Associations between MASLD, atrial fibrillation, cardiovascular events, mortality and aspirin use in older adults.

The impact of metabolic dysfunction-associated steatotic liver disease (MASLD), the preferred nomenclature for NAFLD, on cardiovascular health and mortality among older adults is uncertain. As such, we aimed to identify whether MASLD increases the risk of Major Adverse Cardiovascular Events (MACE) (a composite of fatal coronary heart disease [excluding heart failure], nonfatal myocardial infarction, or fatal or nonfatal ischemic stroke), Atrial Fibrillation (AF), or all-cause mortality in older adults, and whether aspirin attenuates these risks in individuals with MASLD. This is a non-prespecified post-hoc analysis of the ASPREE (ASPirin in Reducing Events in the Elderly) randomized trial. Participants were community dwelling well adults aged ≥ 70 years without a history of atherosclerotic cardiovascular disease or AF. Fatty Liver Index (FLI) was used to identify MASLD at baseline. FLI is a composite of anthropometric and biochemical markers used in epidemiologic studies to rule in and rule out hepatic steatosis. MACE and cause of death were adjudicated by clinical experts; AF was assessed by previously defined algorithm in ASPREE. 9,097 participants were stratified into groups according to FLI. In univariate analysis, prevalent MASLD (FLI ≥ 60 with evidence of metabolic dysfunction; n = 2,998 [33.0%]) was associated with an increased risk of MACE (HR 1.47 [95% CI 1.22-1.78]) and AF (HR 1.50 [95% CI 1.19-1.88] but not all-cause mortality (HR 1.04 [95% CI 0.91-1.19]). After adjusting for cardiovascular disease risk factors, only the association between MASLD and AF remained significant (HR 1.46 [95% CI 1.11-1.93]). Aspirin did not reduce the risk of MACE, death, or AF in the MASLD group. MASLD was associated with an increased hazard of incident AF, but not of MACE or all-cause mortality, in community dwelling older adults. Primary prevention with aspirin does not ameliorate these risks in older adults with MASLD.