Influence of Left Ventricular Geometry and Body-surface Area on Mitral Annulus Dimensions – Assessment by Computed Tomografy

• Published in: RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren
• Main Authors: Blanke, P, Berger, A, Bilbey, N, Gao, M, Grewal, J, Boone, R, Webb, J, Pache, G, Leipsic, J
• Format: Conference Proceeding
• Language: English
• Published: 21.04.2015
• ISSN: 1438-9029; 1438-9010
• DOI: 10.1055/s-0035-1550961

Zielsetzung: 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 CT and to investigate their predictors. Material und Methodik: CT data sets of 136 patients (mean age 58.3 ± 11.2 years) 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-to-trigone (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. Ergebnisse: Mean mitral annular area was 9.1 ± 1.6cm2. Mean TT- distance and the mean SL-distance were 27.8 ± 3.2 mm and 28.3 ± 3.0 mm. The mean 2D projected perimeter of the PML insertion was 82.3 ± 8.0 mm. 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). Schlussfolgerungen: 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.