Case fatality of bleeding and recurrent venous thromboembolism during, initial therapy with direct oral anticoagulants: A systematic review

Mortality Rate in Upper Gastrointestinal Bleeding Associated with Anti-Thrombotic Therapy Before and During Covid-19 Pandemic

INTRODUCTION

During the last few years, a progressive higher proportion of patients have had upper gastrointestinal bleeding (UGIB) related to antithrombotic therapy. The introduction of direct oral anticoagulant (DOAC) and COVID-19 pandemic may change the incidence, mortality, and follow-up, especially in patients at high risk of bleeding.

PATIENTS AND METHODS

We studied the use of anti-thrombotic therapy (AT) in patients with upper gastrointestinal bleeding for 5 years (January 2017-December 2021) including Covid-19 pandemic period (March 2020-December 2021). We analyzed mortality rate, rebleeding rate and need for transfusion in patients with AT therapy compared with those without AT therapy and risk factors for mortality, and also the incidence of gastrointestinal bleeding in patients admitted for COVID-19 infection.

RESULTS

A total of 824 patients were admitted during Covid-19 pandemic period and 1631 before pandemic period; a total of 426 cases of bleeding were recorded in patients taking antithrombotic therapy and the frequency of antithrombotic therapy in patients with UGIB was higher in pandemic period (24.39% versus 13.8%). Unadjusted mortality was 12.21%, similar with patients with no antithrombotic treatment but age-adjusted mortality was 9.62% (28% lower). The rate of endoscopy was similar but fewer therapeutic procedures were required. Mean Hb level was 10% lower, and more than 60% of patients required blood transfusion.

CONCLUSION

Mortality was similar compared with patients with no antithrombotic therapy, fewer therapeutic endoscopies were performed and similar rebleeding rate and emergency surgery were noted. Hb level was 10% lower and a higher proportion of patients required blood transfusions. Mortality was higher in DOAC treatment group compared with VKA patients but with no statistical significance. The rate of upper gastrointestinal bleeding in Covid-19 positive hospitalized cases was 0.58%. The mortality risk in multivariate analysis was associated with GB score, with no endoscopy performed, with obscure and variceal bleeding and with LMWH versus VKA therapy.

Deep Venous Thrombosis

Venous thromboembolism (VTE) is the third most common cardiovascular disorder, affecting up to 5% of the population. VTE commonly manifests as lower-extremity deep venous thrombosis (DVT) or pulmonary embolism. Half of these events are associated with a transient risk factor and may be preventable with prophylaxis. Direct oral anticoagulants are effective and safe and carry a lower risk for bleeding than vitamin K antagonists. Many patients with VTE will have a chronic disease requiring long-term anticoagulation. Postthrombotic syndrome affects 25% to 40% of patients with DVT and significantly impacts function and quality of life.

Major hemorrhage and mortality in COVID-19 patients on therapeutic anticoagulation for venous thromboembolism

We observed multiple fatal intracranial hemorrhages shortly after initiating therapeutic anticoagulation for treatment of venous thromboembolism (VTE) in COVID-19 patients suggesting increased anticoagulation risk associated with COVID-19. The objective of this study is to quantify risk of major hemorrhage in hospitalized COVID-19 patients on therapeutic anticoagulation for deep venous thrombosis (DVT) or pulmonary embolism (PE). Hospitalized patients with COVID-19 receiving therapeutic anticoagulation for DVT, PE or both at four New York City hospitals were evaluated for hemorrhagic complications. These were categorized as major (including fatal) or clinically relevant non-major according to the criteria of the International Society of Thrombosis and Haemostasis. Hemorrhagic complications were correlated with clinical and laboratory data, ICD-10 code diagnoses and type of anticoagulation treatment. Minor hemorrhages were excluded. Major/clinically relevant hemorrhages occurred in 36 of 170 (21%) hospitalized COVID-19 patients being treated with therapeutic anticoagulation for VTE including 4 (2.4%) fatal hemorrhages. Hemorrhage was 3.4 times more likely with unfractionated heparin 27/76 (36%) compared to 8/81 (10%) with low molecular weight heparin (p = 0.002). Multivariate analysis showed that major hemorrhage was associated with intubation (p = 0.04) and elevated serum LDH (p < 0.001) and low fibrinogen (p = 0.05). Increased risk of hemorrhagic complications in treating VTE in hospitalized COVID-19 patients should be considered especially when using unfractionated heparin, in intubated patients, with low fibrinogen and/or elevated LDH. Checking serum fibrinogen and LDH before initiating therapeutic anticoagulation and monitoring coagulation parameters frequently may reduce bleeding complications.

