Value of Transvalvular Flow Rate during Exercise in Asymptomatic Patients with Aortic Stenosis

Abstract

The optimal management of asymptomatic aortic stenosis (AS) remains controversial. Although exercise stress echocardiography (ESE) has been applied to nonischemic heart disease, the evidence of the prognostic value for asymptomatic AS has been limited. This study aimed to investigate the value of ESE in patients with asymptomatic AS. This retrospective observational study included consecutive asymptomatic patients with at least moderate AS (mean pressure gradient≥20mm Hg or aortic valve area < 1.5cm2) and preserved left ventricular ejection fraction (≥50%) who underwent ESE. Of these, 10 patients who were referred for aortic valve replacement without symptoms were excluded. A final 99 conservatively managed patients (73±13years; 54% male) were enrolled in this study. All patients were followed for AS-related events. During the mean follow-up period of 14±11months, 23 patients underwent from AS-related events. Although no differences were found between the patients with and without adverse events in terms of mean pressure gradient during exercise, the transvalvular flow rate during exercise (Ex-FR) was lower in the patients who experienced adverse events (236±55 vs 274±64mL/sec, P=.01). Multivariate Cox regression analysis showed a decrease in Ex-FR (<270mL/sec) independently associated with adverse events in patients with asymptomatic AS (hazard ratio=3.53, P<.01). The result of the present study suggests that Ex-FR measured by ESE could play a crucial role in the risk stratification of patients with asymptomatic AS.