Venous thromboembolism is the obstruction of a vein or veins by a blood clot in the blood stream . Venous thrombosis specifically refers to the formation or presence of a blood clot within a vein .

Vascular Medicine

Venous thromboembolism

Q: Open questions

Uncertainty remains regarding the true difference in bleeding risk between apixaban and rivaroxaban for treating acute venous thromboembolism . The efficacy of direct oral anticoagulants is also uncertain for conditions such as left ventricular thrombus, catheter-associated deep vein thrombosis, and cerebral venous sinus thrombosis . Additionally, research is ongoing to evaluate the benefits and harms of statins in the secondary prevention of recurrent venous thromboembolic disease in general populations aged over 70 years .

Deep vein thrombosis and venous thromboembolism: anticoagulant choice, duration, factor XI inhibitors and cancer-associated thrombosis.

Also called VTE, DVT, deep vein thrombosis

Sources: 12 new papers · 5 key papers · updated Oct 20, 2026

Overview

Unverified · drafted by AI from the sources cited below

Definition

Venous thromboembolism is the obstruction of a vein or veins by a blood clot in the blood stream.1

Diagnosis and risk stratification

Ultrasound, computed tomography angiography, and venography are used for the multimodal diagnosis of severe deep vein thrombosis complications.1 The VTE-PREDICT risk score utilizes 14 patient characteristics to predict 5-year risks of recurrent venous thromboembolism and clinically relevant bleeding.2 In emergency surgery, the Caprini Risk Score evaluated in 267 patients demonstrated an AUC of 0.82 for predicting postoperative venous thromboembolism, identifying a threshold of 5.5 scores with 81% sensitivity and 72% specificity.3

Treatment

For most patients, direct oral anticoagulants are preferred over vitamin K antagonists for venous thromboembolism treatment.1 However, in patients with thrombotic antiphospholipid syndrome, direct oral anticoagulants are associated with increased odds of subsequent arterial thrombotic events (OR: 5.43; 95% CI: 1.87-15.75; P < 0.001) compared to vitamin K antagonists.2 In a trial of 2760 patients comparing apixaban to rivaroxaban for acute venous thromboembolism, a primary bleeding event occurred in 44 of 1345 patients (3.3%) in the apixaban group.3 Early pharmacologic venous thromboembolism prophylaxis can be initiated within 48 h of admission for intensive care unit patients with intracerebral hemorrhage.4 In pediatric patients with cardiac disease, a trial of 167 children found treatment-emergent adverse events occurred in 46.8% (51/109) treated with edoxaban and 41.4% (24/58) treated with standard of care.5

Open questions

Uncertainty remains regarding the true difference in bleeding risk between apixaban and rivaroxaban for treating acute venous thromboembolism.1 The efficacy of direct oral anticoagulants is also uncertain for conditions such as left ventricular thrombus, catheter-associated deep vein thrombosis, and cerebral venous sinus thrombosis.2 Additionally, research is ongoing to evaluate the benefits and harms of statins in the secondary prevention of recurrent venous thromboembolic disease in general populations aged over 70 years.3

How this page is built

A clinical question appears here only when its condition matches this topic, an outcome and a comparator were extracted from the studies, at least two studies and a patient count are on file, and the certainty is low or higher.

Supports benefit, no benefit shown, and mixed describe the direction of the measured effect. No benefit shown means the evidence does not support a benefit. It is not a finding of harm. Too little evidence means the question did not clear that bar.

Study count, RCT count, and patient count are separate. The patient total adds only studies that are linked into a study family and whose sample size is not flagged as implausible. A reversal is listed only when at least one randomized trial sits on each side of the change.

The overview is drafted from the guideline recommendations, trials, papers, and questions on this page, and every sentence has to cite one of them. It stays unverified until an NPI-verified clinician or a Synapse admin approves it. Approving records that person's name.