedicine-Based Specialized Care Improves the Outcome of Anticoagulated Individuals with Venous Thromboembolism-Results from the thrombEVAL Study

Venous thromboembolism (VTE) is a life-threatening disease with risk of recurrence. Oral anticoagulation (OAC) with vitamin K antagonists (VKA) is effective to prevent thromboembolic recurrence. We aimed to investigate the quality of OAC of VTE patients in regular medical care (RMC) compared to a telemedicine-based coagulation service (CS). The thrombEVAL study (NCT01809015) is a prospective, multi-center study to investigate OAC treatment (recruitment: January 2011-March 2013). Patients were evaluated using clinical visits, computer-assisted personal interviews, self-reported data and laboratory measurements according to standard operating procedures. Overall, 360 patients with VTE from RMC and 254 from CS were included. Time in therapeutic range (TTR) was higher in CS compared to RMC (76.9% (interquartile range [IQR] 63.2-87.1%) vs. 69.5% (52.3-85.6%), p < 0.001). Crude rate of thromboembolic events (rate ratio [RR] 11.33 (95% confidence interval [CI] 1.85-465.26), p = 0.0015), clinically relevant bleeding (RR 6.80 (2.52-25.76), p < 0.001), hospitalizations (RR 2.54 (1.94-3.39), p < 0.001) and mortality under OAC (RR 5.89 (2.40-18.75), p < 0.001) were consistently higher in RMC compared with CS. Patients in RMC had higher risk for primary outcome (clinically relevant bleedings, thromboembolic events and mortality, hazard ratio [HR] 5.39 (95%CI 2.81-10.33), p < 0.0001), mortality (HR 5.54 (2.22-13.84), p = 0.00025), thromboembolic events (HR 6.41 (1.51-27.24), p = 0.012), clinically relevant bleeding (HR 5.31 (1.89-14.89), p = 0.0015) and hospitalization (HR 1.84 (1.34-2.55), p = 0.0002). Benefits of CS care were still observed after adjusting for comorbidities and TTR. In conclusion, anticoagulation quality and outcome of VTE patients undergoing VKA treatment was significantly better in CS than in RMC. Patients treated in CS had lower rates of adverse events, hospitalizations and lower mortality. CS was prognostically relevant, beyond providing advantages of improved international ratio (INR) monitoring.

Validation of venous thromboembolism diagnoses in patients receiving rivaroxaban or warfarin in The Health Improvement Network

Purpose

To describe the effect that validation of venous thromboembolism (VTE) coded entries in the health improvement network (THIN) has on incidence rates of VTE among a cohort of rivaroxaban/warfarin users.

Methods

Among 36 701 individuals with a first prescription for rivaroxaban/warfarin between 2012 and 2015, we performed a two‐step VTE case identification process followed by a two‐step case validation process involving manual review of patient records. A valid case required a coded entry for VTE at some point after their first rivaroxaban/warfarin prescription with evidence of referral/hospitalization either as a coded entry or entered as free text. Positive predictive values (PPVs) with 95% confidence intervals (CIs) were calculated using validated cases as the gold standard. Incidence rates were calculated per 1000 person‐years with 95% CIs.

Results

We identified 2166 patients with a coded entry of VTE after their initial rivaroxaban/warfarin prescription; incidence rate of 45.31 per 1000 person‐years (95% CI: 43.49‐47.22). After manual review of patient records including the free text, there were 712 incident VTE cases; incidence rate of 14.90 per 1000 person‐years (95% CI: 13.85‐16.02). The PPV for coded entries of VTE alone was 32.9%, and the PPV for coded entries of VTE with a coded entry of referral/hospitalization was 39.8%; this increased to 69.6% after manual review of coded clinical entries in patient records.

Conclusions

Among rivaroxaban/warfarin users in THIN, valid VTE case identification requires manual review of patient records including the free text to prevent outcome misclassification and substantial overestimation of VTE incidence rates.

