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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
| Adequacy of Standard Therapeutic Low–Molecular-Weight Heparin Dosing in Pregnant Women with Prosthetic Heart Valves: An Anti-Factor Xa–Based Evaluation (THSNA �Travel Awardee) Tushar Sehgal1, K.Aparna Sharma2, Ambuj Roy3. 1Department of Laboratory Medicine, Delhi, India.2Department of Obstetrics and Gynaecology, Delhi, India.3Department of Cardiology, Delhi, India |
Abstract
Background: Therapeutic anticoagulation during pregnancy in women with prosthetic heart valves or other cardiac indications is challenging due to pregnancy-related physiological changes that may alter low–molecular-weight heparin (LMWH) pharmacokinetics. Anti-factor Xa monitoring is recommended, but real-world adequacy of standard weight-based LMWH dosing remains uncertain. Objectives: To evaluate whether standard therapeutic LMWH dosing (enoxaparin 1 mg/kg twice daily) achieves target anti-factor Xa levels in pregnant women with prosthetic valves or other high-risk cardiac indications. Methods: A total of 21 pregnant women receiving therapeutic LMWH for prosthetic valve replacement or other cardiac indications were included. Anti-factor Xa activity was measured and categorized as therapeutic (0.5–1.2 IU/mL), sub-therapeutic (<0.5 IU/mL), or supratherapeutic (>1.2 IU/mL). Results were analyzed overall and stratified by valve type or indication. Results: The median age was 28 years (range: 22–47 years). The overall mean anti-factor Xa level was 0.36 IU/mL (median 0.27; range 0.01–1.07 IU/mL). Only 7 patients (33.3%) achieved therapeutic anti-factor Xa levels, while 14 patients (66.7%) remained sub-therapeutic. No patient demonstrated supratherapeutic activity. Among mitral valve replacement (MVR) patients (n=9), only 3 (33.3%) reached therapeutic levels, with the lowest median anti-Xa activity (0.16 IU/mL). Therapeutic levels were achieved in 40% of aortic valve replacement (AVR) patients, 33.3% of double valve replacement (DVR) patients, and 50% of PTMC patients, while all patients with other indications (TGA and MCA infarction) remained sub-therapeutic. Conclusion: The majority of pregnant women receiving standard weight-based therapeutic LMWH fail to achieve target anti-factor Xa levels, with MVR patients particularly vulnerable to under-anticoagulation. These findings underscore the need for individualized, anti-Xa–guided LMWH dosing strategies in pregnancy, rather than reliance on standard dosing regimens, to minimize the risk of valve thrombosis and other thromboembolic complications.
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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.