SGLT2 inhibitors and left atrial function in heart failure with reduced or mildly reduced ejection fraction

Sodium-glucose cotransporter-2 (SGLT2) inhibitors reduce cardiovascular mortality and hospitalizations in heart failure (HF). However, their effects on left atrial (LA) structure and function remain unclear, particularly in patients with reduced or mildly reduced ejection fraction (EF).

This observational, cross-sectional study included 134 patients with HF and EF < 50%, divided into two groups: those receiving SGLT2 inhibitors (SGLT2+, n = 25) and those not receiving them (SGLT2-, n = 109). Echocardiographic measurements of LA volume index (LAVI), LA emptying fraction (LAEF), LA functional index (LAFI), and passive/active emptying fractions were obtained according to ASE/EACVI guidelines. Clinical, laboratory, and echocardiographic parameters were compared between groups, and correlations with LA indices were analyzed using multivariable linear regression.

The prevalence of diabetes mellitus, spironolactone use, and furosemide use was significantly higher in the SGLT2 + group (all p < 0.05). LVEF was lower (32.9 ± 6.7 vs. 38.7 ± 8.6, p = 0.002), and left ventricular volumes were larger in the SGLT2 + group, while LAFI was significantly reduced (0.12 ± 0.08 vs. 0.18 ± 0.10, p = 0.008). However, there were no significant differences in LAVI or LAEF between groups. Multivariable regression identified E/A ratio, age, and LVEF as independent determinants of LAVI; posterior wall thickness and E/A ratio for LAEF; and E/A ratio, diabetes mellitus, posterior wall thickness, and interventricular septal thickness for LAFI.

SGLT2 inhibitor use was not associated with significant improvement in LA volume or functional parameters in patients with HF and reduced or mildly reduced EF. The prognostic value of LA functions appears to be primarily influenced by diastolic dysfunction and ventricular remodeling rather than SGLT2 inhibitor therapy.