Association of left atrial enlargement with heart failure events in non-valvular atrial fibrillation patients with preserved left ventricular ejection fraction

Atrial fibrillation (AF) increases the risk of heart failure (HF); however, little is known regarding the risk stratification for incident HF in AF patients, especially with preserved left ventricular ejection fraction (LVEF). The Fushimi AF Registry is a community-based prospective survey of AF patients. From the registry, 3,002 non-valvular AF patients with preserved LVEF and with the data of antero-posterior left atrial diameter (LAD) at enrollment were investigated. Patients were stratified by LAD (<40 mm, 40-44 mm, 45-49 mm, and ≥50 mm) with backgrounds and HF hospitalization incidences compared between groups. Of 3,002 patients (mean age: 73.5 ± 10.7 years, women: 1,226 [41%], paroxysmal AF: 1,579 [53%], and mean CHA2DS2-VASc score: 3.3 ± 1.7), the mean LAD was 43 ± 8 mm. Patients with larger LAD were older and less often paroxysmal AF, with a higher CHA2DS2-VASc score (all P < 0.001). HF hospitalization occurred in 412 patients during the median follow-up period of 6.0 years. Larger LAD was independently associated with a higher HF hospitalization risk (LAD ≥50 mm; hazard ratio [HR]: 2.36, 95% confidence interval [CI]: 1.75-3.18, LAD 45-49 mm; HR: 1.84, 95%CI: 1.37-2.46 and LAD 40-44 mm: HR: 1.34, 95%CI: 1.01-1.78, compared with LAD <40 mm) after adjustment by age, sex, AF type, and CHA2DS2-VASc score. These results were also consistent across major subgroups, showing no significant interaction. LAD is significantly associated with the risk of incident HF in AF patients with preserved LVEF, suggesting the utility of LAD regarding HF risk stratification for these patients.