Three-D measurements of LVOT: impact on quantification of aortic stenosis (AS)

Abstract

Abstract Background Discrepancies between aortic valve area (AVA) and gradients are recognized in patients with AS and normal LVEF and can impact on surgical referral decisions. Purpose Pilot study to determine whether using 3D rather than 2D LVOT dimensions leads to fewer discrepancies and less patients diagnosed with severe AS by continuity equation. Methods AS was quantified as per BSE guidelines in 55 consecutive patients (M: 32, age: 73±10) with LVEF>50% and at least moderate AS by AVA. LVOT was imaged with 3D zoom and its two orthogonal diameters were used to calculate the LVOT area for the continuity equation. Results Severe AS was diagnosed by AVA in 24/55 (44%) patients (Table 1). By 3D measurements the LVOT eccentricity index (D1/D2) was 0.8±0.1 and the LVOT area and SVi were larger than the ones calculated by 2D measurements:3.74±0.7 cm2 vs. 3.29±0.5 cm2 and 51.4±13 ml/BSA, vs. 45.3±9 ml/BSA, respectively, p<0.05. 3D measurements reduced the number of severe AS cases from 24 to 18 (AVA) and from 33 to 24 (AVAi) (25% and 27% respectively, p<0.05). AS severity agreement for all parameters slightly improved from 34/55 (62%) to 37/55/ (67%), p: ns Conclusions 1) In this pilot study, the use of 3D-derived LVOT measurements reduced by 25% the frequency of severe AS diagnosis. 2) If these results are confirmed in larger studies, use of 3D LVOT measurements may become standard of practice. Funding Acknowledgement Type of funding source: None