Cost-Effectiveness Analysis of Direct Oral Anticoagulants Versus Vitamin K Antagonists for Venous Thromboembolism in China

Background: The drug therapy of venous thromboembolism (VTE) presents a significant economic burden to the health-care system in low- and middle-income countries. To understand which anticoagulation therapy is most cost-effective for clinical decision-making , the cost-effectiveness of apixaban (API) versus rivaroxaban (RIV), dabigatran (DAB), and low molecular weight heparin (LMWH), followed by vitamin K antagonist (VKA), in the treatment of VTE in China was assessed. Methods: To access the quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs), a long-term cost-effectiveness analysis was constructed using a Markov model with 5 health states. The Markov model was developed using patient data collected from the Xijing Hospital from January 1, 2016 to January 1, 2021. The time horizon was set at 30 years, and a 6-month cycle length was used in the model. Costs and ICERs were reported in 2020 U.S. dollars. One-way sensitivity analysis and probabilistic sensitivity analysis (PSA) were used to test the uncertainties. A Chinese health-care system perspective was used. Results: In the base case, the data of 231 VTE patients were calculated in the base case analysis retrospectively. The RIV group resulted in a mean VTE attributable to 95% effective treatment. API, DAB, and VKA have a negative ICER (-187017.543, -284,674.922, and -9,283.339, respectively) and were absolutely dominated. The Markov model results confirmed this observation. The ICER of the API and RIV was negative (-216176.977), which belongs to the absolute inferiority scheme, and the ICER value of the DAB and VKA versus RIV was positive (110,577.872 and 836,846.343). Since the ICER of DAB and VKA exceeds the threshold, RIV therapy was likely to be the best choice for the treatment of VTE within the acceptable threshold range. The results of the sensitivity analysis revealed that the model output varied mostly with the cost in the DAB on-treatment therapy. In a probabilistic sensitivity analysis of 1,000 patients for 30 years, RIV has 100% probability of being cost-effective compared with other regimens when the WTP is $10973 per QALY. When WTP exceeded $148,000, DAB was more cost-effective than RIV. Conclusions: Compared with LMWH + VKA and API, the results proved that RIV may be the most cost-effective treatment for VTE patients in China. Our findings could be helpful for physicians in clinical decision-making to select the appropriate treatment option for VTE.

Which patients are at high risk of recurrent venous thromboembolism (deep vein thrombosis and pulmonary embolism)?

Recurrent venous thromboembolism (VTE, or deep vein thrombosis and pulmonary embolism) is associated with mortality and long-term morbidity. The circumstances in which an index VTE event occurred are crucial when personalized VTE recurrence risk is assessed. Patients who experience a VTE event in the setting of a transient major risk factor (such as surgery associated with general anesthesia for >30 minutes) are predicted to have a low VTE recurrence risk following discontinuation of anticoagulation, and limited-duration anticoagulation is generally recommended. In contrast, those patients whose VTE event occurred in the absence of risk factors or who have persistent risk factors have a higher VTE recurrence risk. Here, we review the literature surrounding VTE recurrence risk in a range of clinical conditions. We describe gender-specific risks, including VTE recurrence risk following hormone- and pregnancy-associated VTE events. Finally, we discuss how the competing impacts of VTE recurrence and bleeding have shaped international guideline recommendations.

