Abstract 12536: Occurrence of New-Onset Atrial Fibrillation in Patients After Left Atrial Appendage Closure

Introduction: Left atrial appendage closure (LAAC) has evolved as a non-pharmacological alternative for stroke prevention in patients with Atrial fibrillation (AF). The occurrence of post-operative AF is well described after cardiac and percutaneous procedures. But, there is limited understanding of the possibility of new-onset AF as a result of LAAC. Aims: To investigate the incidence of, and factors associated with, AF after LAAC. Methods: We conducted a retrospective analysis of 121 patients with i) paroxysmal AF, 2) had undergone LAAC, and 3) had an implantable electronic devices (CIEDs): pacemaker, defibrillator or implantable loop recorder. Patients with persistent AF and those presenting in AF on the day of LAAC were excluded. Data were collected on baseline characteristics, Colchicine use, antiarrhythmic drugs and prior history of AF ablation. Remote transmissions and device interrogations were analyzed to ascertain new-onset AF during the 6 months follow up period after LAAC. Univariate and multivariable analyses were performed to analyze factors associated with the occurrence of AF after LAAC. Results: Of the total 121 patients, 39 (32.2%) developed AF during the 6 month follow up period after LAAC. On univariate analysis, a lower CHA2DS2-Vasc score was associated with a lower incidence of AF post LAAC (OR 0.74, 95% CI 0.55-0.98, p = 0.04). On multivariable analysis, including variables of age, gender, CHA2DS2-Vasc score, use of Colchicine and history of AF Ablation, we observed a statistical trend towards the protective effect of prior AF ablation on occurrence of AF after LAAC (adjusted OR 0.32, 95% CI 0.10-1.05, p =0.06). There was also a statistical trend towards the protective effect of Colchicine on occurrence of AF after LAAC (adjusted OR 0.15, 95% CI 0.02-1.29, p =0.08). Conclusions: In our study of paroxysmal AF patients undergoing LAAC, who presented in sinus rhythm on the day of the procedure, the incidence of CIED detected post-procedural AF was 32.2%. We observed statistical trends towards protective effects of prior AF Ablation and use of Colchicine during the peri-LAAC period on occurrence of AF after LAAC.