Measures of left atrial function and risk of incident atrial fibrillation in patients with heart failure with reduced ejection fraction

AIMS: Measures of left atrial (LA) function have demonstrated prognostic value in relation to incident atrial fibrillation. This study aimed to investigate the relationship between measures of LA function and the risk of incident atrial fibrillation (AF) in outpatients with HFrEF. METHODS AND RESULTS: Subjects were retrospectively included from a HF clinic and followed using the Danish National Patient Registry. Measures included LA emptying fraction (LAEF), peak atrial longitudinal strain (PALS), and peak atrial contractile strain (PACS). Prognostic value was assessed with Cox proportional hazards regressions. Effect modification by sex, valve disease, and LA enlargement was assessed using interaction terms. The final study population consisted of 452 subjects (mean age 65.5 ± 11.8 years, male sex 70.1%) free from AF at baseline. During a median follow-up of 9.4 years IQR: 5.2, 12.7, 118 (26.1%) developed AF. These subjects exhibited higher LAVi, while LAEF, PALS, and PACS were all significantly lower. All three measures of LA function were significantly associated with incident AF in univariable and adjusted Cox regression analysis (Adjusted analysis: LAEF: HR 1.03 per 1% decrease, 95% CI: 1.02-1.04, P = 0.009, PALS: HR 1.06 per 1% decrease, 95% CI: 1.04-1.09, P = 0.037, PACS: HR 1.07 per 1% decrease, 95% CI: 1.03-1.10, P = 0.021). The prognostic value of LAEF was modified by sex and valve disease (P for interaction = 0.007 and 0.041, respectively), while the value of PACS was modified by valve disease (P for interaction = 0.011). CONCLUSION: Impaired PALS, LAEF, and PACS were all associated with an increased risk of incident AF in outpatients with HFrEF.