Relation of a Filling Defect of Left Atrial Appendage by Contrast Computed Tomography Image With Subsequent Clinical Events in Patients With Atrial Fibrillation Receiving Catheter Ablation Procedures

Abstract

Filling defect (FD) in left atrial appendage (LAA) is commonly observed in contrast computed tomography (CT) among patients with atrial fibrillation (AF), although its prognostic impact has not been well explored. We enrolled 1,019 consecutive patients who underwent AF ablation with baseline contrast CT images. FD in LAA was graded into 3 groups: grade 0 for complete filling (79.7%), grade 1 for incomplete filling (12.6%), and grade 2 for complete FD (7.8%). We evaluated the impact of the FD grade on the long-term clinical outcomes during the mean follow-up of 4.4 ± 2.0 years. Patients with grade 2 FD had higher prevalence of nonparoxysmal AF, higher brain natriuretic peptide level, and larger left atrial volume than those with grade 0 or 1 FD. The 5-year cumulative incidence of recurrent atrial tachyarrhythmias was higher in patients with grade 2 FD than those with grade 0 or 1 FD (74.0% vs 38.8% and 62.1%, log-rank p <0.001). The 5-year cumulative incidence of major adverse cardiovascular events (MACEs), defined as a composite of all-cause death, heart failure hospitalization, and ischemic stroke, was also significantly higher in patients with grade 2 FD (19.4% vs 5.6% and 9.5%, log-rank p <0.001). Follow-up CT images acquired in 87.1% of patients at median interval of 98 days showed significantly decreased FD (grade 1 in 4.5% and grade 2 in 2.1%, p <0.001). The residual grade 2 FD at follow-up was associated with significantly higher risk for subsequent MACEs. In conclusion, among patients with AF receiving catheter ablation, severe FD in LAA in contrast CT was associated with higher incidence of arrhythmia recurrence and MACEs during follow-up.