What is the relationship between Nephrotic syndrome and Deep Vein Thrombosis (DVT)?

From the Guidelines

Nephrotic syndrome significantly increases the risk of deep vein thrombosis (DVT) due to urinary loss of anticoagulant proteins and increased production of procoagulant factors, and patients with nephrotic syndrome should receive prophylactic anticoagulation when the risk of thromboembolism exceeds the estimated patient-specific risks of an anticoagulation-induced serious bleeding event. The recommended approach for managing the risk of DVT in patients with nephrotic syndrome involves assessing the individual's risk factors, such as serum albumin level, proteinuria, and body mass index, as outlined in the 2021 KDIGO clinical practice guideline for the management of glomerular diseases 1. According to this guideline, prophylactic full-dose anticoagulation should be considered in patients with nephrotic syndrome when serum albumin is less than 20-25g/l and other risk factors are present, such as proteinuria greater than 10g/d or body mass index greater than 35 kg/m². The choice of anticoagulant should be based on the patient's specific risk factors and the potential for bleeding, with low molecular weight heparin (LMWH) or warfarin being preferred agents for treatment or prevention in those felt to have thromboembolic risk greater than bleeding risk 1. Key considerations in the management of DVT in patients with nephrotic syndrome include:

• Regular monitoring of renal function, albumin levels, and coagulation parameters
• Education of patients about DVT symptoms, including leg pain, swelling, and warmth, and the importance of seeking immediate medical attention if these develop
• Assessment of the individual's risk factors for thromboembolism and bleeding, using tools such as the online bleed risk calculator (www.med.unc.edu/gntools/bleedrisk.html) 1. It is also important to note that factor Xa inhibitors and direct thrombin inhibitors have significant albumin binding and are lost in nephrotic urine, and their pharmacokinetics are not well studied, making them not recommended at this time for patients with nephrotic syndrome 1. Overall, the management of DVT in patients with nephrotic syndrome requires a careful assessment of the individual's risk factors and a tailored approach to anticoagulation, with regular monitoring and education being key components of care.

From the Research

Relationship between Nephrotic Syndrome and Deep Vein Thrombosis (DVT)

• Nephrotic syndrome (NS) is associated with an increased risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) 2, 3, 4.
• The risk of thromboembolic events in NS patients varies with the nature of the underlying disease and seems to be greatest for membranous nephropathy 3.
• Other factors, including the level of serum albumin, previous thromboembolic episodes, and a genetically determined predisposition to thrombosis, may also contribute to the increased risk of DVT in NS patients 3.

Prophylactic Anticoagulation in NS Patients

• Prophylactic anticoagulation is recommended in NS patients with high risk of thromboembolic events, but the optimal type of anticoagulation is unknown 3, 4.
• Direct oral anticoagulants (DOACs) have been shown to be effective and safe in preventing VTE in NS patients, with a lower risk of non-major bleeding compared to warfarin 2, 5, 6.
• The use of DOACs, such as apixaban and rivaroxaban, has been studied in NS patients, and the results suggest that they may be a suitable option for prophylactic anticoagulation in this population 2, 5, 6.

Incidence of DVT and Bleeding Events in NS Patients

• The incidence of DVT in NS patients receiving prophylactic anticoagulation is estimated to be around 0.9% 4.
• The incidence of major bleeding in NS patients receiving prophylactic anticoagulation is estimated to be around 2.3% 4.
• The risk of bleeding events in NS patients receiving DOACs is generally considered to be low, with most studies reporting no major bleeding events or only minor bleeding episodes 2, 5, 6.