Echocardiographic parameters of left atrial structure and function in elderly patients with atrial fibrillation, and clinical outcomes at 2 years: the ANAFIE echocardiographic substudy

Background Previous studies have shown an association between echocardiographic parameters of cardiac structure and function and prognosis in patients with atrial fibrillation (AF). However, only limited data are available for elderly patients (age, ≥75 years). Purpose The All Nippon Atrial Fibrillation In the Elderly (ANAFIE) Registry (UMIN000024006) was a prospective, multicenter, observational study which collected real-world data on the clinical status and prognosis of 33,062 Japanese patients aged ≥75 years and with non-valvular AF (NVAF). A prospective substudy of 1,474 patients who underwent transthoracic echocardiography at baseline was conducted to investigate relations between echocardiographic parameters of left atrial structure and function and clinical outcomes at 2 years. Methods Cumulative incidences and adjusted hazard ratios (HRs) of clinical outcomes were calculated using Kaplan–Meier analysis and the Cox proportional-hazards model, respectively. The data were analysed by left atrial volume index (LAVi) category, left atrial emptying fraction (LAEF) category, and direct oral anticoagulant (DOAC) use vs warfarin (WF) use. Cardiovascular (CV) events was a composite of stroke, myocardial infarction (MI), cardiac interventions, heart failure (HF) hospitalization, CV death. Cardiac events was a composite of MI, cardiac intervention, HF hospitalization, and CV death. Results Baseline characteristics were mean age of 80.7 years; male, 59.2%; paroxysmal AF, 45.9%; mean CHA2DS2-VASc score, 4.3; mean HAS-BLED score, 1.9; median LAVi, 48.7 mL/m2; median LAEF, 26.6%; comorbidity or history of HF, 32.2%; oral anticoagulant use, 92.7%; DOAC use, 68.7%; and WF use, 24.0%. Incidences (/100 patient-years) and HRs (95% CIs) for each clinical outcome according to LAVi and LAEF category are summarized in Table. Compared with patients with LAEF >45.0% (n=224), those with LAEF ≤45.0% (n=1,213) were at higher risk of CV events (2.19 [1.13–4.27], p=0.021) and HF hospitalization (2.25 [1.02–4.96], p=0.045). Risk of all-cause death was higher in patients with LAVi >48.0 mL/m2 (n=656) than in those with LAVi ≤48.0 mL/m2 (n=621) (1.69 [1.00–2.83], p=0.048). In the subgroups with LAEF ≤45.0% or LAVi >48.0 mL/m2, patients receiving a DOAC had significantly lower risk of cardiac events, CV events, and HF hospitalization than patients receiving warfarin. Conclusion In elderly Japanese patients with NVAF, those with LAEF ≤45.0% are at higher risk of CV events and HF hospitalization, and those with LAVi >48.0 mL/m2 are at higher risk of all-cause death. Thus, the higher risk differs between patients with LAEF ≤45.0% and those with LAVi >48.0 mL/m2. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Co., Ltd.