POST-IMPLANT TRANSCATHETER AORTIC PROSTHESIS DEFORMATION: TRICUSPID VERSUS BICUSPID VALVE.

Objective: There is conflicting evidence supporting the widespread use of transcatheter aortic prostheses for bicuspid valves. In these patients, prosthesis deformation, also known as non- uniform expansion, may frequently occur. Little information is available regarding post- implant prosthesis behaviour in the context of native tricuspid versus bicuspid aortic valve stenosis, particularly following self-expandable valves. Methods: We analysed 100 consecutive post-implant multi detector computed tomography scans to assess prosthesis non-uniform expansion at six pre-specified valvular levels, and other specific parameters, including valvular and perivalvular thrombosis at six months follow-up. Echocardiographic prosthesis performance and clinical outcome was also evaluated. Results: Mean eccentricity was significantly higher in the bicuspid group (0.43 ± 0.09 vs 0.37± 0.08, p=0.005, bicuspid vs tricuspid); valvular and perivalvular thrombosis were also significantly more frequent in the bicuspid than in the tricuspid group (81% vs. 36.9%, p=0.031); there was no significant difference in terms of mean prosthetic gradient at follow-up between groups (7.31 ± 5.53 mmHg vs 7.09 ± 3.05 mmHg, p= 0.825); EOAi was also similar between bicuspid and tricuspid (1.08 ± 0.12 cm 2 vs 1.03 ± 0.13 cm 2 , p=0.101), with no significant changes compared to discharge. However, the bicuspid valve was associated with a significantly higher risk of adverse events (HR:3.72, 95%CI: 1.07-13.4, p= 0.027). Conclusions: Higher levels of eccentricity, which indicates prosthesis deformation, is often detected in bicuspid valves. Although echocardiographic performance was not affected, this might have led to an increased incidence of thrombosis at valvular and perivalvular levels and worse outcomes