Abstract 4122134: Relationships between aortic valve area planimetry on four-dimensional cardiac computed tomography and survival following transcatheter aortic valve replacement

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 cm 2 and 0.53±0.12 cm 2 /m 2 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 cm 2 on echocardiography) were 0.78 and <1.10 cm 2 for AVA CT and 0.83 and <0.65 cm 2 /m 2 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 cm 2 ) and AVAi CT (<0.65 cm 2 /m 2 ) 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.