Discordant grading in severe aortic stenosis (AS) has well-known prognostic repercussions. The incidence of various flow-gradient patterns and the consequences for prognosis in mild AS remained unclear, though. For a study, researchers sought to investigate the incidence and prognostic consequences of various flow-gradient patterns in patients with moderate AS.

According to transvalvular mean gradient (MG), stroke volume index (SVi), and left ventricular ejection fraction (LVEF), patients with moderate AS (aortic valve area >1.0 and ≤1.5 cm2 were identified and divided into 4 groups: concordant moderate AS (MG ≥20 mm Hg) and discordant moderate AS, which included 3 subgroups: normal-flow, low-gradient moderate AS (MG <20 mm Hg, SVi ≥35 mL/m2, and LVEF ≥50%); Both “traditional” low-flow, low-gradient moderate AS (MG <20 mm Hg and LVEF <50%) and “paradoxical” low-flow, low-gradient moderate AS (MG <20 mm Hg, SVi <35 mL/m2, and LVEF ≥50%) are examples of low-flow, low-gradient moderate AS. All-cause mortality served as the main outcome.

About 788 (40%) of 1,974 patients (age 73±10 years; 51% men) with moderate AS had grading that was not consistent, and these patients had substantially higher death rates (P<0.001) than those with concordant moderate AS. The “classical” low-flow, low-gradient (HR: 1.710; 95% CI: 1.270-2.303; P<0.001) and “paradoxical” low-flow, low-gradient patterns (HR: 1.458; 95% CI: 1.072-1.983; P=0.014), but not the normal-flow, low-gradient mild AS pattern, were independently related to all-cause mortality on multivariable analysis and death.

Patients with mild AS commonly (40%) experience discordant grading. A major fraction of the discordant instances were caused by low-flow, low-gradient patterns, which were also linked to higher mortality. These results highlighted the need for more accurate phenotyping of patients with moderately discordant AS.

Reference: jacc.org/doi/10.1016/j.jacc.2022.05.036