Low-Dose Apixaban Added to Standard Heparin Lock Versus Heparin Lock Alone to Prevent Tunneled Hemodialysis Catheters Dysfunction (APICATH-HD)

Prior treatment

• Tunneled catheter placed \<8 days before randomization or radiographically confirmed catheter tip malposition at screening.
• Concomitant use of other systemic anticoagulants (e.g., warfarin, low-molecular-weight heparin, other DOACs) or high-intensity antiplatelet therapy (e.g., dual antiplatelet therapy).
• Women of childbearing potential who are unwilling to use a highly effective contraception method during the study and for 48 hours after the last dose of study medication.
• Life expectancy \<6 months, current palliative/hospice care, or planned kidney transplant within ≤3 months.
• Concurrent participation in another clinical trial that could interfere with the study interventions or outcomes.

Other illness

• High bleeding risk (HAS-BLED score \>3) or major bleeding that is active or recent.
• Known coagulopathy; history of heparin-induced thrombocytopenia (HIT); or allergy/hypersensitivity to heparin, citrate, or rt-PA (alteplase).
• Severe hepatic impairment (e.g., Child-Pugh class C), clinically significant liver dysfunction that contraindicates DOAC therapy, or ongoing hemodialysis with regional citrate anticoagulation that cannot be modified per protocol.
• Active catheter exit-site infection or bloodstream infection/bacteremia at the time of randomization.

Lab values

• Active bleeding; active peptic ulcer disease; or clinically significant gastrointestinal bleeding within the past 30 days; uncorrectable INR \>1.5; platelet count \<100,000/µL.

Other

• Non-tunneled hemodialysis catheter, subclavian catheter, or intracaval catheter placement not consistent with the protocol (e.g., catheter located in the SVC/IVC without a subcutaneous tunnel, or catheter location/site not permitted by the study).
• Pregnancy or breastfeeding.
• Venography demonstrating significant venous stenosis involving the superior vena cava (SVC) or inferior vena cava (IVC).

• Age ≥18 years with end-stage kidney disease (CKD stage 5) receiving maintenance hemodialysis or initiating hemodialysis.
• Recently placed tunneled, double-lumen central venous hemodialysis catheter (tunneled CVC) in place for ≥8 days, with a post-placement radiograph confirming adequate tip position.
• Permitted catheter insertion sites: right internal jugular, left internal jugular, right femoral, or left femoral vein.
• Adequate initial catheter function, defined as ability to achieve the prescribed extracorporeal blood flow (suggested ≥300 mL/min) for ≥8 days after catheter placement.
• Conventional in-center hemodialysis schedule (2-3 sessions/week) at the study unit, with expected ability to complete follow-up for up to 24 months.
• Written informed consent provided.
• Willingness to receive only the protocol-assigned antithrombotic prophylaxis and to avoid non-study systemic anticoagulants or antiplatelet agents during the study period.