Can aspirin (acetylsalicylic acid) be used as Deep Vein Thrombosis (DVT) prophylaxis?

From the Guidelines

Aspirin can be used as DVT prophylaxis in certain clinical scenarios, but it is not the first-line option for most patients. According to the most recent and highest quality study, the American Society of Hematology 2020 guidelines for management of venous thromboembolism, aspirin may be considered for secondary prevention of VTE in patients who are going to discontinue anticoagulant therapy after completion of the primary treatment phase, but its use needs to be individualized 1.

Key Considerations

• Aspirin has shown modest efficacy in preventing venous thromboembolism, particularly following orthopedic procedures like total hip or knee replacement.
• For patients with higher thrombotic risk, such as those with active cancer, previous DVT, or multiple risk factors, more potent anticoagulants like low molecular weight heparin (enoxaparin 40 mg daily), direct oral anticoagulants (rivaroxaban 10 mg daily, apixaban 2.5 mg twice daily), or fondaparinux are preferred.
• Aspirin works by inhibiting platelet aggregation through irreversible inhibition of cyclooxygenase-1, which provides some protection against thrombosis but is less effective than agents that directly target the coagulation cascade.
• The use of aspirin for DVT prophylaxis should be continued for the duration of the high-risk period, typically 10-35 days following surgery, depending on the specific procedure and patient risk factors.

Evidence Summary

The most recent study from 2021, antithrombotic therapy for VTE disease: second update of the CHEST guideline and expert panel report, suggests that aspirin is not a recommended alternative to anticoagulation, based on direct and indirect comparisons demonstrating that the net benefit of extended anticoagulant therapy in patients with unprovoked VTE is substantially greater than the benefits of extended aspirin therapy 1. However, another study from 2021, executive summary: antithrombotic therapy for VTE disease: second update of the CHEST guideline and expert panel report, suggests that aspirin may be considered for patients who have decided to stop anticoagulants, as it provides some protection against recurrent VTE, although its benefits must be balanced against its risk of bleeding and inconvenience 1.

Clinical Decision Making

In clinical practice, the decision to use aspirin as DVT prophylaxis should be made on a case-by-case basis, taking into account the patient's individual risk factors, medical history, and potential contraindications to other anticoagulant agents. Aspirin may be considered as an alternative to more potent anticoagulants when the risk of bleeding is high or when patients have contraindications to other agents. However, for patients with higher thrombotic risk, more potent anticoagulants are generally preferred.

From the Research

Aspirin as DVT Prophylaxis

• Aspirin has been debated as a potential prophylaxis for deep vein thrombosis (DVT) due to its antiplatelet properties 2.
• A study published in 2024 found that low-dose aspirin is a safe and effective method of prophylaxis for patients undergoing total knee arthroplasty, regardless of their risk profile 3.
• The study compared the efficacy of aspirin with other chemoprophylactic agents and found that aspirin reduced the odds of DVT, pulmonary embolism, bleeding, infections, and hospitalizations 3.
• Another study published in 2015 found that aspirin, along with vitamin K antagonists (VKA) and direct oral anticoagulants (DOACs), significantly reduced the risk of recurrent venous thromboembolism (VTE) 4.
• However, the study also found that VKA and DOACs were more effective than aspirin in reducing the risk of recurrent VTE 4.
• The use of aspirin as DVT prophylaxis may be considered as an alternative to other anticoagulants, especially in patients who are at high risk of bleeding or have contraindications to other anticoagulants 2, 3, 4.

Comparison with Other Anticoagulants

• Fondaparinux, a synthetic pentasaccharide, has been found to be effective as an alternative anticoagulant to warfarin or low-molecular-weight heparin for recurrent venous thrombosis 5.
• A review of anticoagulants published in 2013 found that novel oral anticoagulants have emerged as a replacement for older agents due to their ease of use and more favorable pharmacodynamic profiles 6.
• However, the main concerning adverse event with all anticoagulants, including aspirin, is hemorrhage 6.