Abstract 3106: Location, and Not Simply Volume of Extra-valvular Calcification has Significant Impact on Aortic Stenosis Severity: Aortic Valve Area by Multislice Computed Tomography
Although calcification volume (CV) of the aortic valve (AV) leaflet correlates with aortic stenosis (AS) severity, the impact of calcium location within and outside the valve leaflets on stenosis severity is unknown. This study examined the relationship between leaflet and extra-valvular CV, and AS severity using multislice computed tomography (MSCT) in autopsy hearts.
Methods: Twenty post mortem human hearts with AS were scanned using MSCT. CVs were calculated for valves alone and for the entire hearts by commercial workstation. CV location was divided into seven in 3D: aortic root, cusps, left ventricular extension, mitral annulus, coronary artery, others, and entire heart. AV areas were planimetered by imaging the valves during valvuloplasty balloon inflation distended to physiologic pressure.
Results: Volume rendered images indicated extra-valvular CV markedly restricts hinge point cusp motion (Figure⇓). Univariate regression analysis showed statistically significant correlations among AV area and CV within the aortic root, cusps, and for the entire heart. Stepwise multiple regression analysis revealed that whole-heart CV was the single and most potent predictor of stenotic AV area (R2=0.444, p=0.0025).
CV is critical to determining aortic stenosis severity and calcium within the entire heart, rather than leaflets alone, best predicts stenotic AV area.
Aortic root CV that restricts leaflet hinge point motion has significant impact on stenosis severity.
These findings suggest that AS may relate to global CV factors affecting the entire heart and extra-valvular lesions, and may have implications for percutaneous AV procedures.