Risk for Recurrent Venous Thromboembolism and Bleeding With Apixaban Compared With Rivaroxaban: An Analysis of Real-World Data.

BACKGROUND: Apixaban and rivaroxaban are replacing vitamin K antagonists for the treatment of venous thromboembolism (VTE) in adults; however, head-to-head comparisons remain limited. OBJECTIVE: To assess the effectiveness and safety of apixaban compared with rivaroxaban in patients with VTE. DESIGN: Retrospective new-user cohort study. SETTING: U.S.-based commercial health care insurance database from 1 January 2015 to 30 June 2020. PARTICIPANTS: Adults with VTE who were newly prescribed apixaban or rivaroxaban. MEASUREMENTS: The primary effectiveness outcome was recurrent VTE, a composite of deep venous thrombosis and pulmonary embolism. The primary safety outcome was a composite of gastrointestinal and intracranial bleeding. RESULTS: Of 49 900 eligible patients with VTE, 18 618 were new users of apixaban and 18 618 were new users of rivaroxaban. Median follow-up was 102 days (25th, 75th percentiles: 30, 128 days) among apixaban and 105 days (25th, 75th percentiles: 30, 140 days) among rivaroxaban users. After propensity score matching, apixaban (vs. rivaroxaban) was associated with a lower rate for recurrent VTE (hazard ratio, 0.77 [95% CI, 0.69 to 0.87]) and bleeding (hazard ratio, 0.60 [CI, 0.53 to 0.69]). The absolute reduction in the probability of recurrent VTE with apixaban versus rivaroxaban was 0.006 (CI, 0.005 to 0.011) within 2 months and 0.011 (CI, 0.011 to 0.013) within 6 months of initiation. The absolute reduction in the probability of gastrointestinal and intracranial bleeding with apixaban versus rivaroxaban was 0.011 (CI, 0.010 to 0.011) within 2 months and 0.015 (CI, 0.013 to 0.015) within 6 months of initiation. LIMITATION: Short follow-up. CONCLUSION: In this population-based cohort study, patients with VTE who were new users of apixaban had lower rates for recurrent VTE and bleeding than new users of rivaroxaban. PRIMARY FUNDING SOURCE: None.

Effectiveness and Safety of Direct Oral Anticoagulants Versus Warfarin in Patients With Valvular Atrial Fibrillation : A Population-Based Cohort Study.

BACKGROUND: Direct oral anticoagulants (DOACs) are increasingly used in place of warfarin, but evidence about their effectiveness and safety in patients with valvular atrial fibrillation (AF) remains limited. OBJECTIVE: To assess the effectiveness and safety of DOACs compared with warfarin in patients with valvular AF. DESIGN: New-user retrospective propensity score-matched cohort study. SETTING: U.S.-based commercial health care database from 1 January 2010 to 30 June 2019. PARTICIPANTS: Adults with valvular AF who were newly prescribed DOACs or warfarin. MEASUREMENTS: The primary effectiveness outcome was a composite of ischemic stroke or systemic embolism. The primary safety outcome was a composite of intracranial or gastrointestinal bleeding. RESULTS: Among a total of 56 336 patients with valvular AF matched on propensity score, use of DOACs (vs. warfarin) was associated with lower risk for ischemic stroke or systemic embolism (hazard ratio [HR], 0.64 [95% CI, 0.59 to 0.70]) and major bleeding events (HR, 0.67 [CI, 0.63 to 0.72]). The results for the effectiveness and safety outcomes remained consistent for apixaban (HRs, 0.54 [CI, 0.47 to 0.61] and 0.52 [CI, 0.47 to 0.57], respectively) and rivaroxaban (HRs, 0.74 [CI, 0.64 to 0.86] and 0.87 [CI, 0.79 to 0.96], respectively); with dabigatran, results were consistent for the major bleeding outcome (HR, 0.81 [CI, 0.68 to 0.97]) but not for effectiveness (HR, 1.03 [CI, 0.81 to 1.31]). LIMITATION: Relatively short follow-up; inability to ascertain disease severity. CONCLUSION: In this comparative effectiveness study using practice-based claims data, patients with valvular AF who were new users of DOACs had lower risks for ischemic stroke or systemic embolism and major bleeding than new users of warfarin. These data may be used to guide risk-benefit discussions regarding anticoagulant choices for patients with valvular AF. PRIMARY FUNDING SOURCE: None.

Quality of direct oral anticoagulant prescribing in elderly patients with non-valvular atrial fibrillation: results from a large urban health system.

