THromboprophylaxis In Sickle Cell Disease With Central Venous Catheters (THIS)

THromboprophylaxis In Sickle Cell Disease With Central Venous Catheters (THIS): A Pilot Study

Research Question:

In adult SCD patients with CVC, is it feasible and safe to conduct an adequately powered RCT to evaluate the use of rivaroxaban as thromboprophylaxis in this population?

Study Design:

The study is a vanguard pilot double blind multi-centre randomized controlled trial. Participants with SCD and CVC will be randomized to either rivaroxaban 10mg PO daily or placebo for the duration of CVC in situ or for up to one year, whichever is less. After screening (day -7 to day -1), patients will be followed at day 1, months 3 (+/- 15 days), 6 (+/- 15 days), 9 (+/- 15 days), and 12 (+/- 15 days).

Study Objectives:

The primary objective is to estimate the proportion of eligible patients who will enroll into a trial of thromboprophylaxis.

Secondary objectives include (a) document indications for central venous catheter (CVC), (b) summarize duration of CVC insertion prior to enrollment, (c) estimate adherence to the study drug, (d) estimate proportions of participants being compliant with study procedures, and lost to follow up.

Exploratory objectives will assess thrombotic, bleeding, and quality of life outcomes.

Inclusion Criteria:

1. Adult (age 18 or older)
2. Documented SCD
3. New or pre-existing CVC planned for long term use (at least 6 months)
4. Able to provide written consent

Exclusion Criteria:

1. Contra-indication to prophylactic dose anticoagulation or active bleeding at discretion of treating physician
2. Already on anticoagulation (prophylactic or therapeutic dose) for an indication other than CVC thromboprophylaxis
3. Previous VTE within the past 3 months
4. Pregnant, within 6 weeks post-partum, or active breast feeding
5. Creatinine clearance <30mL/min (as calculated by Cockcroft-Gault equation[67])
6. Acute hepatitis or chronic active hepatitis
7. Cirrhosis with Child-Pugh score B or C
8. Platelet count < 50 x109/L
9. Weight <40kg
10. Uncontrolled HTN (systolic blood pressure > 170mmhg, or diastolic blood pressure> 100mmhg) despite antihypertensive treatment
11. On palliative care
12. On dual antiplatelet therapy, or high dose single agent aspirin > 325mg/day
13. On combined P-glycoprotein and strong cytochrome P450 3A4 inhibitors (including but not limited to ketoconazole and protease inhibitors)
14. On combined P-glycoprotein and strong cytochrome P450 3A4 inducers (including but not limited to rifampin, phenytoin, phenobarbital, carbamazepine, and st. john's wort)
15. Active cancer or treatment for cancer excluding basal cell carcinoma
16. Known allergy to study drug
17. Strong indication for thromboprophylaxis at discretion of treating physician
18. Significant medical condition that confers an unacceptable risk to participating in the study, and/or that could confound the interpretation of the study data.