Obesity and left atrial function in heart failure with preserved ejection fraction: OLA-HF registry.

BACKGROUND: Obesity is associated with heart failure with preserved ejection fraction (HFpEF), but diagnosis remains challenging due to low natriuretic peptide levels and the limitations of conventional echocardiographic parameters. Left atrial function may provide additional information on hemodynamic burden. OBJECTIVES: Assess the associations of Global Peak Atrial Longitudinal Strain (PALS) with NT-proBNP levels, and 6-min walk test in obese patients with HFpEF. METHODS: Single-center, retrospective study including 118 obese patients (BMI ≥30 kg/m2) with HFpEF. Patients underwent clinical evaluation, laboratory analysis, transthoracic echocardiography with speckle-tracking analysis, and 6MWT. A Multivariate linear regression adjusted for age, sex, BMI, eGFR, atrial fibrillation, and mean E/e' was done. RESULTS: Study population's median age was 77 [68-82] years, 59% were male, median Global PALS was 23.0 [17.3-30.8]%, and E/e' ratio 10 [8-13]. Global PALS was inversely associated with ln(NT-proBNP) in univariate analysis (β = -0.096 ± 0.011; p < 0.001) and remained independently associated after adjustment (β = -0.045; 95% CI -0.070 to -0.019; p < 0.001). Global PALS was not associated with functional capacity (6MWT) (p = 0.150). Atrial stiffness was independently associated with ln(NT-proBNP) (β = 0.27; p = 0.014) and 6MWT (β = -9.3; p = 0.046). No significant associations were observed between atrial function and clinical outcomes. CONCLUSIONS: In obese HFpEF patients, LA strain is associated with NT-proBNP levels, while atrial stiffness is associated with NT-proBNP and functional capacity. These parameters provide complementary information on hemodynamic burden and clinical status.