PB0511 - Safety and efficacy of therapeutic anticoagulation with subcutaneous unfractionated heparin in patients with renal failure

Background: Intravenous unfractionated heparin (UFH) infusion is the conventional approach in patients with renal failure requiring treatment dose anticoagulation. However, it requires intensive monitoring, often a challenge outside high dependency/intensive care units. A weight-adjusted, unmonitored subcutaneous UFH (SCUFH) regimen avoids these problems and has been successfully trialled but is not widely used.

Aims: To assess:
1.Safety and efficacy of therapeutic anticoagulation with SCUFH in patients with renal failure with or without requiring dialysis
2.Factors that may link to increase risk of bleeding

Methods: This is a single-centre retrospective cohort study of 45 patients with renal failure, who received treatment dose SCUFH (250 IU/kg) from September 2020 to August 2021 across three hospitals in North-West London. The cases were identified using an electronic pharmacy database. Demographics, co-morbidities, medications, indication for anticoagulation, duration of treatment, baseline platelet count, renal function, and fibrinogen levels were recorded. The study was approved by institutional review board.

Results: Median age was 76 (range 40-102) years. Male: Female ratio was 22/23. The majority needed anticoagulation for either treatment of venous thromboembolism (48.9%) or atrial fibrillation (37.8%), while the remaining six patients received SCUFH as bridging peri-operatively. The median time on SCUFH was 3 (1-65) days. Baseline clinical, laboratory characteristics and outcomes of the patients are summarised in table 1.

No breakthrough thrombosis was observed. Seven patients experienced clinically significant bleeding. Of these, 3 had major bleeding which was the cause of presumed death in 2 cases (Table 2). There was no difference in in age, sex, dialysis status, number of comorbidities, creatinine, platelet count, fibrinogen levels and days of exposure to SCUFH between patients experiencing bleeding versus no bleeding.

Conclusion(s): Weight-adjusted SCUFH is an effective anticoagulant regimen in preventing thrombosis. However, the rate of bleeding was relatively high in our cohort, with notably 3 major gastrointestinal bleeds.