Abstract
BACKGROUND: The recent reclassification of steatotic liver disease into metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated alcohol-related liver disease has highlighted their potential cardiovascular implications. This study aimed to investigate the impact of MASLD and metabolic dysfunction-associated alcohol-related liver disease on the risk of newly diagnosed atrial fibrillation (AF). METHODS: Data from 362 285 participants who underwent a health screening in 2009 to 2010, sourced from the Korean National Health Insurance database, were identified, and we retrospectively analyzed their data through 2019. Excluding those with other liver diseases and heavy alcoholics, 206 455 participants with a fatty liver index were included. The primary outcome was newly diagnosed AF; associated conditions, such as ischemic stroke and heart failure, were also investigated. Participants were classified into 4 groups based on their steatotic liver disease status and alcohol consumption levels. RESULTS: Over a median follow-up of 9.6 years, 5335 participants were newly diagnosed with AF (2.74 per 1000 person-years). The risk of AF was significantly higher in patients with MASLD who did not consume alcohol (adjusted hazard ratio [aHR], 1.32 [95% CI, 1.23-1.41]; P<0.001) and in those with MASLD with alcohol or metabolic dysfunction-associated steatotic liver disease with increased alcohol intake (aHR, 1.48 [95% CI, 1.36-1.61]; P<0.001). Compared with all other alcohol consumers, regardless of steatotic liver disease status, nondrinking patients with MASLD had a significantly higher risk of AF (aHR, 1.11 [95% CI, 1.02-1.20]; P=0.011). CONCLUSIONS: MASLD is associated with incident AF. These findings suggest that metabolic dysfunction plays a more significant role in AF occurrence than the direct toxic effects of alcohol.