Calculating aortic valve area using a hybrid CT-echocardiography method reclassified 29% of TAVR patients from severe to moderate aortic stenosis.
Observational (n=1,461)
No
Does hybrid-AVA calculation using CT-derived LVOT area reclassify severe aortic stenosis to moderate aortic stenosis compared to standard echocardiography in TAVR patients?
Using a hybrid CT-echocardiography approach for calculating aortic valve area reclassifies nearly 30% of TAVR patients—and 47% of those with low-gradient AS—from severe to moderate aortic stenosis.
Abstract Introduction Echocardiography (echo) may underestimate aortic valve area (AVA) due to the anatomic shape of left ventricular outflow track (LVOT). Using cardiac CT derived LVOT area in the continuity equation (hybrid-AVA) may result in reclassification of patients with severe aortic stenosis (AS) to moderate AS. Aim Our aim was to evaluate the reclassification rate of severe AS to moderate AS by hybrid-AVA, and identify potential predictors of reclassification. Methods We retrospectively analyzed consecutive patients with severe AS (echo-AVA 1cm2) who underwent transcatheter aortic valve replacement (TAVR) in our tertiary cardiovascular center between 01.01.2020 - 01.09.2024. Hybrid-AVA was calculated by combining CT-based LVOT area and echo Doppler parameters. Patients with hybrid-AVA 1cm2 were reclassified to moderate AS. Patients were divided into two groups: Group 1: aortic mean gradient ≥40 mmHg, Group 2: aortic mean gradient 40 mmHg. Bland-Altman analysis was used to evaluate the systematic differences between echo and CT measurements, while logistic regression was used to identify potential predictors of reclassification. Results Overall 1461 patients were analyzed (698men, mean age: 79.0±6.7years). Patients in group 1 (n= 1066) were older (79.4 ± 6.4 yrs vs 77.8 ± 7.3 yrs; p0.001) female sex were more prevalent (57% vs 39 %; p0.001) than in group 2 (n=395). In the entire group echo-LVOT diameter (20.36 ± 1.98 mm) was significantly smaller than the mean (25.10 ± 2.96mm) maximum (28.65 ± 3.34 mm) or either the minimum (21.55 ± 2.93 mm) CT-LVOT diameter (0.001 for all). The calculated echo LVOT area was also smaller than the measured CT LVOT area (328.8 ± 65.1 mm2 ± 487.7 ± 120.8 mm2; p0.001). Bland-Altman analysis showed that the mean difference between echo-AVA and hybrid-AVA was -0.29±0.19cm2 (ULoA: 0.08 cm2; LLoA: -0.66cm2). Implementing hybrid-AVA 421 patients (29%) were reclassified into moderate AS; significantly larger portion in group 2 than in group 1 (47% vs 23%; p0.001). Multivariable logistic regression showed that male sex (OR:3.82 2.75-5.34; p0.001), ejection fraction (per%; OR: 0.98 0.97-0.99; p0.001),Doppler index (LVOT-VTI/Ao-VTI per 0.1; OR:1.20 1.16-1.24; p0.001), and low flow state (SVi35 mL/m2; OR: 0.55 (0.38-0.79), p=0.001) were independent factors of reclassification. Conclusions The hybrid-AVA calculation led to reclassification of almost 30% of TAVR patients from severe to moderate AS. In patients with low mean aortic gradient reclassification affects almost half of the patients. Male sex, ejection fraction, low flow state, and Doppler index may be potential predictors of reclassification.Bland-Altman plot of hybrid vs echo AVA
Mohacsi et al. (2026) conducted an observational in Severe aortic stenosis (n=1,461). Hybrid-AVA calculation (CT-based LVOT area and echo Doppler) vs. Standard echocardiography (echo-AVA) was evaluated on Reclassification from severe to moderate aortic stenosis. Calculating aortic valve area using a hybrid CT-echocardiography method reclassified 29% of TAVR patients from severe to moderate aortic stenosis.