Pre-op anticoagulation reduces VTE risk in cancer patients

Anna GarrettVenous thromboembolism (VTE) is a frequent cause of morbidity during cancer treatment, and although a number of studies have found that postoperative anticoagulation decreases rates of VTE in surgical oncology patients, the effect of adding preoperative anticoagulation to postoperative VTE prophylaxis is largely unknown.

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Now researchers at Memorial Sloan Kettering Cancer Center in New York have found that rates of deep venous thrombosis and pulmonary embolism were significantly lower among patients who received preoperative chemoprophylaxis than in those who did not.

Investigators selected 2,058 patients who were undergoing major cancer surgery to receive preoperative VTE prophylaxis of either low-molecular-weight heparin (LMWH) (40 mg enoxaparin) or unfractionated heparin (5,000 units). Anticoagulation was administered in the preoperative holding area by the nursing staff within two hours of surgery.

Bleeding, transfusion, and VTE rates were compared with those of 4,960 historical controls who did not receive preoperative VTE chemoprophylaxis.

Patients who received the intervention did not have a statistically significant difference in the rate of major bleeding events. They also had lower rates of both documented bleeding and blood transfusion, as well as statistically significant lower rates of documented DVT and pulmonary embolism. 

Source: Selby LV, Sovel M, Sjoberg DD, et al. Preoperative chemoprophylaxis is safe in major oncology operations and effective at preventing venous thromboembolism. J Am Coll Surg. 2015. Published online December 14, 2015. http://www.journalacs.org/article/S1072-7515(15)01712-3/abstract.

Heart failure raises VTE risk: Meta-analysis

Among hospitalized patients, heart failure appears to be an independent risk factor for VTE, according to a recently published meta-analysis.The analysis included 71 studies reporting absolute or relative risks for VTE among hospitalized heart failure patients. Overall, the VTE rate was 1.5% among heart failure patients who received thromboprophylaxis and 3.7% for those who did not. The rate was highest among patients with both heart failure and cancer (6.6%). After multivariable adjustment, heart failure was associated with a 50% increased risk for VTE.

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The authors concluded that heart failure is an independent risk factor for VTE and that thromboprophylaxis should be considered in clinical practice for high-risk patients.

Source: Tang L, Wu Y, Lip GYH, et al. Heart failure and risk of venous thromboembolism: A systematic review and meta-analysis. Lancet Haematology. Published online December 3, 2015. http://www.thelancet.com/journals/lanhae/article/PIIS2352-3026(15)00228-8/abstract.

Switch to warfarin from LMWH safe in cancer patients

Switching to warfarin after six months of anticoagulant treatment with LMWH appears to be safe in patients with cancer-associated thrombosis.

LMWH is considered to be the treatment of choice for anticoagulation therapy for cancer-associated thrombosis, with treatment for at least three to six months after diagnosis. However, the data regarding LMWH treatment beyond six months are unclear.  

Researchers compared the two options in a retrospective registry study. The cohort included 1,502 patients who were enrolled in the RIETE Registry and who had already completed six months' treatment with a LMWH. About half of the patients continued receiving LMWH (n=763); for the other half, therapy was changed to warfarin (n=739).

The primary outcome was time to recurrence of VTE. The secondary outcome was major bleeding, defined as bleeding associated with a decrease in hemoglobin of 20 g/L or more requiring at least 2 units of red blood cell transfusion, bleeding into a critical organ, fatal bleeding, or nonmajor bleeding.

There were no significant differences in the two groups with regard to recurrent VTE or major or nonmajor bleeding. Results suggest that switching to warfarin after initial treatment with LMWH is safe.

Source: Chai-Adisaksopha C, Iorio A, Crowther MA.Switching to warfarin after 6-month completion of anticoagulant treatment for cancer-associated thrombosis.American Society of Hematology (ASH) 57th Annual Meeting. Abstract 430. Presented December 7, 2015. https://ash.confex.com/ash/2015/webprogram/Paper81374.html