Dimensionless Index in Patients With Low-Gradient Severe Aortic Stenosis and Preserved Ejection Fraction

Background Risk stratification of patients with low-gradient (LG) severe aortic stenosis (AS) despite preserved left ventricular ejection fraction remains challenging. We sought to evaluate the relationship between the dimensionless index (DI)—the ratio of the left ventricular outflow tract time-velocity integral to that of the aortic valve jet—and mortality in these patients. Methods Seven hundred fifty-five patients with LG severe AS (defined by aortic valve area ≤1 cm 2 or aortic valve area indexed to body surface area ≤0.6 cm 2 /m 2 and mean aortic pressure gradient 2 (low flow, LF) or ≥35 mL/m 2 (normal flow, NF). Results After adjustment for age, sex, body mass index, Charlson comorbidity index, history of hypertension, history of atrial fibrillation, AS-related symptoms, left ventricular ejection fraction, indexed left ventricular ventricular mass, aortic valve area, and aortic valve replacement as a time-dependent covariate, patients with LG-LF and DIP P =0.003), and LG-LF and D≥0.25 (adjusted hazard ratio, 2.27 [95% CI, 1.42–3.63]; P Conclusions Among patients with LG severe AS and preserved left ventricular ejection fraction, decreased DI