Management of therapeutic unfractionated heparin in COVID‐19 patients: A retrospective cohort study

BACKGROUND: Patients hospitalized with severe acute respiratory syndrome coronavirus 2 infection are at risk for thrombotic complications necessitating use of therapeutic unfractionated heparin (UFH). Full‐dose anticoagulation limits requirements for organ support interventions in moderately ill patients with coronavirus disease 2019 (COVID‐19). Given this benefit, it is important to evaluate response to therapeutic anticoagulation in this population. OBJECTIVES: The aim of this study was to assess therapeutic UFH infusions and associated bleeding risk in patients with COVID‐19. PATIENTS/METHODS: This retrospective cohort study includes patients at Brigham and Women’s Hospital, Boston, Massachusetts, receiving weight‐based nursing‐nomogram titrated UFH infusion during a 10‐week surge in COVID‐19 hospitalizations. Of 358 patients on therapeutic UFH during this interval, 97 (27.1%) had confirmed COVID‐19. Patient characteristics, laboratory values, and information regarding UFH infusion and bleeding events were obtained from the electronic medical record. RESULTS: Patients who were COVID‐19 positive had fewer therapeutic activatrd partial thromboplastin times (aPTTs) compared to COVID‐19–negative patients (median rate, 40.0% vs 53.1%; P < .0005). Both major and clinically relevant nonmajor bleeding were increased in COVID‐19–positive patients, with major bleeding observed in 10.3% (95% confidence interval [CI], 5.7%‐17.9%) of patients who were COVID‐19 positive and 3.1% (95% CI, 1.6%‐5.9%) of patients who were COVID‐19 negative (P < .005). In logistic regression, bleeding events were associated with receiving UFH for longer than 7 days, but not platelet count, coagulation, or inflammatory measurements. CONCLUSIONS: Our data indicate a higher incidence of bleeding complications in patients with COVID‐19 receiving weight‐based nursing‐nomogram titrated UFH infusions despite a higher prevalence of subtherapeutic aPTTs in this population. These data underscore the need for prospective studies aimed at improving the quality and safety of therapeutic anticoagulation in patients with COVID‐19.