Impact of concomitant antiplatelet therapy on the efficacy and safety of direct oral anticoagulants for acute venous thromboembolism: Systematic review and meta-analysis

BACKGROUND

Direct oral anticoagulants (DOACs) are recommended over vitamin K antagonists (VKAs) for the treatment of venous thromboembolism (VTE). Concomitant antiplatelet therapy may potentiate the antithrombotic effects of DOACs.

OBJECTIVES

We evaluated the impact of concomitant antiplatelet therapy on the efficacy and safety of DOACs.

PATIENTS/METHODS

MEDLINE, EMBASE, and Clinicaltrial.gov were searched for randomized controlled trials of DOACs for the treatment of acute VTE. The efficacy outcome was symptomatic recurrent VTE and VTE-related death; the primary safety outcome was major bleeding.

RESULTS

Six randomized controlled trials included 26 924 patients of whom 3550 (13.2%) received concomitant antiplatelet therapy, mainly aspirin (67.7%). Concomitant antiplatelet therapy did not reduce the incidence of recurrent VTE and VTE-related death with any oral anticoagulant (odds ratio [OR] 1.17; 95% confidence interval [CI], 0.92-1.48), with DOACs (OR 1.21; 95% CI, 0.86-1.71), or VKAs alone (OR 1.16; 95% CI, 0.77-1.73). Compared with no antiplatelet therapy, concomitant antiplatelet therapy was associated with a higher risk of major bleeding in patients with any oral anticoagulant (OR 1.79; 95% CI, 1.22-2.63), DOACs (OR 1.89; 95% CI, 1.04-3.44), or VKAs (OR 1.73; 95% CI, 1.16-2.59). In patients receiving concomitant antiplatelet therapy, there were no statistically significant differences in efficacy or safety outcomes with DOACs or VKAs (OR 0.99; 95% CI, 0.64-1.51, and OR 0.68; 95% CI, 0.32-1.45, respectively).

CONCLUSIONS

Concomitant use of antiplatelet therapy with oral anticoagulants does not appear to affect the risk of recurrent VTE and increases the risk of major bleeding.

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.

Risk of Major Gastrointestinal Bleeding With New vs Conventional Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over whether use of non-vitamin K antagonist oral anticoagulants (NOACs) associates with increased risk of major gastrointestinal bleeding (GIB) compared with conventional therapies (such as vitamin K antagonists or anti-platelet agents). We performed a systematic review and meta-analysis of data from randomized controlled trials and high-quality real-world studies.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov Website databases (through Oct 12, 2018) for randomized controlled trials and high-quality real-world studies that reported major GIB events in patients given NOACs or conventional therapy. Relative risks (RRs) for randomized controlled trials and adjusted hazard ratios (aHRs) for real-world studies were calculated separately using random-effects models.

RESULTS

We analyzed data from 43 randomized controlled trials (183,752 patients) and 41 real-world studies (1,879,428 patients). The pooled major rates of GIB for patients on NOACs (1.19%) vs conventional treatment (0.92%) did not differ significantly (RR from randomized controlled trials, 1.09; 95% CI, 0.91-1.31 and aHR from real-world studies, 1.02; 95% CI, 0.94-1.10; P_interaction=.52). Rivaroxaban, but not other NOACs, was associated with an increased risk for major GIB (RR from randomized controlled trials, 1.39; 95% CI, 1.17-1.65 and aHR from real-world studies, 1.14; 95% CI, 1.04-1.23; P_interaction = .06). Analyses of subgroups, such as patients with different indications, dosage, or follow-up time, did not significantly affect results. Meta-regression analysis failed to detect any potential confounding to impact the primacy outcome.

CONCLUSIONS

In a systematic review and meta-analysis of data from randomized controlled trials and real-world studies, we confirmed that there is no significant difference in risk of major GIB between patients receiving NOACs vs conventional treatment. Rivaroxaban users had a 39% increase in risk for major GIB.

