The calcific aortic stenosis (AS) is characterized by progressive obstruction of the aortic valve opening and results from the action of several active cellular processes that lead to valve remodelling, promote fibrosis and valvular calcification. The purpose of the study is to assess the relationship between the severity of aortic valve calcifications quantified by the Agatston score density and the hemodynamic impact of aortic stenosis determined through Doppler echocardiography. The authors performed a retrospective analysis of 70 cases that benefited of transcatheter aortic valve implantation between January 2015-October 2019. All patients underwent cardiac computed tomography and comprehensive Doppler echocardiography prior to the procedure. The degree of calcification of aortic leaflets was quantified on non-contrast CT examinations in all cases using the Agatston score and its relationship with dynamic echocardiographic parameters was evaluated using specific statistical tests. Aortic valve Agatston score density showed a significant correlation with mean transvalvular gradient (R = 0,62, p<0.0001) same as age (R = 0.51, p = 0.036). These parameters together with sex, body mass index, body surface area, the status of arterial hypertension, dyslipidaemia, smoking, bicuspid aortic valve, history of coronary artery disease were introduced into a multivariate regression to identify independent predictors of the mean transvalvular gradient. Age (ß= -0.25, p = 0.003), aortic valve Agatston score density (ß =-0.63, p<0.001) and bicuspid aortic valve (ß = -0.32, p = 0,003) proved to be the only independent predictors of the haemodynamic severity of aortic stenosis. In conclusion, the degree of aortic valve calcifications is a strong indicator for the haemodynamic impact of AS. Cardiac computed tomography is a non-invasive and accurate method of evaluating aortic valve calcifications and could be used to grade the severity of AS in cases where echocardiographic findings are discordant.
Keywords: transcatheter aortic valve implantation, leaflet calcification, hydroxyapatite, Agatston score, transvalvular gradient