Patient Prosthesis Mismatch and Prosthetic Valve Implant Size Are not Accurately Predicted by Pre-operative Multidetector Computed Tomography

Abstract

Objective: Multidetector computed tomography (MDCT) is vital in preoperative sizing for transcatheter aortic valve replacement (TAVR), while SAVR prosthesis size is determined intraoperatively by direct measurement. Preoperative SAVR sizing would assist in identifying patients at risk for PPM, and in predicting whether aortic root enlargement may be necessary. The purpose of this study is to determine if TAVR MDCT accurately predicts SAVR prosthesis size, and possibly PPM. Methods: In this study, 184 patients who underwent SAVR between July 2012-July 2019 were retrospectively analyzed. 123 patients had preoperative MDCT for aortic annular sizing. Measurements were stratified into 2mm increments to determine if MDCT size correlated with implanted SAVR prosthesis size. Measurements within 1mm of implanted prosthesis size were considered accurate. Patients with inaccurate measurements were recorded as having an implanted aortic valve prosthesis that was either larger or smaller than the MDCT size. Results: 65 patients (52.8%) had preoperative MDCT measurements that were accurate. 22 patients (17.9%) had implanted prosthetic valves that were larger than their MDCT measurements and 36 patients (29.3%) had implanted prosthetic valves that were smaller. Patients with the smallest annular measurements were more likely to have larger implanted valves than the MDCT-measured annulus, while patients with the largest measurements were more likely to have smaller implanted valves (p<0.0001). 108 patients were assessed for PPM. 14 patients (13%) exhibited PPM, 9 (64%) were correctly predicted by MDCT measurements. Conclusions: MDCT is not accurate in predicting SAVR size. Patients with smaller annular measurements were more likely to be undersized by MDCT, while patients with larger annular measurements were more likely to be oversized. PPM was inconsistently predicted by MDCT in SAVR.