Please use this identifier to cite or link to this item: http://bura.brunel.ac.uk/handle/2438/19226
Title: Inconsistency in aortic stenosis severity between CT and echocardiography: Prevalence and insights into mechanistic differences using computational fluid dynamics
Authors: Mittal, TK
Reichmuth, L
Bhattacharyya, S
Jain, M
Baltabaeva, A
Rahman Haley, S
Mirsadraee, S
Panoulas, V
Kabir, T
Nicol, ED
Dalby, M
Long, Q
Issue Date: 29-Jul-2019
Publisher: BMJ Publishing Group
Citation: Open Heart, 2019, 6 (2)
Abstract: © 2019 Author(s). Objectives The aims of this study were to evaluate the inconsistency of aortic stenosis (AS) severity between CT aortic valve area (CT-AVA) and echocardiographic Doppler parameters, and to investigate potential underlying mechanisms using computational fluid dynamics (CFD). Methods A total of 450 consecutive eligible patients undergoing transcatheter AV implantation assessment underwent CT cardiac angiography (CTCA) following echocardiography. CT-AVA derived by direct planimetry and echocardiographic parameters were used to assess severity. CFD simulation was performed in 46 CTCA cases to evaluate velocity profiles. Results A CT-AVA>1 cm 2 was present in 23% of patients with echocardiographic peak velocity≥4 m/s (r=-0.33) and in 15% patients with mean Doppler gradient≥40 mm Hg (r=-0.39). Patients with inconsistent severity grading between CT and echocardiography had higher stroke volume index (43 vs 38 mL/m 2, p<0.003) and left ventricular outflow tract (LVOT) flow rate (235 vs 192 cm 3/s, p<0.001). CFD simulation revealed high flow, either in isolation (p=0.01), or when associated with a skewed velocity profile (p=0.007), as the main cause for inconsistency between CT and echocardiography. Conclusion Severe AS by Doppler criteria may be associated with a CT-AVA>1 cm 2 in up to a quarter of patients. CFD demonstrates that haemodynamic severity may be exaggerated on Doppler analysis due to high LVOT flow rates, with or without skewed velocity profiles, across the valve orifice. These factors should be considered before making a firm diagnosis of severe AS and evaluation with CT can be helpful.
URI: http://bura.brunel.ac.uk/handle/2438/19226
DOI: http://dx.doi.org/10.1136/openhrt-2019-001044
ISSN: http://dx.doi.org/10.1136/openhrt-2019-001044
2053-3624
http://dx.doi.org/10.1136/openhrt-2019-001044
2053-3624
2053-3624
http://dx.doi.org/10.1136/openhrt-2019-001044
2053-3624
Appears in Collections:Dept of Mechanical and Aerospace Engineering Research Papers

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