Prognostic Value of the Mitral E/e' Ratio During Exercise in Asymptomatic Patients With Low-gradient Severe Aortic Stenosis and Preserved Ejection Fraction

BackgroundCurrent evidence on the prognostic value of exercise stress echocardiography (ESE) in asymptomatic patients with low-gradient severe AS is limited. Therefore, this study aimed to elucidate its prognostic implications for patients with low-gradient severe AS and determine the added value of ESE in risk stratification for this population. MethodsThis retrospective observational study included 122 consecutive asymptomatic patients with either moderate (mean pressure gradient [MPG] <40 mmHg and aortic valve area [AVA] 1.0-1.5 cm2) or low-gradient severe (MPG <40 mmHg and AVA <1.0 cm2) AS and preserved left ventricular ejection fraction ([&ge;]50%) who underwent ESE. All patients were followed up for AS-related events. ResultsOf 143 patients, 21 who met any exclusion criteria, including early interventions, were excluded, and 122 conservatively managed patients (76.5 [71.0-80.3] years; 48.3% male) were included in this study. During a median follow-up period of 989 (578-1571) days, 64 patients experienced AS-related events. Patients with low-gradient severe AS had significantly lower event-free survival rates than those with moderate AS (log-rank test, p<0.001). Multivariable Cox regression analysis showed that the mitral E/e ratio during exercise was independently associated with AS-related events (hazard ratio=1.075, p<0.001) in patients with low-gradient severe AS. ConclusionsThis study suggests that asymptomatic patients with low-gradient severe AS have worse prognoses than those with moderate AS. Additionally, the mitral E/e ratio during exercise is a useful parameter for risk stratification in patients with low-gradient severe AS. Clinical PerspectiveAortic stenosis (AS) is increasingly prevalent in aging society, and risk stratification of patients with low-gradient severe AS and preserved ejection fraction remains controversial. Exercise testing has been useful for identifying symptoms or abnormal hemodynamic responses during exercise in patients with asymptomatic AS. Limited evidence supports exercise stress echocardiography (ESE) as a valuable tool for evaluating asymptomatic AS. This study investigated the prognoses of patients with low-gradient severe AS and the utilization of ESE for risk stratification of these patients. Patients with low-gradient severe AS had worse prognoses than those with moderate AS. The mitral E/e ratio during exercise can be utilized as a parameter for risk stratification of patients with low-gradient severe AS.