To the Editor A recent study investigated the safety and effectiveness of percutaneous left atrial appendage (LAA) ligation with catheter pulmonary vein isolation (PVI) for nonparoxysmal atrial fibrillation (AF). Although the study design and execution were commendable, we have several concerns about its methodology and interpretation. First, the study’s primary outcome measure of freedom from documented atrial arrhythmias at 12 months may not have fully captured the efficacy of percutaneous LAA ligation adjunctive to PVI isolation. The study did not assess LAA electrical isolation, which is important considering the mechanism of action of the intervention. Second, we have questions about the sample size estimation and the 2:1 randomization of patients. The decision to favor a higher ratio for the treatment group was primarily undertaken to accumulate more safety data. However, this skewed randomization may have affected the statistical power and generalizability of the findings, particularly in assessing efficacy outcomes.
