Correlation between fluoroscopy and tomographic aortic-root measurements in the decision of the transcatheter heart valve size in patients undergoing transcatheter aortic valve implantation
Authors: Alvarez-Covarrubias H A , Michel J , Xhepa E , Mayr N P , Pellegrini C , Rheude T , Kasel A M , Joner M , Borrayo-Sanchez G 
Published: October 2021

Abstract

Introduction and hypothesis
Transcatheter aortic valve implantation (TAVI) has become the standard treatment in intermediate and high-risk patients with high degree aortic stenosis (AS).(1–2) These has been also extended to low-risk and younger patients.(3–5) Besides the use of computed-tomography (CT) as diagnostic method to measure the aortic anatomy for transcatheter heart valve (THV) size decision and the radiation exposure (RE) during TAVI, younger patients are more exposed to radiation and contrast media (CM) complications due to a potentially second procedure.(6) Reducing RE and CM using only angiography aortic measurement could reduce the risk of RE and CM related complications without compromising the efficacy of the THV. We hypothesize that angiographic aortic root (AR) measure has good correlation with CT measure without compromising safety and efficacy of the THV.

Methods
Observational analysis: 1250 transfemoral TAVI patients with balloon or self-expandable valves were included. Aortic root CT measurement was done in all patients. AR measurement using Follow the right cup rule (7) was additionally done in 505 patients. Correlation between CT only (Group I n=745) versus CT and AR measurement (Group II n=505) was done. An inter and intraobserver validation analysis was done. Primary endpoint was VARC-2 device success. Secondary safety endpoints were composite of in-hospital and 30-days complications.

Results
Really good intra (0.86, p&lt;0.001) and interobserver (0.81, p&lt;0.001) correlation between CT (mean aortic diameter, distance between non (NC-HP) and left cusp hinge points (LC-HP) distance) and angiographic (LC-HP distance) measurements was observed. CT and AR measurement had a very good correlation between the two groups (CT mean aortic diameter vs CT NC-HP and LC-HP distance, 0.724 p&lt;0.001; CT NC-HP and LC-HP distance vs angiographic NC-HP and LC-HP distance manual calibration 0.808 p&lt;0.001; angiographic NC-HP and LC-HP distance manual calibration vs angiographic NC-HP and LC-HP distance automatic calibration 0.930 p&lt;0.001). No differences in primary endpoint were observed between groups (device success Group I 98% vs Group II 99%, p 0.18). In-hospital complications were similar between two groups except in major bleeding (13% vs 19%, p 0.004), major vascular (10.9% vs 16.6%, p 0.004) and minor vascular (14% vs 21%, p 0.001) between group I and II respectively. Valve safety (86% vs 77%, p&lt;0.001, OR 0.89, 95% CI 0.85–0.95) and clinical efficacy (84% vs 60.8%, p&lt;0.001, OR 0.72, 95% CI 0.67–0.77) at 30 days were more common in group II. No difference in valve dysfunction was observed (Group I 10.3% vs Group II 7.3%, p 0.042, OR 1.41, 95% CI 0.97–2.05).

Conclusions
Compared to CT, AR measurement is a good option selecting THV size. No differences regarding device success and in-hospital and 30 days follow-up complications were observed. AR measurement could replace CT in specific cases.

Funding Acknowledgement
Type of funding sources: None. Angiographic and CT measurementsEndpoints