Incidental venous thromboembolism, detected by chance, but still venous thromboembolism

Cancer-Associated Venous Thromboembolism-Diagnostic and Therapeutic Considerations: An Update Based on the Revised AWMF S2k Guideline

Patients with cancer are prone to develop venous thromboembolism (VTE) with negative impact on quality of life, morbidity, and mortality. Treatment of established VTE is often complex in patients with cancer. Treatment of cancer-associated VTE (CAT) basically comprises initial and maintenance treatment, for 3 to 6 months, secondary preventions, and treatment in special situations. Therapeutic anticoagulation is the treatment of choice in CAT. In addition to the efficacy and safety of low-molecular-weight heparin (LMWH) that had been recommended for decades, direct oral anti-factor Xa inhibitors, a subgroup of direct oral anticoagulants (DOACs), demonstrated their advantages along with the accompanying concerns in several randomized controlled treatment trials of CAT. The latest guidelines, such as the German AWMF-S2k Guideline "Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism," agree with each other on most aspects with respect to the treatment of CAT. Encompassing recent clinical studies, and meta-analyses, as well as the focus on some special management aspects of CAT, the objective of this review is to present a current overview and recommendations for the treatment of CAT.

Prevalence and Risk Factors of Venous Thromboembolism in Critically Ill Patients with Severe COVID-19 and the Association between the Dose of Anticoagulants and Outcomes

Introduction

COVID-19 is characterized by a procoagulant state that increases the risk of venous and arterial thrombosis. The dose of anticoagulants in patients with severe COVID-19 pneumonia without suspected or confirmed thrombosis has been debated.

Aim of the study

We evaluated the prevalence, predictors, and outcomes of venous thromboembolism (VTE) in critically ill COVID-19 patients and assessed the association between the dose of anticoagulants and outcomes.

Materials and methods

This retrospective cohort included patients with COVID-19 who were admitted to the ICU between March and July 2020. Patients with clinically suspected and confirmed VTE were compared to those not diagnosed to have VTE.

Results

The study enrolled 310 consecutive patients with severe COVID-19 pneumonia: age 60.0±15.1 years, 67.1% required mechanical ventilation and 44.7% vasopressors. Most (97.1%) patients received anticoagulants during ICU stay: prophylactic unfractionated heparin (N=106), standard-dose enoxaparin (N=104) and intermediate-dose enoxaparin (N=57). Limb Doppler ultrasound was performed for 49 (15.8%) patients and chest computed tomographic angiography for 62 (20%). VTE was diagnosed in 41 (13.2%) patients; 20 patients had deep vein thrombosis and 23 had acute pulmonary embolism. Patients with VTE had significantly higher D-dimer on ICU admission. On multivariable Cox regression analysis, intermediate-dose enoxaparin versus standard-dose unfractionated heparin or enoxaparin was associated with lower VTE risk (hazard ratio, 0.06; 95% confidence interval, 0.01-0.74) and lower risk of the composite outcome of VTE or hospital mortality (hazard ratio, 0.42; 95% confidence interval, 0.23-0.78; p=0.006). Major bleeding was not different between the intermediate- and prophylactic-dose heparin groups.

Conclusions

In our study, clinically suspected and confirmed VTE was diagnosed in 13.2% of critically ill patients with COVID-19. Intermediate-dose enoxaparin versus standard-dose unfractionated heparin or enoxaparin was associated with decreased risk of VTE or hospital mortality.

Update: Antikoagulationstherapie bei tumorassoziierter venöser Thromboembolie

Bei Tumorpatienten sind symptomatische und sogenannte inzidentelle tiefe Venenthrombosen und Lungenembolien häufig. Es wird eine prolongierte, regelhaft über 3 Monate hinausgehende Antikoagulation empfohlen, wobei die therapiebedingte Zunahme eines bei Malignompatienten vorbestehend erhöhten Blutungsrisikos besonderer Berücksichtigung bedarf. Zusätzlich zu der bisher empfohlenen parenteralen Gabe niedermolekularer Heparine von Tumorpatienten stehen nun auch orale Faktor-Xa-Inhibitoren mit hohem Evidenzniveau gleichwertig für die Initialtherapie und Sekundärprophylaxe zur Verfügung. Die individuelle Entscheidung über Art, Dauer und Intensität der Antikoagulation sollte neben den tumorentitätsspezifischen Risiken für Blutungen und Rezidivthrombosen auch präparatespezifische Charakteristika, Therapiekosten und die Patientenpräferenz einbeziehen.

