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Thank you for attending THSNA 2026. The virtual meeting is now closed.
Thank you for attending THSNA 2026. The virtual meeting is now closed.
Presentation Details
| Evaluation of Updated Protocol for Intraoperative Antithrombin-III and Unfractionated Heparin Administration During Cardiac Surgery Razan Fannoun, Stephanie Davis, Katie Dane, John Lindsley, Margaret Buck, Jessica Crow, Promise Ariyo. The Johns Hopkins Hospital, Baltimore, MD, USA |
Abstract
Background: Cardiac surgery with cardiopulmonary bypass (CPB) necessitates systemic anticoagulation to prevent thrombosis in the extracorporeal circuit. Weight-based unfractionated heparin (UFH), typically 300-400 units/kg, is administered to achieve activated clotting times (ACT) above 400-480 seconds before CPB initiation. Heparin resistance, defined as failure to achieve target ACT despite standard UFH dosing, affects up to 20% of cardiac surgery patients. Contributing factors include antithrombin III (ATIII) deficiency, elevated fibrinogen, paraprotein, or heparin neutralization by platelet factor 4 and other heparin-binding proteins. Current blood conservation guidelines support ATIII concentrate administration for heparin resistance. Although ATIII administration improves heparin responsiveness, randomized controlled trials have failed to demonstrate improvements in clinical outcomes in adults, and a meta-analysis has raised concern for a potential signal of harm. Given the multifactorial nature of heparin resistance, high ATIII cost, and emerging safety concerns, a revised intraoperative anticoagulation protocol for CPB was implemented at a large academic medical center. Key changes included increasing initial UFH bolus, administration of two to three units of fresh frozen plasma (FFP) before ATIII consideration, and restricted ATIII use to cases with persistent ACT <480 seconds despite cumulative administration of UFH boluses of > 650 units/kg. Objectives: To determine whether the updated intraoperative anticoagulation protocol for CPB altered UFH dosing patterns, ATIII utilization, ACT response, and transfusion-related outcomes in patients undergoing CPB. Methods: This IRB-approved retrospective cohort study will include adults undergoing cardiac surgery with CPB between September 2022 and February 2023 (pre-implementation) and April 2023 and September 2023 (post-implementation). Data will be obtained from the Society of Thoracic Surgeons registry and electronic medical records. Primary outcomes include UFH dosing prior to CPB initiation, UFH dosing prior to FFP or ATIII administration, the number of ATIII administrations, and the proportion of cases requiring ATIII. Secondary outcomes include ACT at the time of CPB initiation, maximum ACT, time from UFH bolus to CPB, intraoperative blood loss, red blood cell transfusion, prothrombin complex concentrate use, and the frequency of ACT values exceeding the assay’s upper limit. Continuous variables will be analyzed using independent t-tests or Wilcoxon rank-sum tests, and categorical variables will be analyzed using chi-square testing. Results: Data retrieval and cohort construction will begin following completion of the approved data pull. Conclusions: This study will evaluate the clinical and stewardship impact of a revised anticoagulation strategy incorporating higher initial UFH dosing, FFP administration before ATIII, and conditional ATIII supplementation. Findings will help guide evidence-based, cost-conscious anticoagulation practices for CPB.
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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.