508 Incidence and determinants of prosthesis-patient mismatch after transcatheter aortic valve replacement using predicted indexed effective orifice area

Aims A small effective orifice area (EOA) by body surface area (BSA), defined as prosthesis–patient mismatch (PPM), is associated with elevated transprosthetic pressure gradients, less ventricular remodelling, and a worse prognosis. Calculating PPM by dividing the normal reference value of EOA for the model and size of the prosthetic valve (predicted PPM), instead of using the continuity equation has been recently confirmed as more accurate after trans catheter aortic valve intervention (TAVI), providing a stronger association with post-procedural haemodynamic outcomes. However, current evidence using this new definition is still limited, thus impairing generalizability. Accordingly, this analysis aims to extend such evidence providing incidence, and determinants of predicted PPM (PPMp) in an all-comers population undergoing TAVR with a high prevalence of self-expandable devices. Methods 395 patients who underwent TAVI at our Institution from September 2008 to November 2020 were included in this analysis. PPMp was then classified as moderate if ≤ 0.85 cm2/m2 and severe if ≤ 0.65 cm2/m2 as well as moderate if ≤ 0.70 cm2/m2 and severe if ≤ 0.55 cm2/m2 for patients with a body mass index > 30, as recommended by the Valve Academic Research Consortium-3 definition. The independent association between baseline clinical and procedural variables and the presence of moderate or severe PPMp was investigated with cross-sectional logistic regression analysis. Results 11 patients (2.78%) had severe and 33 (8.35%) moderate PPMp. Patients with moderate or severe PPMp (m/s PPMp) were younger, female, with a higher prevalence of hypercholesterolaemia, prior aortic valve implantation and balloon expandable device and lower prevalence of chronic obstructive disease (COPD). Post-procedural mean gradient was higher in patients with m/s PPMp. The independent clinical and procedural correlates associated with higher likelihood of m/s PPMp were valve in valve procedure (ViV) and the use of a balloon-expandable device. Conclusions Moderate or severe PPMp was observed only in a small part of patients underwent TAVI, leading, however, a higher post-procedural mean gradient compared to those without PPMp. Balloon expandable devices and ViV were the strongest determinant of moderate or severe PPM.