Bleeding Risk Assessment in Patients with Venous Thromboembolism

The recommended treatment for patients with venous thromboembolism (VTE) is anticoagulation for at least 3 months. However, anticoagulant treatment increases the risk of bleeding, and patients at high risk for major bleeding might benefit from treatment discontinuation. In this review, we discuss strategies for assessing bleeding risk and compare different bleeding risk tools. Bleeding risk assessment is best viewed as a continuous approach with varying challenges throughout the acute and chronic phase. At diagnosis, bleeding risk factors must be identified and reversible risk factors treated or modified. After initial treatment, repeated bleeding risk assessment is crucial for the decision on extended/long-term anticoagulation. Current clinical prediction models (e.g., HAS-BLED, RIETE, or VTE-BLEED scores) are externally validated tools with relevant differences in specificity and sensitivity, which can aid in clinical decision-making. Unfortunately, none of the current bleeding risk assessment tools has been investigated in clinical trials and provides evidence to withhold anticoagulation treatment based on the score. Nevertheless, the HAS-BLED or RIETE score can be used to identify patients at high risk for major bleeding during the initial treatment phase, while the VTE-BLEED score might be used to identify patients at low risk for bleeding and, therefore, to safely administer extended/long-term anticoagulation for secondary thromboprophylaxis. As clinical prediction scores still lack predictive value, future research should focus on developing biomarker-based risk assessment models.

Which patients are at high risk of recurrent venous thromboembolism (deep vein thrombosis and pulmonary embolism)?

Recurrent venous thromboembolism (VTE, or deep vein thrombosis and pulmonary embolism) is associated with mortality and long-term morbidity. The circumstances in which an index VTE event occurred are crucial when personalized VTE recurrence risk is assessed. Patients who experience a VTE event in the setting of a transient major risk factor (such as surgery associated with general anesthesia for >30 minutes) are predicted to have a low VTE recurrence risk following discontinuation of anticoagulation, and limited-duration anticoagulation is generally recommended. In contrast, those patients whose VTE event occurred in the absence of risk factors or who have persistent risk factors have a higher VTE recurrence risk. Here, we review the literature surrounding VTE recurrence risk in a range of clinical conditions. We describe gender-specific risks, including VTE recurrence risk following hormone- and pregnancy-associated VTE events. Finally, we discuss how the competing impacts of VTE recurrence and bleeding have shaped international guideline recommendations.

ETNA-VTE Europe: Benefits and risks of venous thromboembolism treatment using edoxaban in the first 3 months

INTRODUCTION

Edoxaban had a positive risk-benefit ratio for the treatment of venous thromboembolism (VTE) compared to conventional therapy with warfarin. The objective of this analysis of the ongoing ETNA-VTE Europe study was to assess the real-world benefits and risks of edoxaban during the first 3 months of treatment, the highest risk period for further VTE events.

METHODS

ETNA-VTE Europe is a prospective, non-interventional, post-authorization study, conducted in eight European countries. Participants had initial or recurrent acute VTE (deep vein thrombosis [DVT] and/or pulmonary embolism [PE]) that occurred ≤2 weeks prior to enrolment and received edoxaban therapy.

RESULTS

The analysis set included 2672 patients (PE ± DVT, n = 1117; DVT only, n = 1555); mean age 62.9 ± 16.0 years, bodyweight 81.9 ± 17.4 kg, estimated glomerular filtration rate 95.4 ± 42.8 mL/min; 46.4% were female. Overall, 66.4% of patients (PE ± DVT, 68.5%; DVT-only, 64.8%) received heparin lead-in treatment for at least 5 days. Most patients (87.7%) received edoxaban at a dose of 60 mg once daily. Event rates at 3 months were: recurrent VTE 0.34% (n = 9), major bleeding 0.97% (n = 26), all-cause mortality 0.79% (n = 21). Rates were numerically higher in the PE ± DVT group compared with the DVT-only group (recurrent VTE, 0.45% (n = 5) versus 0.26% (n = 4); major bleeding, 1.34% (n = 15) versus 0.71% (n = 11); and all-cause mortality 1.16% (n = 13) versus 0.51% (n = 8)).

CONCLUSIONS

The results support the safety and effectiveness of edoxaban in a general VTE population during the most critical time period, the first 3 months. The outcomes of this study extend the principal efficacy and safety data on edoxaban into the routine clinical practice setting.

Outcomes of endovascular venous stenting in patients on direct oral anticoagulants and antiplatelet therapy at a tertiary referral center

BACKGROUND

Endovenous revascularization is the standard in the management of acute thrombotic, chronic post-thrombotic iliocaval or iliofemoral obstruction, and nonthrombotic iliac vein lesions. The purpose of this study is to describe our single-center experience of postprocedure anticoagulation and antiplatelet regimens used after endovenous revascularization for a variety of venous occlusive conditions.

