Management of Heparin-Induced Thrombocytopenia in Dialysis Patients
For dialysis patients with acute HIT requiring anticoagulation during dialysis, use argatroban, danaparoid, or bivalirudin as first-line alternatives to heparin. 1, 2, 3
Acute HIT During Dialysis
First-Line Anticoagulant Selection
The American Society of Hematology recommends three specific non-heparin anticoagulants for acute HIT patients requiring dialysis circuit anticoagulation: 1
Argatroban is the preferred choice due to its lack of renal clearance, making it ideal for dialysis patients where drug accumulation is a concern 2, 3. Standard therapeutic doses can be used without adjustment, though close monitoring is recommended 2. Prospective studies demonstrate low rates of new thrombosis (0-4%) and major bleeding (0-6%) 3. The drug is not significantly removed by high-flux dialysis membranes 2, 3.
Danaparoid is an effective alternative despite dependence on renal clearance, with extensive clinical experience supporting its use 3. A retrospective review showed thrombosis of either the patient or dialysis circuit in only 7% of cases, with major bleeding in 6% 3.
Bivalirudin serves as a third option when argatroban or danaparoid are unavailable 1, 3. However, it requires dose reduction in severe renal impairment: 1.0 mg/kg/hour for CrCl <30 mL/min, and 0.25 mg/kg/hour for patients on hemodialysis 2.
Selection Factors
Your choice among these three agents should be guided by: 1, 2, 3
- Renal function: Argatroban is superior in renal failure due to hepatic metabolism 2, 3
- Liver function: Avoid argatroban in severe hepatic impairment 1
- Drug availability and cost: Argatroban may be prohibitively expensive at some centers 1, 3
- Monitoring capability: Ability to measure anticoagulant effect varies by agent 1, 3
- Institutional experience: Clinician familiarity influences safety 1, 2
Subacute, Remote, or Past HIT During Dialysis
For patients with subacute HIT (platelet count recovering but antibodies still present), remote HIT (>30 days but <3 months), or past HIT (>3 months ago) requiring dialysis, use regional citrate anticoagulation rather than heparin or non-heparin anticoagulants. 1, 2
Regional citrate provides similar efficacy with superior safety compared to heparin, including reduced bleeding and reduced HIT recurrence risk 1. It is familiar to clinicians, inexpensive compared to other alternatives, and provides regional rather than systemic anticoagulation 1, 2. The American College of Chest Physicians specifically recommends citrate over heparin or LMWH for patients with past HIT requiring ongoing renal replacement therapy 1.
Critical caveat: Citrate is not appropriate for patients with acute HIT who require systemic anticoagulation for thrombosis treatment, as it only provides regional anticoagulation 2.
Evidence Quality and Practical Considerations
The evidence supporting these recommendations is based on very low certainty data from nonrandomized studies, as no RCTs exist comparing these agents in HIT patients on dialysis 1. Among the 97 patients with HIT who received argatroban across multiple studies, 18 deaths occurred (none from thrombosis), with major bleeding in 5 patients and new thrombotic events in 3 patients 1. For danaparoid, among 115 HIT patients on hemodialysis, 8 developed nonfatal thromboembolic events (2 requiring amputation), 28 died, and 11 had nonfatal major bleeding 1.
Common Pitfalls to Avoid
- Never continue heparin or LMWH once HIT is suspected—discontinue immediately and start alternative anticoagulation before serologic confirmation 4, 5
- Do not use fondaparinux or rivaroxaban as first-line agents in dialysis patients with acute HIT due to renal clearance dependence and limited data 1
- Avoid lepirudin in dialysis patients due to prolonged half-life and accumulation risk between sessions 3, 6
- Do not delay treatment waiting for antibody test results—the moment HIT is suspected, switch anticoagulation 4
Alternative Strategies for High Bleeding Risk
If acute HIT occurs in a patient with active bleeding or high bleeding risk, consider: 7, 6
- Heparin-free dialysis with saline flushes if the prothrombotic state has resolved (platelet count normalized) 1
- Peritoneal dialysis as a temporary measure to avoid circuit anticoagulation entirely 7
- Nafamostat mesilate (where available) for regional anticoagulation in bleeding patients 7
These approaches are based on limited case series but represent reasonable options when systemic anticoagulation poses unacceptable bleeding risk 7, 6.