Transcatheter Aortic Valve Oversizing: A Comparison of Leaflet Stress and Strain Distribution

Background: The purpose of this study was to measure volume and distribution of aortic valve calcium using multislice computed tomography (MSCT) and to define whether they predict paravalvular regurgitation (PAR) after transcatheter aortic valve replacement (TAVR). Methods: A total of 263 patients underwent TAVR between August 2008 and September 2013. The MSCT scans were analyzed for the volume and distribution of calcium. Leaflet calcium volume and asymmetry index ((maximum leaflet calcium volume – minimum leaflet calcium volume)/sum of maximum and minimum leaflet calcium volume) were scored. Correlation between aortic valve calcium volume and asymmetry index with post-procedural PAR on discharge transthoracic echocardiography was investigated. Results: Fourty-six percent of patients had no or trivial PAR (grade less than 1), 46% had mild PAR and 8% moderate to severe. The volume of annular calcium was higher in patients with mild or moderate to severe PAR compared to patients with PAR grade less than 1 (2023.1 916.4 ml, 2270.8 1558.3 ml and 1700,9 976.9 ml respectively, p1⁄40.024). No association was found between aortic valve calcium asymmetry and PAR severity. Multivariate analysis, including aortic valve calcium volume, asymmetry index of calcium distribution, and other factors that might be associated with PAR (among others aortic annulus area and valve prosthesis type) showed aortic valve calcium volume as the only independent predictor of PAR severity (B1⁄40.00034, p1⁄40.019). Conclusions: Increasing volume of aortic valve calcium predicts the severity of PAR after TAVR. Asymmetrical distribution of calcium in the aortic valve apparatus is not correlated with the severity of PAR after TAVR.