PhD Scientific Days 2024

Cardiovascular Medicine and Research I.

Reclassification From Severe To Moderate Aortic Stenosis Using Hybrid-AVA Technique In TAVR Patients

Text of the abstract

Introduction: Echocardiography (echo) may underestimate aortic valve area (AVA) due to the anatomic shape of leftventricular 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.
Aims: Our aims were 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 06.01.2021-27.02.2023. Hybrid-AVA was calculated by combining CT-based LVOT area and echo Doppler parameters. Patients with hybrid-AVA >1cm2 were reclassified to moderate AS. 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, 706 patients were analyzed (337 men, mean age: 79.1±7=6.9 years). Echo LVOT diameter (20.2±1.9 mm) was significantly smaller than the mean (25.1±2.9 mm) CT-LVOT diameter (<0.0001 for all). Bland-Altman analysis showed that the mean difference between echo-AVA and hybrid-AVA was -0.30±0.19 cm2 (LOA: -0.66; 0.07 cm2). Implementing hybrid-AVA, 200 patients (28.3%) were reclassified into moderate AS. Multivariable logistic regression showed that male sex (aOR: 6.73 [95%CI: 3.62; 13.00]; p<0.0001), ejection fraction (per %; aOR: 0.95 [95%CI: 0.93; 0.97]; p<0.0001), Doppler index (LVOT-VTI/Ao-VTI per 0.1; aOR: 1.50 [95%CI: 1.13;1.28]; p<0.0001), low gradient (<40mmHg; aOR: 1.95 [95%CI: 1.10; 3.46]; p<0.02) and low flow (<35 mL/m2; aOR: 0.37 [95%CI: 0.17; 0.77], p<0.01) significantly increased the odds of reclassification.
Conclusions: The hybrid-AVA calculation led to reclassification of almost 30% of TAVR patients from severe to moderate AS. Male sex, ejection fraction, low flow, low gradient, and Doppler index may be potential predictors of reclassification.
Funding: no fundings used.