BackgroundThe prognostic impact of increased left atrial (LA) volume in mild-to-moderate aortic valve stenosis (AS) is unclear. We investigated the association of estimated LA volume with prognosis in a large prospective study of patients with asymptomatic mild-to-moderate AS. MethodsThe association of estimated LA volume with major cardiovascular events (MACE, combined cardiovascular death, heart failure hospitalization and non-hemorrhagic stroke) was assessed in 1534 patients with initially mild-to moderate asymptomatic AS, participating in the Simvastatin Ezetimibe in Aortic Stenosis study for a median of 4.3 years. LA volume was estimated from LA diameter applying a validated nonlinear equation and indexed to body height in meters squared (eLAVI). An enlarged eLAVI was identified by using sex-specific cut-offs (>19 ml/height2 in men and >17 ml/height2 in women). ResultsPatients with enlarged eLAVI were older, more obese, and had higher systolic blood pressure and left ventricular (LV) mass index (all p < 0.001). During follow-up, incident MACE occurred in 137 patients, more often in patients with enlarged eLAVI (20% vs. 7.7%, p < 0.001). Using aortic valve replacement as a competing risk event, enlarged eLAVI at baseline predicted increased hazard rate (HR) of MACE (HR 2.21 [95% confidence interval 1.37–3.55], p = 0.001) independent of significant associations with presence of LV hypertrophy, older age, higher peak aortic jet velocity, serum creatinine and lower LV ejection fraction and stroke volume. ConclusionsPresence of enlarged eLAVI was independently associated with increased risk of MACE in patients with mild-to moderate asymptomatic AS.