Three-dimensional thoracic aorta principal strain analysis from routine ECG-gated computerized tomography: feasibility in patients undergoing transcatheter aortic valve replacement

• Published in: BMC cardiovascular disorders Vol. 18; no. 1; p. 76
• Main Authors: Satriano, Alessandro, Guenther, Zachary, White, James A, Merchant, Naeem, Di Martino, Elena S, Al-Qoofi, Faisal, Lydell, Carmen P, Fine, Nowell M
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 02.05.2018; BioMed Central; BMC
• Subjects: 3-dimensional; Aged; Aged, 80 and over; Aorta, Thoracic - diagnostic imaging; Aorta, Thoracic - physiopathology; Aortic Valve - diagnostic imaging; Aortic Valve - physiopathology; Aortic Valve - surgery; Aortic valve stenosis; Aortic Valve Stenosis - diagnostic imaging; Aortic Valve Stenosis - physiopathology; Aortic Valve Stenosis - surgery; Aortography - methods; Cardiac-Gated Imaging Techniques; Computed Tomography Angiography; Computerized tomography; CT imaging; Diagnosis; Electrocardiogram; Electrocardiography; Feasibility Studies; Female; Heart valve replacement; Hemodynamics; Humans; Imaging, Three-Dimensional; Male; Models, Cardiovascular; Observer Variation; Patient-Specific Modeling; Predictive Value of Tests; Radiographic Image Interpretation, Computer-Assisted; Regional Blood Flow; Reproducibility of Results; Retrospective Studies; Severity of Illness Index; Strain; Stress, Mechanical; Transcatheter Aortic Valve Replacement; 3-dimensional; Transcatheter aortic valve replacement; Aortic valve stenosis; Computerized tomography; Strain
• ISSN: 1471-2261; 1471-2261
• DOI: 10.1186/s12872-018-0818-0

Functional impairment of the aorta is a recognized complication of aortic and aortic valve disease. Aortic strain measurement provides effective quantification of mechanical aortic function, and 3-dimenional (3D) approaches may be desirable for serial evaluation. Computerized tomographic angiography (CTA) is routinely performed for various clinical indications, and offers the unique potential to study 3D aortic deformation. We sought to investigate the feasibility of performing 3D aortic strain analysis in a candidate population of patients undergoing transcatheter aortic valve replacement (TAVR). Twenty-one patients with severe aortic valve stenosis (AS) referred for TAVR underwent ECG-gated CTA and echocardiography. CTA images were analyzed using a 3D feature-tracking based technique to construct a dynamic aortic mesh model to perform peak principal strain amplitude (PPSA) analysis. Segmental strain values were correlated against clinical, hemodynamic and echocardiographic variables. Reproducibility analysis was performed. The mean patient age was 81±6 years. Mean left ventricular ejection fraction was 52±14%, aortic valve area (AVA) 0.6±0.3 cm and mean AS pressure gradient (MG) 44±11 mmHg. CTA-based 3D PPSA analysis was feasible in all subjects. Mean PPSA values for the global thoracic aorta, ascending aorta, aortic arch and descending aorta segments were 6.5±3.0, 10.2±6.0, 6.1±2.9 and 3.3±1.7%, respectively. 3D PSSA values demonstrated significantly more impairment with measures of worsening AS severity, including AVA and MG for the global thoracic aorta and ascending segment (p<0.001 for all). 3D PSSA was independently associated with AVA by multivariable modelling. Coefficients of variation for intra- and inter-observer variability were 5.8 and 7.2%, respectively. Three-dimensional aortic PPSA analysis is clinically feasible from routine ECG-gated CTA. Appropriate reductions in PSSA were identified with increasing AS hemodynamic severity. Expanded study of 3D aortic PSSA for patients with various forms of aortic disease is warranted.