From the Guidelines
A patient with a Geneva score of 7, indicating moderate to high risk of pulmonary embolism (PE), should be prescribed enoxaparin despite being on aspirin, as aspirin alone is insufficient for PE treatment or prevention. The European Society of Cardiology guidelines recommend anticoagulation with low molecular weight heparin (LMWH) such as enoxaparin for patients with non-high-risk PE, which includes those with a moderate to high Geneva score 1. Aspirin only inhibits platelet aggregation, whereas full anticoagulation is necessary to prevent clot extension and allow for clot dissolution.
Key considerations for initiating enoxaparin include:
- Dosing: typically 1 mg/kg twice daily or 1.5 mg/kg once daily
- Initiation: should be prompt, while awaiting confirmatory testing such as CT pulmonary angiography
- Continuation of aspirin: does not need to be discontinued unless there are specific bleeding concerns
- Therapeutic goal: achieve adequate anticoagulation to prevent clot propagation and reduce mortality risk
- Duration of anticoagulation: typically at least 3 months if PE is confirmed, with consideration for transition to oral anticoagulants like direct oral anticoagulants (DOACs) or warfarin after initial stabilization
- Monitoring: patients should be monitored for bleeding complications, especially if maintained on both medications, as recommended by guidelines 1.
From the Research
Patient Assessment with Geneva Score
- The Geneva score is used to assess the clinical probability of pulmonary embolism (PE) in patients, with scores ranging from 0 to 12 points 2.
- A score of 7 indicates a moderate to high risk of PE.
- The simplified Geneva score has been prospectively validated and can be used to determine pretest probability, with a score of 7 falling into the intermediate to high clinical probability category 2.
Anticoagulation Therapy for PE
- The standard treatment for PE typically involves anticoagulation with unfractionated heparin or low molecular weight heparin (LMWH), such as enoxaparin 3, 4.
- Enoxaparin has been shown to be effective as monotherapy for the treatment of symptomatic PE, with a lower risk of major bleeding complications compared to unfractionated heparin 4.
- The use of enoxaparin as VTE prophylaxis in ICU patients has been compared to unfractionated heparin, with similar prevalence of DVT and PE, but a higher mortality rate associated with unfractionated heparin 5.
Aspirin and Enoxaparin Therapy
- There is no direct evidence to suggest that aspirin therapy alone is sufficient for the treatment of PE, especially in patients with a moderate to high risk of PE 3, 4, 6, 5, 2.
- Given the patient's Geneva score of 7, indicating a moderate to high risk of PE, and the fact that they are already on aspirin, it is likely that enoxaparin would still be necessary to provide adequate anticoagulation and prevent further thromboembolic events 3, 4.