Three-dimensional echocardiography vs. computed tomography for transcatheter aortic valve replacement sizing

Area of Science:

• Cardiology
• Medical Imaging
• Interventional Cardiology

Background:

• Accurate sizing of the aortic annulus is critical for successful transcatheter aortic valve replacement (TAVR).
• Multi-slice computed tomography (MSCT) is considered the gold standard for pre-procedural TAVR sizing.
• The accuracy of three-dimensional transoesophageal echocardiography (3D-TEE) for TAVR sizing compared to MSCT is not well-established.

Purpose of the Study:

• To compare aortic annulus measurements obtained by 3D-TEE with those from MSCT in patients undergoing TAVR.
• To evaluate the potential impact of 3D-TEE measurements on transcatheter heart valve (THV) size selection.

Main Methods:

• A prospective cohort study included 53 consecutive patients undergoing TAVR with both MSCT and 3D-TEE for aortic annulus sizing.
• Aortic annular dimensions, predicted THV oversizing, and hypothetical valve size selection were compared between the two imaging modalities.
• Correlation and agreement analyses were performed for diameter, perimeter, and area measurements.

Main Results:

• 3D-TEE and MSCT measurements showed moderate to high correlation for diameter (r=0.69), perimeter (r=0.70), and area (r=0.67).
• 3D-TEE measurements were significantly smaller than MSCT (perimeter: 68.6 vs. 75.1 mm; area: 345.6 vs. 426.9 mm²).
• Using 3D-TEE measurements could result in inappropriate valve size selection for up to 50% of patients based on manufacturer algorithms.

Conclusions:

• Aortic annulus measurements by 3D-TEE are significantly smaller than MSCT for TAVR planning.
• This size discrepancy has the potential to lead to incorrect THV sizing in a substantial proportion of patients.
• 3D-TEE should be considered for TAVR sizing only when MSCT is unavailable or contraindicated, pending further clinical impact studies.