Presentation Details
| Unfractionated Heparin Use in the Setting of Acute Pulmonary Embolism David Scott1, Zhongyuan Chen1, Aniko Szabo1, Lindsay Hammons1, Lisa Baumann Kreuziger1, 2. 1Medical College of Wisconsin, Milwaukee, WI, USA.2Versiti Blood Center, Milwaukee, WI |
Abstract
Background: Unfractionated Heparin (UFH) is a frequent treatment for acute Pulmonary Embolism (PE) in the United States due to the ability to stop therapy if adverse effects occur or procedural intervention is required. UFH is known for having pharmacokinetics with poor predictability, which can make it difficult to dose appropriately, and can result in variable time to therapeutic dosing. This suboptimal timeframe in addition to narrow therapeutic range can lead to unpredictable time to therapeutic anti-coagulation which could influence patient outcomes. Methods: In a retrospective chart review of 346 patients who had activation of a Pulmonary Embolism Response Team for an acute PE from 2018 – 2021, we collected patient risk factors for PE, details regarding intervention for PE, and subsequent outcomes. Risk factors included time to therapeutic anticoagulation, supratherapeutic and subtherapeutic heparin levels, as well as PESI score. Outcomes were overall survival, and bleeding, and recurrent thrombosis. We used cox models to study potential predictors regarding clinical outcomes. Results: Average time to therapeutic anti-coagulation using UFH in the setting of acute PE was 18.9 hours (as measured by anti- Xa assay >0.3).76 patients did not reach therapeutic UFH levels for >24 hours. Patients taking >24 hours to reach a therapeutic UFH level had a correlation with overall mortality (p=0.124). A weaker correlation was found at 30-day mortality ( p=0.332) and 90-day mortality (p=0.739). This was found to be independent on whether the patient was subtherapeutic or supratherapeutic before becoming therapeutic (Fig 1). Patients who were subtherapeutic or supratherapeutic before being therapeutic were found not to have a significant increased mortality, PESI score was found to be significantly associated with overall mortality with patients having a high PESI score had a significantly higher risk for overall mortality (p= 7.01e-10) than those with low PESI scores (Figure 1).PESI and supratherapeutic anticoagulation was not found to be associated with risk of intracranial hemorrhage. Using cox model analysis, we found that only PESI score was an accurate predictor of overall, cardiac-related, PE-related and pulmonary-related mortality, and that sub-therapeutic or supratherapeutic status before therapeutic status did not have a significant impact on this metric. Conclusion: UFH does not reach therapeutic anticoagulation for 18 hours on average. Not reaching therapeutic anticoagulation within 24 hours was associated with an increase in morality. High PESI scores were associated with mortality and represent a high-risk group to target interventions.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.