Abstract Body (Do not enter title and authors here): Background: Aortic valve area planimetry (AVA_CT) is feasible on four-dimensional computed tomography (4D-CT) for grading aortic stenosis severity, with superior spatial but inferior temporal resolution to echocardiography, however its prognostic utility is not well-established. We evaluated the prognostic value of AVA_CT in patients with significant aortic valve stenosis undergoing transcatheter aortic valve replacement (TAVR).

Methods: We studied 1035 native aortic valve stenosis patients (age 79.0±9.0 years, 429 (41.5%) women) undergoing TAVR during 2019-2020. AVA_CT and indexed to body surface area (AVAi_CT) were retrospectively measured on contrast-enhanced 4D-CT at peak systole, and standard statistical analyses performed to evaluate its associations with all-cause mortality during follow-up.

Results: Mean AVA_CT and AVAi_CT were 1.02±0.21 cm² and 0.53±0.12 cm²/m² respectively, with 240 (23.2%) deaths during mean follow-up of 2.1±0.9 years. Areas under curves and optimal thresholds for identifying severe aortic stenosis (defined as AVA<1.0 cm² on echocardiography) were 0.78 and <1.10 cm² for AVA_CT and 0.83 and <0.65 cm²/m² for AVAi_CT. AVA_CT and AVAi_CT below these thresholds representing severe aortic stenosis were independently associated all-cause mortality during follow-up, with hazards ratios (95% confidence intervals) of 1.84 (1.34-2.53) and 2.38 (1.48-3.81) respectively in multivariable analyses. The Figure illustrates Kaplan-Meier survival curves for the cohort based on A) AVA_CT and B) AVAi_CT thresholds.

Conclusion: Optimal thresholds of AVA_CT (<1.10 cm²) and AVAi_CT (<0.65 cm²/m²) were independently associated with worse survival in patients undergoing TAVR, indicating that AVA_CT and AVAi_CT as potentially useful additional imaging biomarkers in the diagnostic and prognostic evaluation of aortic stenosis patients.