Energy-loss index does not improve risk prediction in aortic stenosis compared to conventional aortic valve area assessment

BackgroundEvidence of improved risk assessment in aortic stenosis (AS) by using energy-loss index (ELI) instead of aortic valve area indexed to body surface area (AVAi) is scarce, and positive results have been driven by aortic valve replacement. We aimed to evaluate the prognostic performance of ELI and AVAi in a head-to-head comparison using large-scale, real-world data. MethodsIn the multi-center, mortality-data linked National Echocardiography Database of Australia (NEDA), patients with AS and requisite ascending aortic area measurements were identified. The prognostic value of AVAi and ELI, respectively, was analyzed using Cox regression and the C statistic. ResultsIn patients with mild AS (n=3,179), moderate AS (n=4,194), and severe AS (n=3,120), there were 4,229 deaths of which 2,359 were reported as cardiovascular deaths (median [interquartile range] follow-up 2.5 [1.1-4.5] years]. Decreasing AVAi was associated with increased cardiovascular mortality (hazard ratio [95% confidence interval] 1.18 [1.16- 1.20] per 0.1 cm2/m2 downward increment]. Prognostic performance for 5-year mortality did not improve by using ELI instead of AVAi (identical C statistics 0.626 [0.612-0.640]), and the relative performance did not change when analyzing 1-year cardiovascular mortality, or all-cause mortality. ConclusionELI was not associated with improved prognostic performance compared to AVAi in echocardiographic assessment of AS using large-scale, real-world clinical data. AVAi remains a relevant measure for risk prediction in AS, providing information on incremental risk with decreasing area.