Value of cardiac CT in comprehensive aortic valve and root evaluation before percutaneous aortic valve replacement

Background: Aortic stenosis (AS) is the most frequent valvular heart disease, and patients who develop AS are at a high risk of sudden death. There is no medical cure available, and aortic valve replacement is the only effective treatment for advanced disease. Preoperative evaluation is the cornerstone of therapy and is necessary for selecting the implantation technique and valve. Purpose: To evaluate the role of cardiac CT in comprehensive aortic valve and aortic root evaluation before percutaneous aortic valve replacement. Material and Methods: Thirty-four patients with severe aortic valve stenosis were evaluated by cardiac CT. The aortic valve calcification grade defined by cardiac CT was compared to the operative findings. The mean calculated aortic annulus diameter (CAAD) measured by cardiac CT was compared to the aortic annulus diameter measured by transthoracic echocardiography (TTE) as well as during the operation. The distances from the aortic valve annulus to the coronary ostia (right and left) were measured by cardiac CT and compared to the intraoperative measurements. The findings from the CT coronary angiography and conventional coronary angiography were compared. Results: There was strong agreement (k = 0.865) between the calcification grade by cardiac CT and the intraoperative grading. There was a stronger correlation (r = 0.948) between the CAAD assessed by cardiac CT and intraoperatively compared to the correlation between the intraoperative versus TTE measurements (r = 0.660). The distances measured between the aortic annulus and the right and left coronary artery ostia by cardiac CT were strongly correlated with the distances measured intraoperatively (r = 0.966 and 0.940 in the right and left sides, respectively). Cardiac CT detected three coronary artery stenotic lesions and three patent stents. All findings were confirmed by conventional coronary angiography. Thirteen percent of the evaluated coronary artery segments were of non-diagnostic quality by cardiac CT. Conclusion: Cardiac CT substantially facilitates the assessment of aortic root morphology prior to aortic valve replacement.