Clinical significance of dimensionless index in patients with low-gradient severe aortic stenosis and preserved ejection fraction

Background Risk assessment of patients with low-gradient severe aortic stenosis (LG-SAS) despite preserved left ventricular ejection fraction (LVEF) remains challenging. Purpose To evaluate the relationship between the Dimensionless Index (DI) – the ratio of the left ventricular outflow tract (LVOT) time-velocity integral to that of the aortic valve jet – and mortality in patients with LG-SAS and preserved LVEF. Methods In total, 755 patients with LG-SAS (defined by AVA ≤ 1 cm2 and/or AVAi ≤ 0.6 cm2/m2 and mean aortic pressure gradient   35 mL/m2 (normal flow [NF]). Results After adjustment for age, gender, body mass index, Charlson Comorbidity Index, history of hypertension, documented coronary artery disease, history of atrial fibrillation, AS-related symptoms, LVEF, indexed LV ventricular mass, aortic valve area (AVA), and aortic valve replacement (AVR) as a time dependent covariate, patients with LG-LF and DI  Fig. 1 ). Conclusion Among patients with LG severe AS and preserved LVEF, decreased DI