Cathepsin Levels and Atrial Fibrillation Risk: Insights From Bidirectional and Multivariable Mendelian Randomization Analyses

This study provides genetic evidence that elevated cathepsin O levels-and conditionally cathepsin B-are causally linked to increased AF risk. These findings highlight the potential role of proteolytic enzymes in AF pathogenesis and suggest novel therapeutic targets. All analyses were conducted in European-ancestry populations; replication in diverse cohorts and mechanistic studies are warranted to validate and extend these insights.