"HALTing Progress: Unmasking Hypoattenuated Leaflet Thickening Post-Tra" by Lark Steafo, Parvathy Sankar et al.
 

HALTing Progress: Unmasking Hypoattenuated Leaflet Thickening Post-Transcatheter Aortic Valve Replacement (TAVR)

Document Type

Conference Proceeding

Publication Date

5-2025

Publication Title

American Journal of Respiratory and Critical Care Medicine

Abstract

Hypoattenuated leaflet thickening (HALT) is a recognized phenomenon occurring in patients who have undergone transcatheter aortic valve replacement (TAVR). HALT involves thrombus or fibrin accumulation on valve leaflets, which can restrict leaflet motion and potentially impair valve function and longevity. As TAVR use expands to include a broader range of patients—from high-risk to even low-risk populations—understanding the implications of HALT has become increasingly essential. HALT is typically identified through advanced imaging, such as four-dimensional computed tomography (4D-CT) or transesophageal echocardiography (TEE), as many affected patients remain asymptomatic. However, untreated HALT may raise the risk of adverse events, including stroke, valve thrombosis, and valve failure. Our case involves a 66-year-old female with a history of aortic sclerosis, post-TAVR with a 25 mm Inspiris valve placed in 2020, and COPD, who presented with a one-day history of shortness of breath. On examination, she was hypoxic with an oxygen saturation of 88% on room air and had diffuse crackles on lung auscultation. Laboratory tests revealed a BNP of 926 pg/mL. Chest x-ray was notable for diffuse bilateral interstitial opacities. Transthoracic and transesophageal echocardiography showed a left ventricular ejection fraction of 15%, grade II diastolic dysfunction, and low-flow, low-gradient severe aortic stenosis with restricted aortic leaflet motion. A left and right heart catheterization were performed showing only mild disease in the right coronary artery (RCA) and left anterior descending (LAD) artery and elevated right sided filling pressures, respectively. A dobutamine stress echo confirmed true severe aortic stenosis with minimal contractile reserve and no increase in the transvalvular gradient or stroke volume. She was subsequently placed on BiPAP and started on IV Lasix. Given these findings, consultations with both structural interventional cardiology and cardiothoracic surgery were conducted to assess her candidacy for surgical intervention. A CT TAVR protocol demonstrated significant hypoattenuated leaflet thickening. Following a multidisciplinary heart valve meeting, the team decided to anticoagulate the patient for three months with rivaroxaban to improve trans-aortic valve hemodynamics. Anticoagulation reduces the thrombotic burden on valve leaflets, improving valve hemodynamics by expanding the effective orifice area and decreasing transvalvular gradients. However, this case warrants further discussion for two key reasons. First, it highlights the value of a multidisciplinary approach—leveraging expertise from interventional cardiology, cardiac imaging, and cardiothoracic surgery—in managing HALT effectively. Second, it emphasizes the need for optimal surveillance strategies and anticoagulation therapy to mitigate HALT’s long-term impact on patient outcomes and valve function.

Volume

211

First Page

A1681

Comments

American Thoracic Society (ATS) International Conference, May 16-21, 2025, San Francisco, CA

Last Page

A1681

DOI

10.1164/ajrccm.2025.211.Abstracts.A1681

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