Abstract
BACKGROUND: Transcatheter heart valve (THV) deformation after transcatheter aortic valve implantation (TAVI) using the self-expanding ACURATE platform has been associated with impaired clinical outcomes in a randomised trial. Procedural factors associated with THV deformation remain incompletely understood. AIMS: We aimed to investigate procedural factors associated with valve underexpansion, mainly derived from preprocedural computed tomography angiography (CTA) imaging. METHODS: A single-centre, retrospective, observational study was carried out, including patients who underwent TAVI with an ACURATE THV between January 2014 and December 2022, with available CTA and procedural fluoroscopy. Aortic calcium volume was quantified using 3mensio software. Fluoroscopy was used to determine valve frame underexpansion. RESULTS: Of 3,027 patients, 480 were eligible (74 [15.4%] with an underexpanded and 406 [84.6%] with an expanded ACURATE THV). There were no differences regarding baseline clinical and procedural characteristics. Preprocedural CTA assessment showed more calcium at the annulus level in underexpanded versus expanded THVs (60.3 [interquartile range [IQR] 21.3; 135.2] mm(3) vs 45.3 [IQR 15.8; 96.1] mm(3), respectively; p=0.042), while post-dilatation was less frequently performed in underexpanded compared to expanded THVs (44.6% vs 64.8%, respectively; p=0.001). Multivariable regression analysis revealed that annulus calcium volume (odds ratio [OR] 2.333, 95% confidence interval [CI]: 1.331-4.089; p=0.003) and post-dilatation (OR 0.350, 95% CI: 0.203-0.602; p<0.001) were significantly associated with underexpanded THVs. Sensitivity analysis using annulus calcium volume as a dichotomised variable (>54 mm(3)) confirmed the significant association with valve frame underexpansion (OR 2.38, 95% CI: 1.37-4.19; p=0.002). CONCLUSIONS: Annular calcium volume was shown to be associated with underexpanded ACURATE THVs, while post-dilatation may reduce valve deformation.