Characterization of aortic root geometry in transcatheter aortic valve replacement patients.

PURPOSE: The study aimed to characterize the geometry of the aortic root pre- and post-transcatheter aortic valve replacement (TAVR) and investigate differences in pre- and post-TAVR anatomy. BACKGROUND: A greater understanding of how aortic root geometry changes after TAVR is needed to facilitate further investigation into the hemodynamic profiles of the post-TAVR aortic root. METHODS: Anatomical measurements were conducted on de-identified, retrospective post-TAVR 4DCT scans of 109 patients with aortic stenosis obtained from the RESOLVE study. The diameter of the aortic root was measured at the level of the annulus, left ventricular outflow tract (LVOT), sinus of Valsalva, sinotubular junction (STJ) and ascending aorta. The heights of the STJ and coronary arteries were also measured. RESULTS: All aortic root dimensions were normally distributed across the cohort and changed significantly between pre- and post-TAVR conditions (P < 0.01). Post-TAVR dimensions changed significantly from peak systole to end diastole (P < 0.01). Regression models were obtained for all aortic root dimensions in terms of annulus diameter with excellent coefficient of determination (R2 > 0.95, P < 0.001). CONCLUSIONS: There are significant differences between pre- and post-TAVR as well as peak systolic and end diastolic aortic root anatomy. Appropriate anatomical dimensions should be selected for benchtop testing as the geometry varies greatly throughout the cardiac cycle.