METHODS

We conducted a retrospective analysis of 100 consecutive patients who underwent endovenous stenting for iliocaval or iliofemoral obstruction from January 1, 2014, to April 30, 2018. Patients treated with direct oral anticoagulants, warfarin, or low-molecular-weight heparin (LMWH) with or without antiplatelet therapy were identified. Demographic, procedural, patency, and follow-up data were collected. Stent patency was evaluated using duplex Doppler ultrasound examination or contrast venography.

RESULTS

Seventy-one of 100 patients were treated with direct oral anticoagulant therapy (DOAC). Sixteen (23%) were lost to follow-up, leaving 55 (77%) available for analysis. The mean follow-up was 14 months (range, 1-43 months) with 32 patients (58%) followed for 12 months or longer. Primary, primary-assisted, and secondary-assisted patency rates were 87%, 97%, and 98%, respectively, at 12 months. In the non-DOAC group (patients treated with warfarin or LMWH), these rates were 87%, 93%, and 95%, respectively, at 12 months. Antiplatelet therapy, including clopidogrel, aspirin, or both, was used in 53 of 55 patients in the DOAC cohort and 18 of 19 patients in the non-DOAC group.

CONCLUSIONS

Our-single center retrospective analysis demonstrates acceptable primary patency rates when using DOAC therapy compared with those treated with warfarin or LMWH.

Long-term treatment of venous thromboembolism

The most important decision in the long-term treatment of venous thromboembolism (VTE) is how long to anticoagulate. VTE provoked by a reversible risk factor, or a first unprovoked isolated distal deep vein thrombosis (DVT), generally should be treated for 3 months. VTE provoked by a persistent or progressive risk factor (eg, cancer), or a second unprovoked proximal DVT or PE, is generally treated indefinitely. First unprovoked proximal DVT or PE may be treated for 3 to 6 months or indefinitely. Male sex, presentation as PE (particularly if concomitant proximal DVT), a positive d-dimer test after stopping anticoagulation, an antiphospholipid antibody, low risk of bleeding, and patient preference favor indefinite anticoagulation. The type of indefinite anticoagulation is of secondary importance. Low-dose oral Xa inhibitors are convenient and are thought to have a lower risk of bleeding; they are less suitable if there is a higher risk for recurrence. For cancer-associated VTE, we now prefer full-dose oral Xa inhibitors over low-molecular-weight heparin, with gastrointestinal lesions being a relative contraindication. Graduated compression stockings are not routinely indicated after DVT, but are encouraged if there is persistent leg swelling or if a trial of stockings improves symptoms. Medications have a limited role in the treatment of postthrombotic syndrome. After PE, patients should have clinical surveillance for chronic thromboembolic pulmonary hypertension (CTEPH), with ventilation-perfusion scanning and echocardiography being the initial diagnostic tests if CTEPH is a concern. Patients with CTEPH and other symptomatic patients with extensive residual perfusion defects should be evaluated for endarterectomy, balloon pulmonary angioplasty, or vasodilator therapies.

High incidence of venous thromboembolism recurrence in patients with sickle cell disease

Previous reports show increased incidence of venous thromboembolism [VTE, deep-vein thrombosis (DVT) and pulmonary embolus (PE)] in sickle cell disease (SCD) patients. The incidence, time course, and risk factors for VTE recurrence have been less well described. We determined the cumulative incidence of first VTE recurrence and bleeding in a cohort of SCD patients with incident VTE. Risk factors for recurrence and bleeding were also determined using multivariable Cox regression models, adjusting for gender, race/ethnicity, era of incident VTE, location and hospitalization-associated status of incident VTE, and SCD-related complications. Results are presented as adjusted hazard ratios (HR) and 95% confidence intervals (CI). Among 877 SCD patients with an incident VTE, the 1-year and 5-year cumulative incidence of recurrence was 13.2% (95% CI 11.0%-15.5%) and 24.1% (95% CI 21.2%-27.1%). Risk factors for VTE recurrence included more severe SCD (HR = 2.41; CI: 1.67-3.47), lower extremity DVT as the incident event (HR = 1.64; CI: 1.17-2.30), and pneumonia/acute chest syndrome (HR = 1.68; CI: 1.15-2.45). The cumulative incidence of bleeding was 4.9% (CI 3.5%-6.4%) at 6 months and 7.9% (CI: 6.2%-9.8%) at 1 year. More severe SCD (HR = 1.61; CI: 1.11-2.35) was associated with bleeding. The high incidence of VTE recurrence in patients with SCD suggests that extended anticoagulation may be indicated; however, this must be weighed against a relatively high risk of bleeding. Prospective, randomized studies of anticoagulation in SCD patients with VTE are needed.

