Periprocedural management of antithrombotic therapy and use of bridging anticoagulation

Prevention of the post thrombotic syndrome with anticoagulation: a narrative review

The post thrombotic syndrome (PTS) is chronic venous insufficiency secondary to a prior deep vein thrombosis (DVT). It is the most common complication of VTE and, while not fatal, it can lead to chronic, unremitting symptoms as well as societal and economic consequences. The cornerstone of PTS treatment lies in its prevention after DVT. Specific PTS preventative measures include the use of elastic compression stockings (ECS) and pharmacomechanical catheter directed thrombolysis (PCDT). However, the efficacy of these treatments has been questioned by large RCTs. So far, anticoagulation, primarily prescribed to prevent DVT extension and recurrence, appears to be the only unquestionably effective treatment for the prevention of PTS. In this literature review we present pathophysiological, biological, radiological and clinical data supporting the efficacy of anticoagulants to prevent PTS and the possible differential efficacy among available classes of anticoagulants (vitamin K antagonists (VKA), low molecular weight heparins (LMWHs) and direct oral anticoagulants (DOACs)). Data suggest that LMWHs and DOACs are superior to VKAs, but no head-to-head comparison is available between DOACs and LMWHs. Owing to their potentially greater anti-inflammatory properties, LMWHs could be superior to DOACs. This finding may be of interest particularly in patients with extensive DVT at high risk of moderate to severe PTS, but needs to be confirmed by a dedicated RCT.

Improved Benefit Risk Profile of Rivaroxaban in a Subpopulation of the MAGELLAN Study

Acutely ill medical patients are at risk of venous thromboembolism (VTE) and VTE-related mortality during hospitalization and posthospital discharge, but widespread adoption of extended thromboprophylaxis has not occurred. We analyzed a subpopulation within the MAGELLAN study of extended thromboprophylaxis with rivaroxaban to reevaluate the benefit risk profile. We identified 5 risk factors for major and fatal bleeding after a clinical analysis of the MAGELLAN study and analyzed efficacy and safety with these patients excluded (n = 1551). Risk factors included: active cancer, dual antiplatelet therapy at baseline, bronchiectasis/pulmonary cavitation, gastroduodenal ulcer, or bleeding within 3 months before randomization. We evaluated efficacy, safety, and benefit risk using clinically comparable endpoints in the subpopulation. At day 10, rivaroxaban was noninferior to enoxaparin (relative risk [RR] = 0.82, 95% confidence interval [CI] = 0.58-1.15) and at day 35 rivaroxaban was significantly better than enoxaparin/placebo (RR = 0.68, 95% CI = 0.53-0.88) in reducing VTE and VTE-related death. Major bleeding was reduced at day 10 (RR = 2.18, 95% CI = 1.07-4.44 vs 1.19, 95% CI = 0.54-2.65) and at day 35 (2.87, 95% CI = 1.60-5.15 vs 1.48, 95% CI = 0.77-2.84) for MAGELLAN versus this subpopulation, respectively. The benefit risk profile was favorable in this subpopulation treated for 35 days, with the number needed to treat ranging from 55 to 481 and number needed to harm from 455 to 1067 for all pairwise evaluations. Five exclusionary criteria defined a subpopulation of acutely ill medical patients with a positive benefit risk profile for in-hospital and extended thromboprophylaxis with rivaroxaban.

The current landscape of treatment options for venous thromboembolism: a focus on novel oral anticoagulants

BACKGROUND

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is a major cause of morbidity, mortality, and healthcare expenditure. Anticoagulant therapy is recommended for at least 3 months in patients with acute VTE to prevent recurrence. Conventional anticoagulants are associated with inherent limitations including route of administration, required monitoring and dose adjustments, potential for food-drug and drug-drug interactions, unpredictable pharmacokinetics and pharmacodynamics, and possible severe adverse events.

SCOPE

This manuscript reviews the pharmacology of the novel oral anticoagulants (NOACs), and analyzes the differences in phase 3 clinical trial designs, outcomes, and specific patient populations investigated for the treatment of acute and prevention of secondary VTE.

METHODS

A literature search was performed in PubMed using the key words dabigatran, apixaban, rivaroxaban, edoxaban, and venous thromboembolism in PubMed. The search included all years, English language, and peer-reviewed articles relating to phase 3 clinical trials, subanalyses, and meta-analyses of these NOACs for the treatment of acute VTE and secondary prevention.

FINDINGS

NOACs have demonstrated comparable efficacy and comparable or superior safety in large, randomized clinical trials in the treatment and prevention of VTE compared with conventional therapy. New oral anticoagulants, including the direct thrombin (dabigatran etexilate) and direct factor Xa inhibitors (rivaroxaban, apixaban, and edoxaban), have advantages over conventional agents such as oral administration at fixed doses, predictable pharmacokinetics and pharmacodynamics, minimal potential for food-drug and drug-drug interactions, and lack of required monitoring.

CONCLUSIONS

NOACs offer additional oral anticoagulation treatment options for patients with VTE.

The use of oral anticoagulants for the treatment of venous thromboembolic events in an ED

Venous thromboembolism (VTE) is a disease spectrum that ranges from deep vein thrombosis (DVT) to pulmonary embolism (PE). Rapid diagnosis and treatment of VTE by emergency care providers are critical for decreasing patient mortality, morbidity, and the incidence of recurrent events. Recent American College of Chest Physicians guidelines recommend initial treatment with unfractionated heparin, low-molecular weight heparin, or fondaparinux overlapped with warfarin for a minimum of 5 days for the treatment of VTE in most cases. Warfarin monotherapy is thereafter continued for 3, 6, or 12 months. These guidelines were published before the approval of target-specific oral anticoagulants (TSOACs), and they have yet to be updated to reflect these new treatment options. For some patients, TSOACs, which act by directly inhibiting factor IIa or factor Xa, may provide safer, more convenient alternatives to warfarin. Their advantages include ease of use, reduced monitoring requirements, and lower bleeding risk than traditional therapy. Additionally, clinical trials have established noninferiority of TSOACs to warfarin for the prevention of recurrent VTE. These trials have demonstrated that TSOACs exhibit similar or lower bleeding rates, particularly intracranial bleeding rates compared with warfarin. Anticoagulation therapy with TSOACs may allow early discharge or outpatient management options for low-risk patients with DVT and PE. This review addresses the importance of early diagnosis and treatment of VTE, outcomes of VTE risk assessment, key efficacy and safety data from phase 3 clinical trials for the various TSOACs for the treatment of DVT and PE, and the corresponding considerations for clinical practice.