Prevalence and Prognostic Implications of Discordant Grading and Flow-Gradient Patterns in Moderate Aortic Stenosis

Abstract

BACKGROUND The prognostic implications of discordant grading in severe aortic stenosis (AS) are well known. However, the prevalence of different flow-gradient patterns and their prognostic implications in moderate AS are unknown. OBJECTIVES The purpose of this study was to investigate the occurrence and prognostic implications of different flow-gradient patterns in patients with moderate AS. METHODS Patients with moderate AS (aortic valve area >1.0 and <= 1.5 cm(2)) were identified and divided in 4 groups based on transvalvular mean gradient (MG), stroke volume index (SVi), and left ventricular ejection fraction (LVEF): concordant moderate AS (MG >= 20 mm Hg) and discordant moderate AS including 3 subgroups: normal-flow, lowgradient moderate AS (MG <20 mm Hg, SVi >= 35 mL/m(2), and LVEF >= 50%); "paradoxical" low-flow, low-gradient moderate AS (MG < 20 mm Hg, SVi <35 mL/m(2), and LVEF >= 50%) and "classical" low-flow, low-gradient moderate AS (MG <20 mm Hg and LVEF <50%). The primary endpoint was all-cause mortality. RESULTS Of 1,974 patients (age 73 +/- 10 years, 51% men) with moderate AS, 788 (40%) had discordant grading, and these patients showed significantly higher mortality rates than patients with concordant moderate AS (P < 0.001). On multivariable analysis, "paradoxical" low-flow, low-gradient (HR: 1.458; 95% CI: 1.072-1.983; P = 0.014) and "classical" low-flow, low-gradient (HR: 1.710; 95% CI: 1.270-2.303; P < 0.001) patterns but not the normal-flow, low-gradient moderate AS pattern were independently associated with all-cause mortality. CONCLUSIONS Discordant grading is frequently (40%) observed in patients with moderate AS. Low-flow, lowgradient patterns account for an important proportion of the discordant cases and are associated with increased mortality. These findings underline the need for better phenotyping patients with discordant moderate AS. (C) 2022 by the American College of Cardiology Foundation.