Use of rivaroxaban in patients attending a hematology unit in clinical practice

Aim: To determine drug persistence and rates of events among patients treated with rivaroxaban in a hematology unit. Methods: Retrospective study of patients that started treatment with rivaroxaban, in the hematology unit of a tertiary hospital. Results: A total of 161 patients were included, of whom 83.9% had atrial fibrillation and 11.2% venous thromboembolism, and 76.4% of patients were taking rivaroxaban 20 mg, 22.4% 15 mg and 1.2% 10 mg. After a follow-up of 1.8 ± 1.1 years, only four patients (2.5%) discontinued treatment. Rates of thromboembolic events, major bleeding/clinically relevant nonmajor bleeding and intracranial hemorrhage were 1.1, 2.8, 0.3 events per 100 patient-years, respectively. Conclusion: In patients attended in a hematology unit, medication persistence was high, and the incidence of outcomes low.

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.

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.

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.

Venous thromboembolism therapy with rivaroxaban in daily-care patients: Results from the Dresden NOAC registry

The effectiveness and safety of acute venous thromboembolism (VTE) treatment with rivaroxaban, demonstrated in phase-III trials, needs to be confirmed in daily care. To confirm the positive results of phase-III VTE treatment trials with rivaroxaban in daily care, we used data from the ongoing, prospective, non-interventional Dresden NOAC Registry. For this analysis, only patients with acute VTE who started rivaroxaban within 14days after diagnosis of VTE and who were enrolled within these 14days were evaluated with regard to patient characteristics, treatment persistence and clinical outcomes. Between December 1st 2011 and 30th September 2016, 418 patients with acute VTE and rivaroxaban treatment were enrolled. During rivaroxaban treatment (median rivaroxaban exposure 206d; median follow-up 862d) rates of recurrent VTE and ISTH major bleeding were 1.9% and 3.8%, respectively. At 6months. 58.3% of patients were still taking rivaroxaban, 28.2% had a scheduled end of treatment, 7.2% were switched to other anticoagulants, 1.7% had withdrawn their consent and the remaining 3.6% of patients had unplanned complete discontinuation of anticoagulation. After permanent discontinuation of rivaroxaban, 20 patients experienced a recurrent VTE (7 pulmonary embolism±deep vein thrombosis, 13 deep vein thrombosis) with a mean time between last intake of rivaroxaban and VTE recurrence of 374.3±247.6days (range 28-927d). In daily care patients with acute VTE, rivaroxaban demonstrated high effectiveness with acceptable major bleeding rates. Initial dosing was according to label in over 90% of patients and persistence to rivaroxaban therapy was adequate with low rates of unplanned complete discontinuation.

All-Cause Mortality Risk with Direct Oral Anticoagulants and Warfarin in the Primary Treatment of Venous Thromboembolism

Oral anticoagulants used for the primary treatment of venous thromboembolism (VTE) include warfarin and the more recently introduced direct oral anticoagulants (DOACs), including rivaroxaban, apixaban, dabigatran and edoxaban. Information on the comparative safety of these medications in routine clinical practice is lacking. We identified patients with diagnoses for VTE and prescriptions for oral anticoagulants using claims data from a large U.S. insurance database from 2012 to 2017. Marginal structural logistic models were used to examine associations between type of oral anticoagulant and risk of all-cause mortality. Of 62,431 enrolees in this analysis, 51% were female and the mean age was 61.9 years. Initial oral anticoagulant prescriptions were for warfarin (n = 35,704), rivaroxaban (n = 21,064) and apixaban (n = 5,663). A total of 1,791 deaths occurred within 6 months of the initial oral anticoagulant prescription. Risk of all-cause mortality was not associated with having a prescription for warfarin versus any DOAC or between any head-to-head DOAC comparisons. Also, associations generally did not vary when stratified by VTE type, sex, age, co-morbidities (including renal disease) or anti-platelet medication use. In this observational study, the associations with all-cause mortality comparing DOACs versus warfarin agree with results from previous clinical trials and observational studies, while the associations for head-to-head DOAC comparisons provide new information on the comparative safety of DOACs. Our findings suggest that other criteria such as patient preference, cost, recurrent VTE risk or bleeding risk should be used when determining the choice of anticoagulant for the primary treatment of VTE.

