Background: Conventional echocardiographic improvements after sodium–glucose cotransporter-2 (SGLT2) inhibitor therapy have been reported in heart failure with preserved ejection fraction (HFpEF), but data on novel composite indices of atrial mechanics, particularly the left atrial (LA) stiffness index and the left atrioventricular coupling index (LACI), remain poorly characterized. The authors evaluated early changes in conventional diastolic parameters and atrial mechanics following initiation of SGLT2 inhibitor therapy.

Methods: In this prospective, single-center observational cohort study, patients with HFpEF in sinus rhythm who were naive to SGLT2 inhibitors received empagliflozin or dapagliflozin. Clinical assessment, laboratory testing, and comprehensive echocardiography were performed at baseline and after 3 months. Echocardiographic evaluation included
LA reservoir and pump strain, the LA stiffness index (E/e′/LA reservoir strain), and LACI (minimum LA volume/LV end-diastolic volume ×100).

Results: Fifty patients completed follow-up (70% women; mean age, 63.9 ± 8.1 years). New York Health Association functional class improved and N-terminal pro–brain natriuretic peptide levels decreased significantly (347 [134.8-524.8] vs. 257 [161.3-427.5] pg/mL; P = .007). Left atrial volume index and E/e′ decreased significantly (34.6 ± 5.5 to 32.6 ± 5.7 mL/m2 and 12.1 ± 3.2 to 9.8 ± 2.8, respectively; both P < .001). Left atrial reservoir and pump strain increased, whereas the LA stiffness index and LACI decreased significantly
(all P < .001).

Conclusions: In this prospective observational cohort of patients with HFpEF, initiation of SGLT2 inhibitor therapy was associated with early changes in conventional diastolic parameters and LA mechanics. Composite atrial indices, particularly the LA stiffness index and LACI, changed in parallel with established clinical and echocardiographic markers, suggesting that they may provide complementary information for monitoring early atrial remodeling during SGLT2 inhibitor therapy.