Management of suspected and confirmed recurrent venous thrombosis while on anticoagulant therapy. What next?

Mechanisms of COVID-19 Associated Pulmonary Thrombosis: A Narrative Review

COVID-19, the infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is frequently associated with pulmonary thrombotic events, especially in hospitalized patients. Severe SARS-CoV-2 infection is characterized by a proinflammatory state and an associated disbalance in hemostasis. Immune pathology analysis supports the inflammatory nature of pulmonary arterial thrombi composed of white blood cells, especially neutrophils, CD3+ and CD20+ lymphocytes, fibrin, red blood cells, and platelets. Immune cells, cytokines, chemokines, and the complement system are key drivers of immunothrombosis, as they induce the damage of endothelial cells and initiate proinflammatory and procoagulant positive feedback loops. Neutrophil extracellular traps induced by COVID-19-associated “cytokine storm”, platelets, red blood cells, and coagulation pathways close the inflammation–endotheliopathy–thrombosis axis, contributing to SARS-CoV-2-associated pulmonary thrombotic events. The hypothesis of immunothrombosis is also supported by the minor role of venous thromboembolism with chest CT imaging data showing peripheral blood clots associated with inflammatory lesions and the high incidence of thrombotic events despite routine thromboprophylaxis. Understanding the complex mechanisms behind COVID-19-induced pulmonary thrombosis will lead to future combination therapies for hospitalized patients with severe disease that would target the crossroads of inflammatory and coagulation pathways.

Urgent and unexpected findings in oncology and hematology patients: A practical approach to imaging

Urgent and unexpected findings are very common in oncology and haematology patients. This article reviews the most important points included in the European Society of Radiology's guidelines and proposes a practical approach to reporting and communicating these findings more efficiently. This approach is explained with illustrative examples. Radiologists can provide added value in the management of these findings by helping referring clinicians reach the best decisions. To this end, it is essential to know the imaging manifestations of the most common findings that must be reported urgently, such as the specific toxicity of different treatments, the complications of tumours and catheters, infections, and thrombosis. Moreover, it is crucial to consider the individual patient's treatment, risk factors, clinical situation, and immune status.

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.

Long-term risk of recurrent venous thromboembolism among patients receiving extended oral anticoagulant therapy for first unprovoked venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

The long-term risk for recurrent venous thromboembolism (VTE) during extended anticoagulation for a first unprovoked VTE is uncertain.

OBJECTIVES

To determine the incidence of recurrent VTE during extended anticoagulation of up to 5 years in patients with a first unprovoked VTE.

METHODS

MEDLINE, EMBASE, and the Cochrane CENTRAL were searched to identify randomized trials and prospective cohort studies reporting recurrent VTE among patients with a first unprovoked VTE who were to receive anticoagulation for a minimum of six additional months after completing ≥3 months of initial treatment. Unpublished data on number of recurrent VTE and person-years, obtained from authors of included studies, were used to calculate study-level incidence rate, and random-effects meta-analysis was used to pool results.

RESULTS

Twenty-six studies and 15 603 patients were included in the analysis. During 11 631 person-years of follow-up, the incidence of recurrent VTE and fatal pulmonary embolism per 100 person-years was 1.41 (95% CI, 1.03-1.84) and 0.09 (0.04-0.16), with 5-year cumulative incidences of 7.1% (3.0%-13.2%) and 1.2% (0.4%-4.6%), respectively. The incidence of recurrent VTE was 1.08 (95% CI, 0.77-1.44) with direct oral anticoagulants and 1.55 (1.01-2.20) with vitamin K antagonists. The case-fatality rate of recurrent VTE was 4.9% (95% CI, 2.2%-8.7%).

CONCLUSIONS

In patients with a first unprovoked VTE, the long-term risk of recurrent VTE during extended anticoagulation is low but not negligible. Thus, clinicians and patients should be aware of this risk and take appropriate and timely action in case of suspicion of recurrent VTE. Estimates from this study can be used to advise patients on what to expect while receiving extended anticoagulation, and estimate the net clinical benefit of extended treatment to guide long-term management of unprovoked VTE.

