(427) Unfractionated Heparin: A Knee-Jerk Response for Initial Management of Pulmonary Embolism?

Introduction: There has been a paradigm shift in the choice of agents for anticoagulation for venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) from parenteral to direct oral anticoagulants (DOACs) with evidence to suggest low molecular weight heparin (LMWH) and DOACs to be non-inferior to unfractionated heparin (UFH) for initial anticoagulation. In 2010 the US Food and Drug Administration (FDA) approved several DOACs, which further became part of VTE treatment guidelines in 2016. UFH continues to be preferred over DOACs for initial anticoagulation for VTE.

Methods: We performed a retrospective chart review in patients admitted from 01/01/2017- 06/01/2022 with an admission diagnosis of VTE, including DVT, PE, or both. We aimed to compare the various initial anticoagulation choices, including UFH, LMWH, apixaban, and fondaparinux. The primary outcome was the proportion of patients with indications for procedure: evidence of right ventricular (RV) strain, extensive clot burden, hemodynamic instability, and hypoxemia with or without respiratory distress (RD). The secondary outcomes included mean length and cost of hospital stay.

Results: A total of 408 patients met the inclusion criteria. The mean patient age was 67, with a fairly equal distribution of males (49.7%) and females (50.2%). Caucasians were the majority of the patient population (84.8%). Of the admitted patients, 33.1% had a DVT, 44.1% had a PE, and 22.8% had both. For initial anticoagulation 50%, 37.9%, 10.3%, and 1.7% of the patients received UFH, LMWH, apixaban, and fondaparinux, respectively. Of the 142 patients diagnosed with PE started on UFH, 70% of them had at least one indication for possible intervention and only 20% underwent thrombolytic therapy. The mean length of stay for patients started on UFH was 8.08 days compared to 5.24 days for LMWH (p=0.0002) and 5 days for apixaban (p=0.01). The mean cost of stay was 71,540 USD for patients on UFH compared to 42,667 USD for LMWH (p=0.004) and 57,270 USD for apixaban (p=0.26).

Conclusions: Our results support the cost-effectiveness of LMWH and DOAC use over UFH in a community hospital and showed that nearly 1 in 3 patients with PE who did not meet the criteria for possible intervention were initiated on UFH.