Rivaroxaban vs Dalteparin in Cancer-Associated Thromboembolism: A Randomized Trial

BACKGROUND

Direct oral anticoagulants (DOACs) are an alternative to low-molecular-weight heparin for treating cancer-associated VTE.

RESEARCH QUESTION

Is rivaroxaban as efficient and safe as dalteparin to treat patients with cancer-associated VTE?

STUDY DESIGN AND METHODS

In a randomized open-label noninferiority trial, patients with active cancer who had proximal DVT, pulmonary embolism (PE), or both were assigned randomly to therapeutic doses of rivaroxaban or dalteparin for 3 months. The primary outcome was the cumulative incidence of recurrent VTE, a composite of symptomatic or incidental DVT or PE, and worsening of pulmonary vascular or venous obstruction at 3 months.

RESULTS

Of 158 randomized patients, 74 and 84 patients were assigned to receive rivaroxaban and dalteparin, respectively. Mean age was 69.4 years, and 115 patients (76.2%) had metastatic disease. The primary outcome occurred in 4 and 6 patients in the rivaroxaban and dalteparin groups, respectively (both the intention-to-treat and per-protocol populations: cumulative incidence, 6.4% vs 10.1%; subdistribution hazard ratio [SHR], 0.75; 95% CI, 0.21-2.66). Major bleeding occurred in 1 and 3 patients in the rivaroxaban and dalteparin groups, respectively (cumulative incidence, 1.4% vs 3.7%; SHR, 0.36; 95% CI, 0.04-3.43). Major or clinically relevant nonmajor bleeding occurred in 9 and 8 patients in the rivaroxaban and dalteparin groups, respectively (cumulative incidence, 12.2% vs 9.8%; SHR, 1.27; 95% CI, 0.49-3.26). Overall, 19 patients (25.7%) and 20 patients (23.8%) died in the rivaroxaban and dalteparin groups, respectively (hazard ratio, 1.05; 95% CI, 0.56-1.97).

INTERPRETATION

In this trial comparing rivaroxaban and dalteparin in the treatment of cancer-associated VTE, the number of patients was insufficient to reach the predefined criteria for noninferiority, but efficacy and safety results were consistent with those previously reported with DOACs. An updated meta-analysis of randomized trials comparing DOACs with low-molecular-weight heparin in patients with cancer-associated VTE is provided.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT02746185; URL: www.clinicaltrials.gov.

Management of Cancer-Associated Thrombosis: Unmet Needs and Future Perspectives

Patients with cancer are at a high risk of symptomatic venous thromboembolism (VTE), which is a common cause of morbidity and mortality in this patient population. Increased risk of recurrent VTE and bleeding complications are two major challenges associated with therapeutic anticoagulation in these patients. Long-term therapy with low-molecular-weight heparins (LMWHs) has been the standard of care for the treatment of cancer-associated VTE given its favorable risk–benefit ratio in comparison with vitamin K antagonists. Direct oral anticoagulants (DOACs), which offer the convenience of oral administration and have a rapid onset of action, have recently emerged as a new treatment option for patients with cancer-associated thrombosis (CT). Randomized clinical trial data with head-to-head comparisons between DOACs and LMWHs showed that overall, DOACs have a similar efficacy profile but a higher risk of bleeding was observed in some of these studies. This review aims to identify unmet needs in the treatment of CT. We discuss important considerations for clinicians tailoring anticoagulation (1) drug–drug interactions, (2) risk of bleeding (e.g., gastrointestinal bleeding), (3) thrombocytopenia, hematological malignancies, (4) metastatic or primary brain tumors, and (5) renal impairment. Additional research is warranted in several clinical scenarios to help clinicians on the best therapeutic approach.