Effectiveness and safety of rivaroxaban and warfarin in patients with unprovoked venous thromboembolism: a propensity-matched nationwide cohort study.

Deep vein thrombosis (DVT) and pulmonary embolism are collectively known as venous thromboembolism (VTE), which is a common vascular disease and a major cause of morbidity and mortality worldwide. We compare effectiveness and safety of rivaroxaban versus warfarin in a prospective cohort of routine care patients with incident unprovoked VTE. In this propensity-matched cohort study, we linked nationwide Danish health registries to identify all patients with a first hospital diagnosis of unprovoked VTE who were new users of rivaroxaban or warfarin. Excluded patients included those who had not been residents in Denmark for at least 1 year before VTE diagnosis, patients with outpatient VTE diagnosis only, patients with other indications for oral anticoagulation treatment, patients with previous experience of oral anticoagulation, patients who did not have a prescription for rivaroxaban or warfarin within 7 days of VTE, and patients who redeemed prescriptions for both rivaroxaban and warfarin, or other oral anticoagulants. Primary effectiveness outcome was recurrent VTE and primary safety outcome was major bleeding. We used propensity matching and Cox regression to compare rates of the outcomes with rivaroxaban versus standard treatment. From Dec 9, 2011, to Feb 28, 2016, we identified 29 963 patients with incident VTE. After exclusion, we identified 1734 propensity-matched patients given rivaroxaban (1751 before propensity matching) and 2945 propensity-matched patients given warfarin. The rate of recurrent VTE at 6 months' follow-up was 9·9 incidents per 100 person-years with rivaroxaban versus 13·1 incidents per 100 person-years with warfarin, yielding a hazard ratio (HR) of 0·74 (95% CI 0·56-0·96). The rate of major bleeding was 2·4 per 100 person-years at 6 months in rivaroxaban users versus 2·0 in warfarin users (HR 1·19, 95% CI 0·66-2·13). In this clinical practice setting, rivaroxaban in patients with unprovoked VTE was associated with reduced risk of recurrent VTE compared with standard treatment, without compromising safety. Obel Family Foundation.

Larsen TB ，Skjøth F ，Kjældgaard JN ，Lip GYH ，Nielsen PB ，Søgaard M ... -  《Lancet Haematology》

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

Coleman CI ，Bunz TJ ，Turpie AGG 《-》

Effectiveness and safety of rivaroxaban versus warfarin in patients with unprovoked venous thromboembolism: A propensity-score weighted administrative claims cohort study.

In phase III trials, rivaroxaban demonstrated non-inferiority over enoxaparin/warfarin to prevent recurrent venous thromboembolism (VTE), with a reduction of major bleeding. However, compared to provoked VTE, the risk-benefit ratio of rivaroxaban may be different for patients with unprovoked VTE. In a retrospective claims data analysis using US MarketScan claims from 1/2012 to 12/2016, we included adults with a primary diagnosis of VTE newly-initiated on rivaroxaban or warfarin within 30-days of the incident VTE and with ≥12-months of continuous insurance benefits prior to the VTE (baseline). Patients with provoked VTE, a claim for anticoagulation during baseline or who redeemed prescriptions for ≥1 oral anticoagulant were excluded. Our primary outcomes were recurrent VTE and major bleeding at 6-months using an intention-to-treat (ITT) analysis. Three-month ITT and 12-month on-treatment (30-day permissible gap) analyses were also performed. Inverse probability-of-treatment weights based on propensity-scores and Cox regression were used to compare outcomes. We identified 10,489 rivaroxaban users and 26,364 warfarin users with incident unprovoked VTE. At 6-months, rivaroxaban was associated with a hazard ratio (HR) of 0.60 (95% confidence interval [CI] = 0.54-0.67) for recurrent VTE (number-needed-to-treat: 59; 95%CI 49-76) and a HR = 0.80 (95% CI = 0.66-0.98) for major bleeding versus warfarin. Our findings remained consistent in the 3- and 12-month analyses. Consistent with the results from the EINSTEIN phase-III trials, findings of our routine practice study suggest that, in patients with unprovoked VTE, rivaroxaban has the potential to reduce both the risk of major bleeding and recurrent VTE compared to warfarin.

Coleman CI ，Peacock WF ，Bunz TJ ，Beyer-Westendorf J ... -  《-》

Effectiveness and safety of outpatient rivaroxaban versus warfarin for treatment of venous thromboembolism in patients with a known primary hypercoagulable state.

Screening for primary hypercoagulable states (PHSs) in venous thromboembolism (VTE) patients was not mandated in the EINSTEIN trials; and therefore, few patients with a known PHS were available for analysis. We sought to assess the effectiveness and safety of rivaroxaban versus warfarin for treatment of VTE in patients with a known PHS. Using MarketScan claims data from 1/2012-9/2015, we identified adults with a primary diagnosis of VTE during a hospitalization/emergency department visit (the index event), with ≥180-days of continuous insurance coverage prior to the index event, a documented diagnosis for a PHS and newly-initiated as an outpatient on rivaroxaban or warfarin within 30-days of the index VTE. Rivaroxaban and warfarin users were 1:1 propensity-score matched. Balance between cohorts was evaluated by inspecting standardized differences for baseline covariates (<0.1 considered well-balanced). Patients were followed up to 12-months from the index event or until occurrence of an endpoint, switch/discontinuation of index oral anticoagulation or insurance disenrollment. Rates of recurrent VTE and major bleeding were compared using Cox regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). We matched 403 rivaroxaban and 403 warfarin patients with VTE and a known PHS. All baseline covariates had a standardized difference < 0.1. Rivaroxaban use was associated with a non-significant reduction in recurrent VTE (HR = 0.70, 95%CI = 0.33-1.49) and major bleeding (HR = 0.55, 95%CI = 0.16-1.86) versus warfarin. In routine practice, the effectiveness and safety of rivaroxaban versus warfarin in VTE patients with a known PHS appears to be similar to that observed in the EINSTEIN trial program.

Coleman CI ，Turpie AGG ，Bunz TJ ，Baker WL ，Beyer-Westendorf J ... -  《-》

Association of Type of Oral Anticoagulant Dispensed With Adverse Clinical Outcomes in Patients Extending Anticoagulation Therapy Beyond 90 Days After Hospitalization for Venous Thromboembolism.

Pawar A ，Gagne JJ ，Gopalakrishnan C ，Iyer G ，Tesfaye H ，Brill G ，Chin K ，Bykov K ... -  《-》