Genotype-guided versus standard vitamin K antagonist dosing algorithms in patients initiating anticoagulation

Variability in vitamin K antagonist (VKA) dosing is partially explained by genetic polymorphisms. We performed a meta-analysis to determine whether genotype-guided VKA dosing algorithms decrease a composite of death, thromboembolic events and major bleeding (pri-mary outcome) and improve time in therapeutic range (TTR). We searched MEDLINE, EMBASE, CENTRAL, trial registries and conference proceedings for randomised trials comparing genotype-guided and standard (non genotype-guided) VKA dosing algorithms in adults initiating anticoagulation. Data were pooled using a random effects model. Of the 12 included studies (3,217 patients), six reported all components of the primary outcome of mortality, thromboembolic events and major bleeding (2,223 patients, 87 events). Our meta-analysis found no significant difference between groups for the primary outcome (relative risk 0.85, 95 % confidence interval [CI] 0.54–1.34; heterogeneity X2=4.46, p=0.35, I2=10 %). Based on 10 studies (2,767 patients), TTR was significantly higher in the genotype-guided group (mean difference (MD) 4.31 %; 95 % CI 0.35, 8.26; heterogeneity X2=43.31, p< 0.001, I2=79 %). Pre-specified exploratory analyses demonstrated that TTR was significantly higher when geno-type-guided dosing was compared with fixed VKA dosing (6 trials, 997 patients: MD 8.41 %; 95 % CI 3.50,13.31; heterogeneity X2=15.18, p=0.01, I2=67 %) but not when compared with clinical algorithm-guided dosing (4 trials, 1,770 patients: MD –0.29 %; 95 % CI –2.48,1.90; heterogeneity X2=1.53, p=0.68, I2=0 %; p for interaction=0.002). In conclusion, genotype-guided compared with standard VKA dosing algorithms were not found to decrease a composite of death, thromboembolism and major bleeding, but did result in improved TTR. An improvement in TTR was observed in comparison with fixed VKA dosing algorithms, but not with clinical algorithms.

Reversal agents for use with direct and indirect anticoagulants

PURPOSE

The properties of three oral anticoagulant-specific reversal agents are reviewed, and guidance is presented to assist pharmacists in planning for the agents' introduction to the market.

SUMMARY

Idarucizumab, which received Food and Drug Administration approval in October 2015, is a humanized monoclonal antibody fragment that immediately neutralizes the anticoagulant effect of dabigatran, as evidenced by reduced unbound dabigatran concentrations and normalized coagulation tests. Preliminary Phase III trial results demonstrated a median maximum reversal of 100%, a median time to bleeding cessation of 11.4 hours, and normal intraoperative hemostasis in 92% of patients requiring anticoagulation reversal before an urgent procedure. Andexanet alfa is a factor Xa (FXa) decoy that binds to direct and indirect FXa inhibitors. In Phase III trials in healthy volunteers, andexanet alfa reduced anti-FXa activity by more than 90%, reduced the concentration of unbound direct FXa inhibitor, and inhibited thrombin generation. Ciraparantag is a reversal agent under development for reversal of anticoagulation with direct and indirect FXa inhibitors and certain factor IIa inhibitors; it exerts its effect through hydrogen bonding. Concerns for thromboembolic events directly related to administration of idarucizumab, andexanet alfa, or ciraparantag have not arisen. Pharmacists need to begin preparing for the introduction of these specific reversal agents through protocol development and provider education; in addition, pharmacy departments need to plan for procurement and storage. The specific reversal agents should be incorporated into antithrombotic stewardship or other clinical pharmacy programs for surveillance.

CONCLUSION

As agents that provide rapid reversal of direct oral anticoagulant activity become available, advance planning will help hospitals to optimize their use.

