Steatotic liver disease phenotypes and stroke risk in patients with atrial fibrillation: A nationwide population-based cohort study

BACKGROUND The updated nomenclature of steatotic liver disease (SLD) recognizes distinct phenotypes, including Metabolic dysfunction-associated steatotic liver disease (MASLD), MASLD with increased alcohol intake (MetALD), and alcohol-related liver disease (ALD). Although cardiovascular risk may differ across SLD phenotypes, their association with stroke risk in patients with atrial fibrillation (AF) remains unclear. OBJECTIVE This study aimed to investigate the association between SLD phenotypes and ischemic stroke risk in AF patients. METHODS AF patients diagnosed between 2010 and 2018 were identified from the Korean health insurance database. According to SLD phenotype, patients were categorized into No-SLD, MASLD, MetALD, and ALD. The primary outcome was ischemic stroke. Subgroup analyses were conducted by CHA2DS2-VA score. RESULTS Among 196,242 patients (No-SLD: 101,308; MASLD: 77,715; MetALD: 8,678; ALD: 8,541), median follow-up was 5.9 years. Compared with No-SLD, MASLD was not associated with stroke risk (adjusted hazard ratio and 95% confidence interval; 1.00, 0.97-1.04), whereas MetALD and ALD were associated with higher risk (1.09, 1.00-1.18 and 1.16, 1.08-1.26, respectively). In exploratory subgroup analyses, the higher risk associated with alcohol-related phenotypes appeared more apparent at lower CHA2DS2-VA scores; however, the 6-year absolute risk differences were approximately 1% or less, and these findings are regarded as hypothesis-generating. CONCLUSION In patients with AF, stroke risk was significantly higher in the alcohol-related SLD phenotypes, MetALD and ALD, whereas MASLD was not associated with stroke risk. These findings are consistent with the current recommendations for comprehensive risk-factor management in AF, with particular attention to alcohol intake in patients with alcohol-related SLD phenotypes.