From the Guidelines
Prophylactic anticoagulation in nephrotic syndrome should be started when the risk of thromboembolism exceeds the estimated patient-specific risks of an anticoagulation-induced serious bleeding event, with low molecular weight heparin (LMWH) or warfarin being the preferred anticoagulants. The decision to start prophylactic anticoagulation should be based on individual patient risk factors, including serum albumin levels, proteinuria, and history of thromboembolic events 1.
Key Considerations:
- Serum albumin levels: a level below 2.0-2.5 g/dL is considered high-risk for thrombosis, especially in patients with membranous nephropathy 1.
- Proteinuria: high levels of proteinuria increase the risk of thrombosis 1.
- History of thromboembolic events: patients with a history of thrombosis are at higher risk for future events 1.
Recommended Regimen:
- LMWH: enoxaparin 40 mg subcutaneously once daily or dalteparin 5000 units subcutaneously once daily 1.
- Warfarin: target INR 2-3, with monitoring of renal function and adjustment of dosing as needed 1.
Additional Considerations:
- For patients with severe renal impairment, unfractionated heparin may be preferred 1.
- In pregnancy, LMWH is safe and recommended 1.
- For long-term anticoagulation, transition to warfarin with target INR 2-3 may be considered 1. The most recent and highest quality study, published in 2023, supports the use of LMWH or warfarin for prophylactic anticoagulation in nephrotic syndrome, with careful consideration of individual patient risk factors and monitoring of renal function and bleeding risk 1.
From the Research
Timing of Prophylactic Anticoagulation
- The optimal timing for starting prophylactic anticoagulation in nephrotic syndrome is not clearly defined, but it is recommended to start as soon as possible after diagnosis, especially in patients with high risk of thromboembolic events 2, 3.
- Patients with severe hypoalbuminemia (serum albumin < 2.0 g/dl) may benefit from early initiation of prophylactic anticoagulation 4.
Choice of Anticoagulants
- Direct oral anticoagulants (DOACs) such as apixaban and rivaroxaban are effective and safe for prophylactic anticoagulation in patients with nephrotic syndrome 5, 6.
- Warfarin is also an option, but it may be associated with a higher risk of bleeding compared to DOACs 6.
- Low-dose prophylactic anticoagulation with low-molecular-weight heparin or low-dose warfarin may be considered in patients with serum albumin < 2.0 g/dl 4.
- Aspirin may be used as an alternative in patients with mild hypoalbuminemia (albumin levels 2.0-3.0 g/dl) 4.
Risk Factors and Considerations
- The severity of proteinuria and degree of hypoalbuminemia are common predictors of risk for thromboembolic events in patients with nephrotic syndrome 2, 3.
- Patients with membranous nephropathy may be at higher risk of thromboembolic events and may benefit from early initiation of prophylactic anticoagulation 3, 4.
- The risk of bleeding should be carefully considered when initiating prophylactic anticoagulation, and the choice of anticoagulant should be individualized based on patient-specific factors 3, 6.