Anticoagulation Resumption After Intracerebral Hemorrhage

Purpose of review

Decision-making on resuming oral anticoagulant (OAC) after intracerebral hemorrhage (ICH) evokes significant debate among clinicians. Such patients have been excluded from randomized clinical trials. This review article provides a comprehensive summary of the evidence on anticoagulation resumption after ICH.

Recent findings

OAC resumption does not increase the risk of recurrent ICH and can also reduce the risk of all-cause mortality. OAC cessation exposes patients to a significantly higher risk of thromboembolism, which could be reduced by resumption. The optimal timing of anticoagulation resumption after ICH is still unknown. Both early (< 2 weeks) and late (> 4 weeks) resumption should be reached only after very careful assessment of risks for ICH recurrence and thromboembolism. The introduction of new oral anticoagulants and other interventions, such as left atrial appendage closure, has provided some patients with more alternatives.

Summary

Given the lack of high-quality evidence to guide clinical decision-making, clinicians must carefully balance the risks of thromboembolism and recurrent ICH in individual patients. We propose a management approach which would facilitate the decision-making process on whether anticoagulation is appropriate, as well as when and how to restart anticoagulation after ICH.

Strengths and weaknesses of 'real-world' studies involving non-vitamin K antagonist oral anticoagulants

Randomised controlled trials (RCTs) provide the reference standard for comparing the efficacy of one therapy or intervention with another. However, RCTs have restrictive inclusion and exclusion criteria; thus, they are not fully representative of an unselected real-world population. Real-world evidence (RWE) studies encompass a wide range of research methodologies and data sources and can be broadly categorised as non-interventional studies, patient registries, claims database studies, patient surveys and electronic health record studies. If appropriately designed, RWE studies include a patient population that is far more representative of unselected patient populations than those of RCTs, but they do not provide a robust basis for comparing treatment strategies. RWE studies can have very large sample sizes, can provide information on treatments in patient groups that are usually excluded from RCTs, are generally less expensive and quicker than RCTs, and can assess a broad range of outcomes. Limitations of RWE studies can include low internal validity, lack of quality control surrounding data collection and susceptibility to multiple sources of bias for comparing outcomes. RWE studies can complement the findings from RCTs by providing valuable information on treatment practices and patient characteristics among unselected patients. This information is necessary to guide treatment decisions and for reimbursement and payment decisions. RWE studies have been extensively applied in the postmarketing approval assessment of non-vitamin K antagonist oral anticoagulants since 2010. However, the benefits, costs, limitations and methodological challenges associated with the different types of RWE must be considered carefully when interpreting the findings.

What have we learned from real-world NOAC studies in venous thromboembolism treatment?

Venous thromboembolism (VTE) remains a substantial clinical and health-economic burden worldwide and effective anticoagulant treatment is necessary immediately after VTE is suspected to reduce short- and long-term VTE related morbidity and mortality. For decades, low molecular weight heparin (LMWH), fondaparinux and Vitamin K antagonists (VKAs) have been the standard of anticoagulant therapy for VTE patients but these treatment options had clinically relevant drawbacks and limitations. The introduction of non-VKA oral anticoagulants (NOACs) that specifically inhibit either thrombin or factor Xa have resolved many of these drawbacks because these new compounds exhibit a rapid onset and offset of action, fewer food and drug interactions and a predictable anticoagulant effect. All NOACs have successfully completed their respective phase-III trial programs consisting of many large randomized controlled trials, leading to approval for acute VTE treatment around the world. Nevertheless, their introduction into daily care practice is challenging and a careful evaluation of the effectiveness and safety of NOACs in less selected cohorts outside carefully monitored clinical trials is essential. This review introduces the different types of real-world evidence (RWE) and explores the available data for VTE treatment with NOACs, based on a literature search using the key words "venous thromboembolism" or "VTE" in combination with "NOAC", "DOAC", "apixaban", "dabigatran", "edoxaban" and "rivaroxaban" on June 30; 2017, followed by data extraction from studies that reported real-world outcome data for VTE treatment with NOACs, although available evidence is almost exclusively limited to rivaroxaban.

