Anticoagulant stewardship: A modern review of unfractionated heparin treatment

Introduction: Recent guidelines advocate a preference for low molecular weight heparin (LMWH) over unfractionated heparin (UFH) infusions to reduce the risk of major bleeding (MB) and heparin-induced thrombocytopenia, as well as to improve cost-effectiveness. 1–6 Canadian initiatives have been successful in eliminating UFH administration in unnecessary situations. 7 In this study, we analyzed UFH use at a tertiary centre in Canada to identify cases in which UFH could have been avoided, identify characteristics associated with bleeding, and examine the efficacy and safety of infusions where the initial bolus was administered or withheld. Methods: We identified adults who received between 48 and 96 hours of a UFH infusion in a tertiary care hospital between 2021 and 2023. Consecutive patients were reviewed for bleeding events, patient factors known to influence bleeding, and whether patients had a contraindication to LMWH or another anticoagulant. Patients were deemed to have “appropriate” use of UFH in preference to more desirable anticoagulants if they had recent or ongoing bleeding, required an imminent procedure or surgery, have severe renal dysfunction (eGFR <30 mL/min), or could foreseeably require thrombolysis. Results: Of 127 patients, 16 (13%) were identified to have bleeding complications, including 14 episodes of MB. Bleeding episodes were significantly associated with any measured aPTT greater than 150 seconds (s) during treatment ( P = .0285). Omission of initial bolus dosing was not associated with reduced bleeding events or the incidence of any aPTT measurement >150s. Omission of initial bolus dosing was associated with subtherapeutic aPTT measurement at 6 hours (46%) and 12 hours (25%) post-UFH administration. We identified high rates (42%) of UFH selection where an alternative anticoagulant could have been used. Conclusion: We demonstrate a high rate of avoidable intravenous UFH selection at a tertiary Canadian centre. We observed high bleeding rates with UFH that were not mitigated by omitting the initial bolus. We suggest institutional policies to improve and restrict the use of UFH.