Metformin and Atrial Fibrillation: A Systematic Review of Their Association

Atrial fibrillation (AF) is a common cardiac arrhythmia with a significant impact on patient outcomes and healthcare systems. Given the rising incidence of AF with age and its association with conditions, such as diabetes, there is growing interest in exploring pharmacological interventions that might mitigate AF risk. Metformin, a widely prescribed antihyperglycemic agent for type 2 diabetes mellitus (T2DM), has demonstrated various cardiovascular benefits, including anti-inflammatory and antioxidative properties, leading to speculations about its potential role in AF prevention. This systematic review synthesizes findings from five studies examining the association between metformin use and AF risk in patients with T2DM. The review included a dynamic cohort study, three retrospective cohort studies, and a case report, all sourced from databases, such as PubMed, Embase, and the Cochrane Library. The results are mixed; while some studies suggest that metformin use is linked to a reduced incidence of AF, others report no significant association, particularly in postoperative settings. The largest cohort study highlighted a dose-response relationship, suggesting prolonged metformin use correlates with lower AF risk. Conversely, a case report raised concerns about metformin-induced lactic acidosis potentially triggering AF episodes. The review underscores the heterogeneity in study designs and outcomes, pointing to the need for more robust research to establish causality and clarify underlying mechanisms. Future studies should prioritize prospective designs and explore the pleiotropic effects of metformin on atrial remodeling and electrophysiology to better understand its potential role in AF prevention.