Periprocedural Thrombogenicity Change Is Associated With Subclinical Leaflet Thrombosis Progression in Patients Undergoing Transcatheter Aortic Valve Implantation.

Background: Subclinical leaflet thrombosis occasionally occurs after transcatheter aortic valve implantation (TAVI), but its exact etiology and relationship with thrombogenicity remain unknown. Methods and Results: This study enrolled 35 patients who underwent TAVI. Thrombogenicity was evaluated using a total thrombus-formation analysis system (T-TAS) to compute the thrombus-formation area under the curve (PL₁₈-AUC₁₀ and AR₁₀-AUC₃₀). Periprocedural thrombogenic parameters including T-TAS were investigated at pre-TAVI, 2 days, 7 days, and 3 months post-TAVI. Hypoattenuated leaflet thickening (HALT) and maximum leaflet thickness (MLT) were evaluated using contrast-enhanced computed tomography 7 days and 3 months post-TAVI. The associations between thrombogenicity and HALT or MLT were assessed. T-TAS parameters consistently decreased at 2 and 7 days post-TAVI, followed by improvement at 3 months. HALT was detected in 20% and 17% of patients at 7 days and 3 months, respectively, post-TAVI. The median MLT value was 1.60 mm at 7 days and 3 months post-TAVI. A significant positive correlation was observed between the decrease in the AR₁₀-AUC₃₀ and MLT at 7 days post-TAVI. Univariate linear regression analysis revealed a decrease in the AR₁₀-AUC₃₀ and an increase in the D-dimer level as a significant predictor of MLT deterioration. Conclusions: The findings suggested that a transient decrease in thrombogenicity following TAVI predicts leaflet thrombosis, implying that monitoring thrombogenicity may be useful for predicting progression of leaflet thrombosis.