From the Guidelines
Aspirin can be used for 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, low-dose aspirin (81-325 mg daily) provides modest protection against venous thromboembolism, particularly in patients with an unprovoked proximal DVT or PE who are stopping anticoagulant therapy and do not have a contraindication to aspirin 1.
Key Considerations
- Aspirin works by inhibiting platelet aggregation through irreversible inhibition of cyclooxygenase-1, which reduces thromboxane A2 production.
- This antiplatelet effect is less potent for preventing venous clots than arterial thrombosis.
- For most high-risk patients, pharmacological prophylaxis with low molecular weight heparin (such as enoxaparin 40 mg subcutaneously daily), unfractionated heparin (5000 units subcutaneously two or three times daily), or direct oral anticoagulants (like rivaroxaban 10 mg daily) is preferred due to superior efficacy.
- Patients should be monitored for gastrointestinal side effects and bleeding complications.
Clinical Scenarios
- In patients with an unprovoked proximal DVT or PE who are stopping anticoagulant therapy and do not have a contraindication to aspirin, aspirin is suggested over no aspirin to prevent recurrent VTE (weak recommendation, low-certainty evidence) 1.
- Aspirin may be considered in people who are at substantially increased VTE risk and in whom LMWH or graduated compression stockings is not feasible (conditional recommendation, very low certainty in the evidence of effects) 1.
Important Notes
- Aspirin is not a reasonable alternative to anticoagulant therapy in patients who want extended therapy, as it is much less effective at preventing recurrent VTE than anticoagulants 1.
- The use of aspirin should be reevaluated when patients stop anticoagulant therapy because aspirin may have been stopped when anticoagulants were started 1.
From the Research
Aspirin for DVT Prophylaxis
- Aspirin has been debated as a potential option for the primary or secondary prophylaxis of venous thromboembolism (VTE), including deep vein thrombosis (DVT) 2.
- A study comparing aspirin and compression devices to low-molecular-weight heparin (LMWH) and pneumatic compression devices found no significant difference in DVT rate between the two groups in orthopedic oncology patients 3.
- A systematic review and meta-analysis of randomized clinical trials found that the incidence of VTE with aspirin was not significantly different from other anticoagulants in patients undergoing major orthopedic surgeries 4.
- The study also found no significant differences between aspirin and other anticoagulants in terms of mortality, bleeding events, or wound complications 4.
- Another study investigated the use of LMWH for VTE prevention in patients with intracerebral hemorrhage, but did not examine the use of aspirin for DVT prophylaxis 5.
- A study on the prevention of deep-vein thrombosis after total hip and knee replacement found that combined prophylaxis with LMWH and intermittent pneumatic compression was more effective than LMWH used with graduated compression stockings, but did not consider aspirin as an option 6.