A1262 JACC March 17, 2015 Volume 65, Issue 10S
Non Invasive Imaging (Echocardiography, Nuclear, PET, MR and CT) Influence of Left Ventricular Geometry and Body-Surface Area on Mitral Annulus Dimensions: Assessment by Computed Tomography Poster Contributions Poster Hall B1 Sunday, March 15, 2015, 3:45 p.m.-4:30 p.m. Session Title: Non Invasive Imaging: CT/Multimodality, Angiography, and Non-CT Angiography Abstract Category: 16. Non Invasive Imaging: CT/Multimodality, Angiography, and Non-CT Angiography Presentation Number: 1207-025 Authors: Philipp Blanke, Adam Berger, Nicolas Bilbey, Min Gao, Pascal Thériault Lauzier, Anson Cheung, Ye Jian, Chesnall Arepalli, Jasmine Grewal, Christopher Thompson, Robert Moss, Robert Boone, Nicolo Piazza, John Webb, Jonathan Leipsic, University of British Columbia -St. Paul’s Hospital, Vancouver, Canada
Background: Mitral annular dimensions assessed by CT constitute essential information for planning of transcatheter mitral valve implantation. Normative data is limited, and the influence of gender, body-surface area (BSA) and cardiac chamber dimensions is unknown. We sought to establish normative data on mitral annular dimensions by computed tomography and to investigate the influence of sex, bodsurface-area, left ventricular and atrial dimensions.
Methods: CT data sets of 136 patients (mean age 58.3±11.2 years, 75 male) without known mitral valve disease who had undergone retrospectively ECG-gated cardiac CT to rule out coronary artery disease were assessed for mitral annular dimensions, left ventricular end-diastolic volume (LVEDV) and end-systolic left atrial volume (LAV). In specific, mitral annular dimensions were obtained at end-diastole using semi-automated segmentation and comprised projected area, projected perimeter, septal-to-lateral (SL) distance and trigone-totrigone (TT) distance. Importantly, the mitral annulus was defined by the TT distance and the insertion of the posterior mitral leaflet (PML) thereby excluding the intervalvular fibrosa. Pearson correlation analysis and a step-wise multiple linear regression model were performed. Results: Mean mitral annular area was 9.1±1.6cm2. Mean TT distance and the mean SL distance were 27.8±3.2mm and 28.3±3.0mm. The mean 2D projected perimeter of the PML insertion was 82.3±8.0mm. Wide inter-subject variability was noted in all parameters which showed normal distribution. Annular area exhibited a significant (p<0.001) and positive correlation with BSA (r=0.60), LVA (r=0.57) and LVEDV (r=0.74). According to the multiple linear regression model, male gender (standardized β 0.19, p=0.004), higher BSA (β 0.43, p<0.01), higher left atrial volume (β 0.005, p=0.01) and higher end-diastolic volume (β 0.04, p=0.01) were independently associated with a larger mitral annular area (adjusted r2=0.65). Conclusion: Mitral annular dimensions determined by cardiac CT exhibit a wide inter-subject variability. Gender, BSA, left atrial and ventricular volume are independent predictors of mitral annular dimensions.