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Combined Value of Dimensionless Index and Transvalvular Flow Rate in Risk Stratification of Aortic Stenosis
Mayooran Namasivayam1, Timothy W Churchill2, Romain Capoulade3
1Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Cardiology, St. Vincent's Hospital, and Heart Valve Disease and Artificial Intelligence Laboratory, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; Faculty of Medicine and Health, University of New South Wales, Sydney, Australia.
Abstract:
Aortic stenosis (AS) is difficult to phenotype. The metrics of severity are frequently discordant, making prognostication challenging. Flow state is central to accurately determining severity. We sought to evaluate the prognostic value of dimensionless index (DI) and transvalvular flow rate (Q) in AS. We evaluated 2 independent, longitudinal registries of ≥ moderate severity AS (aortic valve area ≤1.5 cm2 or mean gradient ≥20 mm Hg) with complete data follow-up. In the primary cohort (n = 1,104, 77 ± 11 years, 40% female), the DI and Q category significantly predicted mortality (p <0.001) (Figure 1), with the highest risk being low DI and low Q (DI <0.25, Q ≤210 mL/s). In the validation cohort (n = 939, 70 ± 13 years, 42% female), similar results were seen in Kaplan-Meier (p <0.001) and multivariable Cox model analyses (p <0.01). We advocate for wider combined use of DI and Q in AS assessment to augment current diagnostic and prognostic approaches.
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