Some of the Ortho Trauma surgeons have begin to use Aspirin as a VTE prophylaxis.  I wanted to provide you the data in case you are questioning their orders.  The below information has been shared with their nurse practitioners that round on the 5MST patients (Amy and Luann). 

Based on the most recent trial with Xarelto and Aspirin, the patients should receive anticoagulant (not aspirin) for the first 5 days.  After 5 days of Xarelto (possibly Lovenox, Arixtra, etc), aspirin 81 mg DAILY could be given for additional 9 days post total knee, 30 days of aspirin post total hip.  Please note the exclusion criteria below when deciding if this is correct for the patient you are verifying orders. 

The ortho-trauma surgeons should be called if you feel the orders are inappropriate, as per routine.

Let me know if you have questions. 

Thanks, Jerry

Jerry Robinson, Pharm.D., BCPS
Clinical Specialist STICU/Co-Chairperson, Medication Safety Committee

The trial information and ACCP information is listed below.

NEJM article: February 22, 2018

Anderson DR, Dunbar M, Murnaghan J, et al. Aspirin or Rivaroxaban for VTE Prophylaxis After Hip or Knee Arthroplasty. N Engl J Med 2018;378:699-707.

Methods:  rivaroxaban 10 mg daily until post op day 5, then continued rivaroxaban or started aspirin 81 mg daily for additional 9 days after total knee, 30 days for total hip arthroplasty. 

Exclusion criteria:

• Hip or lower limb fracture in the previous 3 months
• Metastatic cancer
• Life expectancy <6 months
• History of major bleeding
• History of aspirin allergy, active peptic ulcer disease, or gastritis
• History of significant hepatic disease or any other condition that in the judgment of the investigator precludes the use of rivaroxaban
• Creatinine clearance <30 ml/min
• Platelet count <100 x 109 /L
• Need for long-term anticoagulation due to a pre-existing comorbid condition or due to the development of venous thromboembolism (VTE) following surgery, but prior to randomization
• Did not or will not receive rivaroxaban postoperatively for VTE prophylaxis
• Bilateral total hip arthroplasty or simultaneous hip and knee arthroplasty
• Major surgical procedure within the previous 3 months
• Requirement for major surgery post-arthroplasty within 90-day period
• Chronic daily aspirin use with dose >100 mg a day

Results: 3424 patients (1804 hip, 1620 knee) ; VTE event rate 11 aspirin pt (0.64%) vs 12 rivaroxaban (0.7 %). Major bleeding 8 aspirin pt vs 5 rivaroxaban. Clinically important bleeding  in 22 aspirin group versus 17 in rivaroxaban group.

Authors conclusion: aspirin was not significantly different from rivaroxaban in prevention of vte.

From ACC - The results of this important trial indicate that extended-duration treatment with low-dose aspirin is noninferior to low-dose rivaroxaban for thromboprophylaxis among patients undergoing total knee or hip replacement. Overall rates of symptomatic VTE were very low with both strategies; bleeding rates were also similar. Of note, all patients received rivaroxaban 10 mg for 5 days postoperatively. Given the cost differences between the two drugs, this trial has the potential to significantly influence clinical practice and guidelines. In the EPCAT I trial, extended-duration aspirin was noninferior to short-duration low molecular weight heparin (LMWH) for surgical thromboprophylaxis. Interestingly, in the RECORD trials (1-4), rivaroxaban 10 mg was found to be superior to LMWH for the same indication. The trial populations may be somewhat different, and it is unclear if patients at highest risk for VTE events would benefit from rivaroxaban compared with aspirin.

A trend toward higher bleeding rates among the patients who continued long-term aspirin therapy in addition to trial-assigned aspirin serves as a reminder that, whenever possible, we should use daily aspirin doses of <100 mg.