Evaluation of the interest of the scanner to measure the surface of the aortic stenosis by planimetry: A retrospective monocentric diagnostic study compared to the echocardiography

Introduction In aortic stenosis (AS), the orifice area is usually evaluated by ultrasound using the continuity equation. The objective of this study is to evaluate the interest of measurement of the aortic surface by planimetry with the scanner. Methods This retrospective single-center study focused on 127 patients with symptomatic tight RA who were referred to a TAVI between January 2017 and February 2018. On CT, the valvular calcium score and the aortic area (by planimetry) were evaluated. On ultrasound, performed for each patient as the CT scan, the aortic area and the mean gradient were also measured. Concordance between CT and ultrasound to estimate the aortic area was evaluated by a Bland and Altman test. Correlations between the different measured parameters were performed by a Spearman test. Results The average aortic area measured by ultrasound was 0.77 ± 0.16 cm2. The mean aortic area measured by planimetry on CT was 1.11 ± 0.24 cm2. Aortic CT overestimated the mean aortic area by 0.33 ± 0.26 cm2 compared to ultrasound (P  Conclusions The results of our study suggest that the measurement of the aortic surface by planimetry at the cardiac scanner has a very poor agreement with that measured by ultrasound and is not correlated with calcium score in patients with tight RA directed towards a TAVI.