Venous thromboembolism

Venous thromboembolism, comprising both deep vein thrombosis and pulmonary embolism, is a chronic illness that affects nearly 10 million people every year worldwide. Strong provoking risk factors for venous thromboembolism include major surgery and active cancer, but most events are unprovoked. Diagnosis requires a sequential work-up that combines assessment of clinical pretest probability for venous thromboembolism using a clinical score (eg, Wells score), D-dimer testing, and imaging. Venous thromboembolism can be considered excluded in patients with both a non-high clinical pretest probability and normal D-dimer concentrations. When required, ultrasonography should be done for a suspected deep vein thrombosis and CT or ventilation-perfusion scintigraphy for a suspected pulmonary embolism. Direct oral anticoagulants (DOACs) are the first-line treatment for almost all patients with venous thromboembolism (including those with cancer). After completing 3-6 months of initial treatment, anticoagulation can be discontinued in patients with venous thromboembolism provoked by a major transient risk factor. Patients whose long-term risk of recurrent venous thromboembolism outweighs the long-term risk of major bleeding, such as those with active cancer or men with unprovoked venous thromboembolism, should receive indefinite anticoagulant treatment. Pharmacological venous thromboembolism prophylaxis is generally warranted in patients undergoing major orthopaedic or cancer surgery. Ongoing research is focused on improving diagnostic strategies for suspected deep vein thrombosis, comparing different DOACs, developing safer anticoagulants, and further individualising approaches for the prevention and management of venous thromboembolism.

Urgent and unexpected findings in oncology and hematology patients: a practical approach to imaging

Urgent and unexpected findings are very common in oncology and hematology patients. This article reviews the most important points included in the European Society of Radiology's guidelines and proposes a practical approach to reporting and communicating these findings more efficiently. This approach is explained with illustrative examples. Radiologists can provide added value in the management of these findings by helping referring clinicians reach the best decisions. To this end, it is essential to know the imaging manifestations of the most common findings that must be reported urgently, such as the specific toxicity of different treatments, the complications of tumors and catheters, infections, and thrombosis. Moreover, it is crucial to consider the individual patient's treatment, risk factors, clinical situation, and immune status.

Biological Mediator-Propelled Nanosweeper for Nonpharmaceutical Thrombus Therapy

Traditional thrombolytic drugs offer limited outcomes due to short circulation half-life and low utilization. Herein, we have designed and constructed a biological mediator-propelled nanosweeper for highly efficient nonpharmaceutical thrombolysis and prevention of thrombus recurrence. Under the near-infrared light irradiation, the nanosweepers were activated to trigger nitric oxide (NO) release, which propelled the nanosweepers to penetrate deeply into the thrombus and resulted in enhanced site-pecific mechanical and photothermal thrombolysis. The experimental evidence confirmed that the ingenious nanosweeper displayed excellent site-specific thrombolytic efficacy even when compared with the clinical thrombolytic drug. In the meantime, as a biological mediator, the release of NO could effectively prevent thrombus recurrence in vivo. Overall, we anticipated that the nanosweeper would provide a promising strategy for the treatment of thrombi.

Anticoagulant therapy management of venous thromboembolism recurrence occurring during anticoagulant therapy: a descriptive study

Limited evidence exists regarding management of recurrent venous thromboembolism (VTE) that occurs during anticoagulant therapy. We aimed to describe patient characteristics, drug therapy management, and outcomes of patients with VTE recurrence during anticoagulant therapy. We identified 30 relevant episodes of VTE recurrence. Mean age was 48.9 (15.9) years, 56.7% were male, and 93.3% were White. Common VTE risk factors included cancer (46.6%), recent surgery (33.3%), and prolonged immobility (30.0%). At the time of recurrent VTE, 40.0% were receiving enoxaparin, 30.0% warfarin, and 23.3% direct oral anticoagulants. Potential causes for VTE recurrence included indwelling venous catheters (40.0%), cancer (33.3%), subtherapeutic anticoagulation (26.7%), and nonadherence (23.3%). Recurrent VTE management strategies included switching anticoagulants (26.7%), increasing anticoagulant dose (20.0%), temporarily adding enoxaparin or unfractionated heparin to oral anticoagulation therapy (13.3%), or no change in anticoagulation therapy (43.3%). Only four adverse 90-day outcomes occurred among 17 patients who received anticoagulant therapy changes in response to VTE recurrence, whereas eight adverse outcomes occurred in the 13 patients who received no change in anticoagulation therapy in response to a recurrent VTE episode (P value 0.04). Regardless of the potential etiology of recurrent VTE during anticoagulant therapy; switching anticoagulants, temporarily adding injectable anticoagulants, or increasing anticoagulant intensity appears preferable to continuing current anticoagulant therapy unchanged.