Anatomical and electrical remodeling with incomplete left atrial appendage ligation: Results from the LAALA-AF registry

Background The anatomical, electrical and clinical impact of incomplete Lariat left atrial appendage ligation remains unclear. Methods We studied LAA anatomy pre-and post-ligation using contrast enhanced- computed tomography (CT) scans in 91 patients with atrial fibrillation (AF) who subsequently underwent catheter ablation (CA). Results Eleven patients had an incomplete exclusion (12%) with a central leak ranging from 1–5 mm. Despite incomplete ligation; the LAA volume were reduced by 67% post-procedurally when compared to pre-procedure. In seven patients with a leak between 1–3 mm, there was a 77% reduction in LAA volume beyond the ligation site suggestive of remodeling of the LAA. In 4 patients with larger (4-5 mm) leak the LAA remnants (LAARs) were slightly larger than those with smaller leaks on follow-up CT scan. Three out of the 4 demonstrated LAA electrical activity during CA and underwent isolation of the LAA ostium. Follow-up imaging showed 2 of these LAARs completely sealed with no communication with the left atrium. There was no significant difference in the AF recurrence rates between the patients who had a leak versus those with complete ligation [4 /11 (36%) vs. 22/80 (27%); p = 0.6]. Oral anticoagulation was discontinued in all patients with small leaks and 2 patients with large leaks that sealed completely upon follow-up imaging. There were no strokes or TIAs at 12 months. Conclusion Despite incomplete LAA ligation by Lariat device there is significant anatomical and electrical remodeling that resulted in reduction in LAA size, volume and electrical activity. This article is protected by copyright. All rights reserved