Comparative safety of direct oral anticoagulants and warfarin in venous thromboembolism: multicentre, population based, observational study

Objective To determine the safety of direct oral anticoagulant (DOAC) use compared with warfarin use for the treatment of venous thromboembolism.Design Retrospective matched cohort study conducted between 1 January 2009 and 31 March 2016.Setting Community based, using healthcare data from six jurisdictions in Canada and the United States.Participants 59 525 adults (12 489 DOAC users; 47 036 warfarin users) with a new diagnosis of venous thromboembolism and a prescription for a DOAC or warfarin within 30 days of diagnosis.Main outcome measures Outcomes included hospital admission or emergency department visit for major bleeding and all cause mortality within 90 days after starting treatment. Propensity score matching and shared frailty models were used to estimate adjusted hazard ratios of the outcomes comparing DOACs with warfarin. Analyses were conducted independently at each site, with meta-analytical methods used to estimate pooled hazard ratios across sites.Results Of the 59 525 participants, 1967 (3.3%) had a major bleed and 1029 (1.7%) died over a mean follow-up of 85.2 days. The risk of major bleeding was similar for DOAC compared with warfarin use (pooled hazard ratio 0.92, 95% confidence interval 0.82 to 1.03), with the overall direction of the association favouring DOAC use. No difference was found in the risk of death (pooled hazard ratio 0.99, 0.84 to 1.16) for DOACs compared with warfarin use. There was no evidence of heterogeneity across centres, between patients with and without chronic kidney disease, across age groups, or between male and female patients.Conclusions In this analysis of adults with incident venous thromboembolism, treatment with DOACs, compared with warfarin, was not associated with an increased risk of major bleeding or all cause mortality in the first 90 days of treatment.Trial registration Clinical trials NCT02833987.

Temporal trends in initiation of VKA, rivaroxaban, apixaban and dabigatran for the treatment of venous thromboembolism - A Danish nationwide cohort study

Danish nationwide registries were used to investigate temporal trends in initiation of rivaroxaban or apixaban or dabigatran versus vitamin K antagonists (VKA) in patients with venous thromboembolism (VTE). Patients treated with one of the NOACs (rivaroxaban, dabigatran, apixaban) or VKA were identified between February 2012 and September 2016. A total of 19,578 patients were included of which 10,844 (55.4%) were treated with VKA and 8,734 (44.6%) were treated with NOACs (rivaroxaban 7,572, apixaban 1,066, and dabigatran 96). Temporal trends showed a decrease in the initiation of VKA (p-value for decreasing trend, p < 0001) and an increase in the initiation of rivaroxaban and apixaban (p-value for increasing trend, p < 0001). By September 2016, 12%, 70%, 16%, and 2% of patients with VTE were initiated on VKA, rivaroxaban, apixaban, and dabigatran. Patients with previous VTE, chronic kidney disease, liver disease, cancer, and thrombophilia were more likely to be initiated on VKA compared with one of the NOACs. In conclusion the initiation of rivaroxaban and apixaban is increasing significantly over time in patients with VTE. Patients with previous VTE, chronic kidney disease, liver disease, cancer, and thrombophilia were more likely to be initiated on VKA compared with rivaroxaban or apixaban.

NOACs for treatment of venous thromboembolism in clinical practice

Randomised controlled trials have provided important information on the efficacy and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) for treatment of venous thromboembolism (VTE), leading to registration and increasing use in clinical practice. Many questions remain to be answered, and observational studies are often more suitable for answering "real-world" questions than randomised controlled trials. Patient satisfaction, quality of life, and adherence and persistence in clinical practice with the drug regimen can only be assessed with an open-label design. Evaluation of risk for long-term sequelae of the disease requires much longer follow-up than is possible in registration trials. Treatment patterns and utilisation of health care resources can be assessed from observations in the clinical practice setting. We will review published as well as currently active observational studies with NOACs in VTE, with or without a comparator anticoagulant. These studies are based on cohorts of different sizes, registries, or administrative health care databases. We will also discuss some limitations in analysis and interpretation of observational studies.