SLR - July 2023 - Gabriella Ley, DPM
Title: Aspirin or Low-Molecular-Weight Heparin for Thromboprophylaxis after a FractureReference: O'Toole RV, Stein DM, O'Hara NN, Frey KP, Taylor TJ, Scharfstein DO, Carlini AR, Sudini K, Degani Y, Slobogean GP, Haut ER, Obremskey W, Firoozabadi R, Bosse MJ, Goldhaber SZ, Marvel D, Castillo RC. Aspirin or Low-Molecular-Weight Heparin for Thromboprophylaxis after a Fracture. N Engl J Med. 2023 Jan 19;388(3):203-213
Level of Evidence: I
Scientific Literature Review:
Reviewed by: Gabriella Ley, DPM
Residency Program: Regions Hospital/Healthpartners Institute, St. Paul, MN
Podiatric Relevance: Thromboprophylaxis is an important practice in the field of podiatric medicine with regards to trauma due to the potentially fatal complication of venous thromboembolism (VTE). Nonfatal deep venous thrombosis and/or pulmonary embolism can also lead to complications such as chronic swelling to the lower extremity and/or need for long term anticoagulation which can be limiting and expensive. Low-dose aspirin is a relatively cheap and accessible over-the-counter medication which has been used in orthopedic surgery for deep venous thrombosis (DVT) prophylaxis in surgical and nonsurgical lower extremity trauma. Prophylactic subcutaneous low-molecular-weight-heparin (LMWH) is often used in the hospital setting for DVT prophylaxis in orthopedic patients which is more technically difficult to self-administer and can be costly. Adverse events such as increased bleeding risk is a major consideration with choice of thromboprophylaxis in patients with a lower extremity fracture who may undergo surgical intervention. This study aims to compare effectiveness of aspirin vs LMWH for thromboprophylaxis after a fracture in the extremities or pelvis or acetabulum.
Methods: This study was a randomized controlled trial where the Prevention of Clot in Orthopedic Trauma (PREVENT CLOT) trial compared the safety of thromboprophylaxis with aspirin vs LMWH in patients with a fracture. Patients ages 18 years and older with an extremity fracture treated operatively or fracture of the pelvis or acetabulum treated operatively or nonoperatively were included. Fractures of the lower extremity included the hip to the midfoot. Fractures of the forefoot including digits and metatarsals were excluded. Patients were randomly assigned 1:1 into 2 groups: subcutaneous enoxaparin of a dose of 30 mg twice daily vs aspirin 81 mg twice daily. Primary outcome was death from any cause at 90 days. Secondary outcomes included cause-specific death, nonfatal pulmonary embolism, DVT. Other secondary outcomes included bleeding events, wound complications, and surgical site infections.
Results: A total of 12, 211 patients were included in this randomized controlled trial which were evenly distributed into the aspirin and low molecular weight heparin group. At time of discharge, both groups were prescribed 21 days of thromboprophylaxis with 94.4% protocol-adherence in the aspirin group and 86.6% in the LMWH. With regards to the primary outcome, aspirin was found to be noninferior but not superior to LMWH in preventing death from any cause in patients with a pelvic, acetabular facture, or a fracture of the extremities treated operatively. Fewer DVTs were seen in the LMWH vs the aspirin group as well as fewer distal DVTs, comparatively.
Conclusion: The authors found that aspirin is as safe and effective as LMWH in preventing fatal thromboembolism after orthopedic trauma. There were lower incidences of DVTs and distal DVTs in the LMWH group compared to the aspirin group. Patient compliance with drug administration, cost, and increased bleeding risk are important considerations for patients who undergo surgery for trauma of the lower extremity. Although this trial was not specific to lower extremity trauma, this high level study further supports that aspirin is effective in preventing fatal thromboembolism in a patient population the podiatric surgeon will often encounter.