Tinzaparin Lead-In to Prevent the Post-Thrombotic Syndrome

The TILE pilot study will be a multicenter, open-label, assessor-blinded RCT (randomized control trial) comparing extended LMWH (Low Molecular Weight Heparin) vs. DOAC (Direct Oral Anticoagulants) to PTS (prevent post thrombotic syndrome) in patients with DVT (Deep Vein Thrombosis).

The TILE pilot study will investigate the magnitude of difference in effectiveness between LMWH (low molecular weight heparin, tinzaparin) plus DOAC (Direct Oral Anticoagulants, rivaroxaban) vs. DOAC alone to determine the sample size and assess feasibility for a larger study assessing the effectiveness of an initial 3-week lead-in course of LMWH (tinzaparin) compared to DOAC alone (rivaroxaban) in patients with proximal DVT (Deep Vein Thrombosis) at high risk of developing PTS (Post-Thrombotic Syndrome). PTS is a frequent, costly and burdensome complication of DVT, especially for patients with iliac or femoral vein DVT who have a high risk of developing PTS and severe PTS. Anticoagulant therapy appears to influence this risk, with a higher frequency of PTS in patients with DVT who receive suboptimal treatment with a VKA (Vitamin K Antagonist). DOAC are expected to avoid this and other limitations of VKA therapy and have become the standard of care for patients with DVT. Extended treatment of DVT with LMWH, by providing more effective anticoagulation and by reducing inflammation, appears to restore venous patency and reduce venous reflux compared to VKA and probably to DOAC. Extended treatment of DVT with LMWH, therefore, has the potential to reduce PTS.

Eligibility Criteria:
Inclusion Criteria:

1. Patients with objectively confirmed acute (i.e. onset of symptoms \<10 days) symptomatic iliac or common femoral DVT (DVT diagnosis will be made with a Compression Ultrasound (CUS) according to standardized consensus criteria)

Exclusion Criteria:

1. Age \< 18 years
2. History of ipsilateral DVT (distal and/or proximal)
3. Active cancer
4. Thrombolysis or other invasive early thrombus removal technique to treat DVT or PE
5. Pregnant or breast feeding
6. Impaired renal function (creatinine clearance \< 30 ml/min according to Cockcroft-Gault formula)
7. Concomitant use of drugs that interact with rivaroxaban (i.e. keto- or itraconazole, ritonavir)
8. Allergy or hypersensitivity to heparin or rivaroxaban, including heparin induced thrombocytopenia
9. Anticoagulant therapy contraindicated because of presence of active bleeding or condition with high risk of bleeding (e.g. peptic ulcer, acute or subacute septic endocarditis, uncontrolled severe hypertension, other)
10. Thrombocytopenia (platelet count \< 100 x 109/L)
11. Liver disease (including Child-Pugh Class B and Class C) associated with coagulopathy
12. Body weight \> 120 kg or \< 40 kg
13. Need for treatment with daily NSAIDs or antiplatelet agent (ibuprofen \< 1200 mg/day, aspirin ≤ 160 mg/day or clopidogrel ≤ 75 mg/day are permitted)
14. Treatment with therapeutic doses of anticoagulants for \> 72 hours
15. Mechanical heart valve
16. Antiphospholipid syndrome
17. Sulphite sensitivity
18. Lactose sensitivity
19. Life expectancy \< 1 year
20. Unable or unwilling to provide informed consent