Computed tomography angiography is not accurate in predicting surgical prosthetic aortic valve implant size.

BACKGROUND: Multidetector computed tomography is vital in preoperative sizing for transcatheter aortic valve replacement. The purpose of this study is to determine whether preoperative transcatheter aortic valve replacement multidetector computed tomography accurately predicts surgical aortic valve prosthesis size. METHODS: Between July 2012 and July 2017, 102 patients who underwent surgical aortic valve replacement had preoperative aortic valve sizing by multidetector computed tomography. The aortic annulus diameter calculated using multidetector computed tomography was compared with intraoperative valve sizing during surgical aortic valve replacement. RESULTS: Forty-one (40.2%) of the 102 patients studied had multidetector computed tomography aortic valve measurements that were accurate. Implanted valves were smaller than multidetector computed tomography calculation in 40 patients (39.2%) and were larger in 21 patients (20.6%). Multidetector computed tomography measurements remained inconsistent with intraoperative sizing regardless of aortic annulus diameter. The variance between multidetector computed tomography annulus measurements and intraoperative sizing was statistically significant. CONCLUSIONS: Preoperative aortic annulus measurements by our institutional transcatheter aortic valve replacement multidetector computed tomography protocol differed substantially from surgical implant size. There was no trend toward over nor under sizing for the entire cohort. However, patients with large measured annulus diameter were more likely to have a smaller valve implanted than predicted, and patients with small measured annulus diameter were more likely to have a larger valve implanted than predicted. These results may affect preoperative planning for patients undergoing aortic valve replacement.