Abstract
BACKGROUND: The left atrial appendage (LAA) is a well-known source of atrial arrhythmia and atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to determine whether LAA exclusion using the LARIAT device would decrease AF burden. METHODS: A total of 50 patients with AF and cardiac implantable electronic devices who underwent successful LAA exclusion were enrolled in this prospective observational study. AF burden before LAA exclusion (baseline) and 3 and 12 months after exclusion was assessed by device interrogation. RESULTS: AF burden at 3-month follow-up (42% ± 34%) was significantly lower compared to baseline (76% ± 33%, P < .0001). The reduction in AF burden was sustained at 12 months (59% ± 26%, P < .001). Subgroup analysis revealed that AF burden at 3-month follow-up was similarly reduced in both paroxysmal AF (n = 19) and nonparoxysmal AF (n = 31). However, there was no reduction in AF burden in patients with paroxysmal AF at 12 months. AF burden in patients with known AF triggers in the LAA (n = 9) was significantly reduced at 3 months (52% ± 35%) and 12 months (42% ± 19%) compared to respective baseline (84 ± 31%, P < .0001). CONCLUSION: LAA exclusion appears to reduce AF burden. The presence of AF triggers in the LAA appears to be the strongest predictor of AF reduction. The study underscores the role of the LAA in arrhythmogenesis for AF and highlights the complementary role of LAA exclusion in restoration of normal sinus rhythm.