Feasibility and Impact of Left Atrial Appendage Closure in Patients with Cardiac Implantable Electronic Devices: Insights from a Prospective Registry

<b>Background</b>-Percutaneous left atrial appendage (LAA) closure (LAAC) offers a valid alternative to oral anticoagulation in patients with atrial fibrillation (AF) at high risk of bleeding. However, its impact on AF burden and device function in patients with cardiac implantable electronic devices (CIEDs) remains largely unexplored. <b>Methods</b>-From our prospective LAAC registry (clinicaltrial.gov-NCT04628078), which includes all consecutive LAAC procedures performed at our institution, we identified patients with a CIED and retrospectively analyzed procedural and follow-up data. The primary endpoint was defined as a composite of death, TIA/stroke, systemic or pulmonary embolism and major bleeding (BARC 3-5) within 7 days of the procedure. The secondary endpoint was CIED lead dislodgement. Additionally, AF burden was compared before and after LAAC. <b>Results</b>-Of the 586 LAAC procedures performed between August 2015 and January 2023, 36 patients (6%) had a CIED. The median CHA₂DS₂-VASC and HAS-BLED scores were 4.0 and 3.0, respectively. The primary endpoint occurred in one (3%) patient, and no patient experienced CIED lead dislodgement. AF burden data before and after LAAC were available in 20 patients. The mean AF burden increased from 6% to 31% following LAAC (<i>p</i> = 0.064). <b>Conclusions</b>-A CIED was present in 6% of LAAC procedures, and LAAC appears feasible and safe in this patient population. Larger, prospective studies are warranted to further evaluate the impact of LAAC on AF burden.