Risk factors for thrombosis in cancer patients

Apixaban and dalteparin in active malignancy associated venous thromboembolism. The ADAM VTE Trial

Currently, low molecular weight heparin (LMWH) is the guideline endorsed treatment of patients with cancer associated venous thromboembolism (VTE). While apixaban is approved for the treatment of acute VTE, there are limited data supporting its use in cancer patients. The rationale and design of this investigator initiated Phase IV, multicenter, randomized, open label, superiority trial assessing the safety of apixaban versus dalteparin for cancer associated VTE is provided (ADAM-VTE; NCT02585713). The main aim of the ADAM-VTE trial is to test the hypothesis that apixaban is associated with a significantly lower rate of major bleeding compared to dalteparin in the treatment of cancer patients with acute VTE. The primary safety outcome is rate of major bleeding. Secondary efficacy objective is to assess the rates of recurrent VTE or arterial thromboembolism. Cancer patients with acute VTE (n=300) are randomized to receive apixaban (10 mg twice daily for 7 days followed by 5 mg twice daily thereafter) or dalteparin (200 IU/Kg daily for 30 days followed by 150 IU/kg daily thereafter) for 6 months. Stratification factors used for randomization include cancer stage and cancer specific risk of venous thromboembolism using the Khorana score. Participating centers are chosen from the Academic and Community Cancer Research United (ACCRU) consortium comprised of 90 oncology practices in the United States and Canada. Based on the hypothesis to be tested, we anticipate that these trial results will provide evidence supporting apixaban as an effective treatment of cancer associated VTE at lower rates of major bleeding compared to LMWH.

Periprocedural anticoagulant management

Approximately 6 million Americans are treated with chronic anticoagulation. Of these, 10% of patients will require temporary anticoagulation interruption for an invasive procedure each year. Anticoagulation management during this period requires a formal strategy in order to limit both bleeding and thromboembolic complications. This article will give health care providers a stepwise approach to this process. The first step is to determine whether warfarin discontinuation is necessary for the planned procedure. For procedures requiring warfarin discontinuation, the second step is to determine the appropriate timing. The third step is to identify the patient-specific thromboembolic risk in order to determine which patients require bridging therapy with parenteral anticoagulants. The fourth step is both the most complicated and most critical step in this management strategy. This decision-making step involves choosing the appropriate anticoagulant regimen, dose, and timing of reinitiation that is best tailored to a specific patient, as well as determining procedural variables, in order to limit bleeding and thrombotic complications.

Portal venous thrombosis after distal pancreatectomy: clinical outcomes

AIM

Outcomes of patients developing portal vein (PV) thrombosis (PVT) after distal pancreatectomy (DP) are unknown. The goal of this study was to identify risk factors for PVT and describe the long-term outcomes in these patients.

METHODS

Patients undergoing DP without repair or reconstruction of the PV between 2001 and 2011 were included. Patients that showed evidence of PVT on pre-operative imaging were excluded from the study. Location and extent of thrombosis was determined by post-operative computed tomography or ultrasound imaging in all patients. Evidence of systemic thrombosis (if present) in addition to PVT was also documented.

RESULTS

In the study period, 991 patients underwent DP and 21 (2.1%) patients were diagnosed with PVT. Pancreatic neoplasm was the most frequent indication for operation (n = 11). Thrombus occurred in the main PV in 15 and the right branch of the PV in 8 patients. Complete PV occlusion occurred in nine patients with a median time to diagnosis of 16 days (range 5-85 days). Seventeen patients were anticoagulated for a median duration of 6 months (range 3.3-36 months) after the diagnosis of PVT. Over a median follow-up of 22 months, resolution of PVT occurred in seven patients. Predictors of non-resolution of PVT included anesthesia time >180 min (p = 0.025), DM type II (p = 0.03), BMI >30 Kg/m(2) (p = 0.03), occlusive PVT (p < 0.001), or thrombus in a sectoral branch (p = 0.02). Anticoagulation therapy did not influence the frequency of thrombus resolution and was complicated by gastrointestinal hemorrhage in four patients. There was no mortality as a direct result of PVT or anticoagulation.

CONCLUSION

PVT after distal pancreatectomy is a rare complication. Serious complications as a direct result of PVT in this setting are uncommon and are not dependent on thrombus resolution. Although anticoagulation does not appear to influence the rate of PVT resolution in this small retrospective series, we support the use of anticoagulation until larger, controlled studies define clear advantages or disadvantages.

Cancer effect on periprocedural thromboembolism and bleeding in anticoagulated patients

BACKGROUND

Patients with active cancer are often on chronic anticoagulation and frequently require interruption of this treatment for invasive procedures. The impact of cancer on periprocedural thromboembolism (TE) and major bleeding is not known.

PATIENTS AND METHODS

Two thousand one hundred and eighty-two consecutive patients referred for periprocedural anticoagulation (2484 procedures) using a standardized protocol were followed forward in time to estimate the 3-month incidence of TE, major bleeding and survival stratified by anticoagulation indication. For each indication, we tested active cancer and bridging heparin therapy as potential predictors of TE and major bleeding.

RESULTS

Compared with patients without cancer, active cancer patients (n=493) had more venous thromboembolism (VTE) complications (1.2% versus 0.2%; P=0.001), major bleeding (3.4% versus 1.7%; P=0.02) and reduced survival (95% versus 99%; P<0.001). Among active cancer patients, only those chronically anticoagulated for VTE had higher rates of periprocedural VTE (2% versus 0.16%; P=0.002) and major bleeding (3.7% versus 0.6%; P<0.001). Bridging with heparin increased the rate of major bleeding in cancer patients (5% versus 1%; P=0.03) without impacting the VTE rate (0.7% versus 1.4%, P=0.50).

CONCLUSIONS

Cancer patients anticoagulated for VTE experience higher rates of periprocedural VTE and major bleeding. Periprocedural anticoagulation for these patients requires particular attention to reduce these complications.