Abstract 16459: Underestimation of Aortic Stenosis Severity Using “Fusion” of Data From Computed Tomography and Doppler Echocardiography
Introduction: 2D-transthoracic echocardiography does not account for the elliptical anatomy of the left ventricular outflow tract (LVOT) and may thereby underestimate LVOT area. Fusion of Multidetector computed tomography (MDCT) -derived LVOT area and Doppler-derived flow data has been proposed to improve assessment of aortic valve area (AVA) and classification of stenosis severity. For fundamental hemodynamic reasons effective AVA has to be smaller than anatomical AVA allowing for testing of the validity of the “fusion-approach” by comparing effective MDCT-derived AVA with anatomic AVA from MDCT-planimetry.
Methods: In a total of 250 consecutive patients with aortic stenosis we retrospectively compared effective AVA (calculated from MDCT-LVOT and transthoracic Doppler measurements) with anatomic AVA based on MDCT planimetry.
Results: Mean age of the population under study was 81±5 years and 61% were female. Substituting the LVOT area from transthoracic echocardiography (TTE) by the MDCT-LVOT resulted in an increase of AVA from 0.74±0.15 to 0.92±0.18cm2 (p<0.01), which, counter-intuitively, was larger than anatomic AVA (0.82±0.15cm2; mean difference 0.10±0.16cm2) suggesting overcorrection. Similar results were obtained based on planimetry from transesophageal echocardiography (TEE; AVA 0.79±0.14cm2, p<0.01 vs. MDCT-LVOT; mean difference 0.13±0.16cm2) and in the subgroup of patients presenting with low gradient severe aortic stenosis and preserved ejection fraction (n=55, AVA from TTE 0.76±0.08; from MDCT-LVOT 0.97±0.14; MDCT planimetry 0.86±0.12; and TEE planimetry 0.84±0.13cm2).
Conclusion: Fusion of MDCT-derived LVOT area with Doppler echocardiography results in a calculated effective AVA that is larger than the corresponding anatomic AVA indicating underestimating of aortic stenosis severity by this method.
Author Disclosures: J. Minners: None. S. Dorfs: None. P. Ruile: None. F. Neumann: None. G. Pache: None. N. Jander: None.
- © 2016 by American Heart Association, Inc.