Abstract 4141292: Neo-Sinus Washout Time Following Transcatheter Aortic Valve Replacement and Hemodynamic Outcomes

Background: Leaflet thrombosis and associated transcatheter heart valve (THV) dysfunction are major concerns in managing transcatheter aortic valve replacement (TAVR) recipients. Prolonged neo-sinus contrast washout time (NWT) may increase the risk of hypoattenuated leaflet thickening (HALT) and leaflet thrombosis, leading to early valve degeneration. This study aims to assess the association between NWT measured in-vivo and hemodynamic outcomes in patients undergoing TAVR. Methods: In this retrospective cohort study, NWT was obtained from aortograms using computer vision algorithm in 2256 patients (mean [SD] age 79 [9] years; 40% female) who underwent TAVR at our center between 2016 and 2020. NWT was stratified into terciles (T1: <1.33 s, T2: 1.33-2.08 s, T3: >2.08 s) and adjusted for heart rate (HR). Hemodynamic assessments focused on transvalvular aortic mean and peak gradients post-TAVR, with evaluations at 30-day and 1-year follow-ups. The association between NWT and HALT presence was also studied. Unpaired t test was used to compare the gradients between terciles at different time points. Mann-Whitney test was used to compare NWT between HALT and no HALT. Results: At the 30-day follow-up, the transvalvular aortic mean gradient was higher in T3 compared to T1 (12.61 [5.07] mm Hg vs. 11.98 [4.75] mm Hg, p=0.03). At the 1-year follow-up, patients with 29 mm valves in T3 had higher mean gradients than those in T1 (11.13 [4.35] mm Hg vs. 9.65 [3.85] mm Hg, p=0.04). Patients with 30-day HALT exhibited significantly greater NWT (z=-2.06, p=0.04). Conclusion: Prolonged NWT measured in-vivo is associated with elevated transvalvular aortic mean gradients at both 30-day and 1-year follow-ups post-TAVR. Moreover, patients with HALT had higher NWT. NWT can help identify patients at risk of valve deterioration and HALT at an early stage, guiding post-procedural pharmacotherapy.