Determinants of left atrial volume index in patients with aortic stenosis: A multicentre pilot study

Left atrial (LA) enlargement is frequent in patients with aortic stenosis (AS), yet its determinants and prognostic implications are poorly understood.

To identify the echocardiographic variables associated with increased LA volume index (LAVI), and test the prognostic value of LAVI in AS.

We prospectively included 715 patients with AS in sinus rhythm at enrolment. Echocardiography was performed at baseline. Median follow-up was 22.0 (9-34) months. Patients were divided into two groups according to the best cut-off for event prediction during follow-up (45mL/m²).

Compared with LAVI<45mL/m², patients with LAVI≥45mL/m² had a lower stroke volume, cardiac output and left ventricular (LV) ejection fraction, greater LV volumes and mass and higher filling pressures. By linear regression, LAVI was best correlated with E wave mitral velocity (r=0.34), E/A ratio (r=0.34), E/e' ratio (r=0.28), indexed LV mass (r=0.29), systolic pulmonary artery pressure (r=0.34) and LV longitudinal strain (r=-0.28). Multivariable analysis confirmed the independent association of LAVI with age (P<0.001), indexed aortic valve area (P=0.04), indexed LV mass (P<0.001), LV ejection fraction (P=0.007), LV end-diastolic volume (P=0.001), E/A ratio (P<0.001) and E/e' ratio (P<0.001). LAVI≥45mL/m² was independently predictive of the combined endpoint of cardiovascular death or hospitalization for heart failure (adjusted hazard ratio 1.69, 95% confidence interval 1.04-2.73).

LA enlargement is correlated with AS severity, but also with variables reflecting LV systolic and diastolic dysfunction. Further studies are needed to investigate the outcome implication of LA enlargement in patients with AS.