Study Cohort
We conducted a single-center, retrospective cohort study comprising patients derived from an IRB-approved, prospectively populated clinical database of AF ablation patients. All patients underwent either first or repeat AF ablation between February 2019 to March 2021 at the Johns Hopkins Hospital. All patients underwent a preprocedural cardiac CT scan or cardiac magnet resonance imaging (MRI) to assess the left atrium (LA) and pulmonary vein (PV) anatomy in detail. The total patient cohort was divided into pre-COVID and post-COVID cohorts based on the Spring 2020 peak of the COVID-19 pandemic (when ablation procedures were temporarily halted in our hospital) and pre-procedural imaging for LAA thrombus evaluation. The pre-COVID cohort consisted of ablations performed between February 2019 to January 2020, and the post-COVID cohort included ablations performed between April 2020 to March 2021. All patients signed written informed consent at the time of the procedure. Demographics, clinical history, imaging data, procedural data, and complications were recorded for each procedure.