Prevention of thrombosis in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an acquired autoimmune condition characterized by thrombotic events, pregnancy morbidity, and laboratory evidence of antiphospholipid antibodies (aPL). Management of these patients includes the prevention of a first thrombotic episode in at-risk patients (primary prevention) and preventing recurrent thrombotic complications in patients with a history of thrombosis (secondary prevention). Assessment of thrombotic risk in these patients, balanced against estimated bleeding risks associated with antithrombotic therapy could assist clinicians in determining whether antithrombotic therapy is warranted. Thrombotic risk can be assessed by evaluating a patient's aPL profile and additional thrombotic risk factors. Although antithrombotic options for secondary prevention of venous thromboembolism (VTE) have been evaluated in clinical trials, studies in primary prevention of asymptomatic aPL-positive patients are needed. Primary prevention with aspirin may be considered in asymptomatic patients who have a high-risk aPL profile, particularly if additional risk factors are present. Secondary prevention with long-term anticoagulation is recommended based on estimated risks of VTE recurrence, although routine evaluation of thrombotic risk can assist in determining whether ongoing anticoagulation is warranted. Studies that stratify thrombotic risk in aPL-positive patients, and patients with APS evaluating antithrombotic and non-antithrombotic therapies will be useful in optimizing the management of these patients.

Idarucizumab, a Specific Reversal Agent for Dabigatran: Mode of Action, Pharmacokinetics and Pharmacodynamics, and Safety and Efficacy in Phase 1 Subjects

The direct oral anticoagulants (DOACs) provide a number of clinical advantages over vitamin K antagonists for the treatment of thromboembolism, including improved efficacy and safety, as well as no need for regular monitoring of anticoagulant effect. However, as with all anticoagulants, bleeding complications may occur, and anticoagulant reversal may be required in specific clinical situations, such as in patients experiencing spontaneous or traumatic bleeds, or in anticoagulated patients requiring emergency surgery or other invasive procedures. Therefore, several reversal agents for the DOACs are in development. This includes the specific reversal agent idarucizumab, which has been approved by the U.S. Food and Drug Administration and the European Medicines Agency for use in patients treated with dabigatran when urgent reversal of its anticoagulant effects is needed. Idarucizumab is a humanized monoclonal antibody fragment that binds with high affinity to free and thrombin-bound dabigatran, resulting in an almost irreversibly bound idarucizumab-dabigatran complex and thereby neutralizing dabigatran's anticoagulant activity. The reversal of the anticoagulant effects of dabigatran by idarucizumab has been demonstrated in animal bleeding models, in healthy volunteers with a range of ages and renal function, and in anticoagulated patients. In the phase 1 trials, at doses of 2 g or greater, idarucizumab resulted in immediate and complete reversal of the dabigatran anticoagulant effects and was well tolerated. In the absence of dabigatran, idarucizumab showed no effect on coagulation parameters or thrombin formation. These findings provide initial evidence that idarucizumab could provide a safe and effective means of reversing anticoagulant activity in patients treated with dabigatran in need of emergency surgery or in emergency bleeding situations.

Acute phase treatment of VTE: Anticoagulation, including non-vitamin K antagonist oral anticoagulants

The acute phase of venous thromboembolism (VTE) treatment focuses on the prompt and safe initiation of full-dose anticoagulation to decrease morbidity and mortality. Immediate management consists of resuscitation, supportive care, and thrombolysis for patients with haemodynamically significant pulmonary embolism (PE) or limb-threatening deep-vein thrombosis (DVT). Patients with contraindications to anticoagulants are considered for vena cava filters. Disposition for the acute treatment of VTE is then considered based on published risk scores and the patient's social status, as the first seven days carries the highest risk for VTE recurrence, extension and bleeding due to anticoagulation. Next, a review of: immediate and long-term bleeding risk, comorbidities (i. e. active cancer, renal failure, obesity, thrombophilia), medications, patient preference, VTE location and potential for pregnancy should be undertaken. This will help determine the most suitable anticoagulant for immediate treatment. The non-vitamin K antagonist oral anticoagulants (NOACs), including the factor Xa inhibitors apixaban, edoxaban and rivaroxaban as well as the direct-thrombin inhibitor dabigatran, are increasing the convenience of and options available for VTE treatment. Current options for immediate treatment include low-molecular-weight heparin (LMWH), unfractionated heparin (UFH), fondaparinux, apixaban, or rivaroxaban. LMWH or UFH may be continued as monotherapy or transitioned to treatment with a VKA, dabigatran or edoxaban. This review describes the upfront treatment of VTE and the evolving role of NOACs in the contemporary management of VTE.