Non-valvular atrial fibrillation (NVAF) is common in older adults. Oral anticoagulation is indicated to reduce the risk of stroke and systemic embolism, but it also poses a risk of bleeding, particularly in the elderly. Direct oral anticoagulants (DOACs) provide an alternative to warfarin and their use in the treatment of AF is growing. We conducted a retrospective cohort study to assess the quality of DOAC prescribing in elderly patients with NVAF in a large academic health system and to compare practice with consensus best practice recommendations. We searched the electronic medical record for patients ≥ 65 years of age who were newly initiated on a DOAC for AF from January 2013 through December 2015. Patient and provider characteristics, baseline laboratory investigations, concomitant medications, and interval to first follow-up were recorded. 192 patients met eligibility criteria. The most commonly prescribed DOACs were rivaroxaban (65%) and apixaban (26%). Despite consensus recommendations that patients have a baseline creatinine, complete blood cell count, and coagulation studies prior to DOAC initiation, these tests were not performed in 18, 31, and 67% of patients, respectively. Consensus recommendations also suggest a follow-up visit within 1 month of DOAC initiation. However, only 39% of patients had a return visit within 6 weeks and 43% did not have follow-up within 12 weeks. DOAC prescribing in elderly patients with NVAF frequently fell short of quality standards. Interventions to enhance the quality of DOAC prescribing in this high-risk population are needed.

How I manage patients with anticoagulation-associated bleeding or urgent surgery.

Antithrombotic treatment puts patients at risk of major bleeding. Fast and adequate response to anticoagulant-associated bleeding may not only stop the bleeding but prevent severe complications. However, practical treatment algorithms to guide physicians in emergency situations are lacking. Important principles that arise from management of bleeding in general are (a) implementation of an in-house algorithm, (b) rapid identification and treatment of the bleeding source, (c) adequate fluid resuscitation, (d) consideration of the application of tranexamic acid and (e) appropriate coagulation testing. We present an algorithm for anticoagulant-associated bleeding and urgent surgery, derived from available data and recommendations, and implemented at our institution. Decisions regarding reversal agents or postponing surgery are based on two questions: the occurrence of a life-threatening bleed or urgent indication for surgery, and the presence of a relevant drug level. Immediate application of reversal agents is suggested if the clinical situation is urgent and laboratory test results are delayed or unavailable. A relevant anticoagulant drug level is required in all other cases. We discuss appropriate laboratory assays for all commonly available anticoagulants, report respective target ranges or expected values, discuss time intervals before surgery, and present critical cut-off values to be used as decision criteria. Specific and unspecific reversal agents for all anticoagulants including the direct oral anticoagulants will be presented. We aim to provide practical guidance for physicians in emergency situations. In addition, we summarise and discuss available experimental and clinical data as well as recommendations provided by scientific societies, authorities and manufacturers.

Controversies in the treatment of immune thrombocytopenia.

PURPOSE OF REVIEW: We address three current controversies in management of immune thrombocytopenia (ITP): Should asymptomatic children with newly diagnosed ITP and severe thrombocytopenia be treated? Does intensification of up-front therapy in adults with newly diagnosed ITP impact long-term outcomes? Is splenectomy still the second-line treatment of choice in adults with chronic ITP? RECENT FINDINGS: Severe bleeding is rare in children with ITP. There is little evidence that the platelet count predicts or that treatment prevents severe bleeding in this population. Intensified treatment with high-dose dexamethasone and rituximab in adults with newly diagnosed ITP is associated with improved platelet responses at 6 and 12 months but greater toxicity compared with standard therapy. Rituximab and thrombopoietin receptor agonists have emerged as suitable alternatives to splenectomy for second-line management of adults with chronic ITP. SUMMARY: We generally observe children with newly diagnosed ITP and mild or no bleeding symptoms, irrespective of platelet count. We do not routinely use intensified up-front therapy in adults with newly diagnosed ITP. We discuss the advantages and disadvantages of splenectomy, rituximab, and thrombopoietin receptor agonists with our patients and make a joint decision that takes into consideration age, comorbidities, lifestyle, values, preferences, and financial considerations.

Monitoring and reversal of direct oral anticoagulants.

Although the direct oral anticoagulants (DOACs) do not require routine monitoring and reduce bleeding compared with warfarin, there are special circumstances in which laboratory measurement or reversal of their anticoagulant effect may be indicated. The dilute thrombin time and ecarin-based assays are able to quantify dabigatran across a broad range of concentrations, but are not widely available. A normal thrombin time excludes clinically relevant levels and a normal activated partial thromboplastin time probably excludes excess levels of dabigatran. Factor Xa inhibitors may be quantified with an anti-Xa assay calibrated with drug-specific standards. A normal prothrombin time probably excludes excess levels of rivaroxaban and edoxaban, but not apixaban. Patients with minor and moderate DOAC-associated bleeding can be treated with supportive care and general hemostatic measures. Nonspecific reversal agents (eg, prothrombin complex concentrate, activated prothrombin complex concentrate) are of unproven benefit, carry a risk of thrombosis, and should be reserved for severe bleeding. Specific reversal agents, such as idarucizumab (a monoclonal antibody fragment that binds dabigatran) and andexanet alfa (a recombinant factor Xa variant that binds factor Xa inhibitors but lacks coagulant activity), are in clinical development.