Rofo 2015; 187 - WS_WISS201_3
DOI: 10.1055/s-0035-1550961

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

P Blanke 1, A Berger 2, N Bilbey 2, M Gao 2, J Grewal 2, R Boone 2, J Webb 2, G Pache 3, J Leipsic 2
  • 1St. Paul's Hospital & University of British Columbia, Center for Heart Valve Innovation, Vancouver
  • 2St. Paul's Hospital & University of British Columbia, Center for Heart Valve Innovation, Vancouver
  • 3Radiologische Klinik – Universitaetsklinik Freiburg, Sektion fuer kardiovaskulaere Bildgebung, Freiburg/Bad Krozingen

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.