Metabolic dysfunction-associated fatty liver disease phenotypes and 1-year cardiovascular outcomes in patients with obstructive coronary artery disease: a prospective cohort study.

Background: The prognostic significance of lean metabolic dysfunction-associated fatty liver disease (MAFLD) in patients with obstructive coronary artery disease remains uncertain. We evaluated 1-year cardiovascular outcomes in lean versus non-lean MAFLD. Methods: This prospective observational cohort study included 193 adults with MAFLD and coronary computed tomography angiography (CCTA)-defined obstructive coronary artery disease at Thong Nhat Hospital, Vietnam. Lean MAFLD was defined as a body mass index <23 kg/m² and non-lean MAFLD as a body mass index ≥23 kg/m². The primary outcome was the first expanded major adverse cardiovascular event (eMACE) within 365 days, including ischemia-driven coronary revascularization. Planned first percutaneous coronary intervention (PCI) after baseline CCTA was included. Kaplan-Meier and Cox proportional hazards analyses were performed. Results: During follow-up, 115 patients (59.6%) experienced eMACE. The eMACE rate was higher in lean than in non-lean MAFLD (86.2% vs 54.9%, P=0.002). Among these cases, recorded components were revascularization (108), myocardial infarction (13), unstable angina (26), acute heart failure (1), stroke (0), and cardiovascular death (0); components overlapped. These counts do not establish first-event attribution. Lean MAFLD remained associated with eMACE after adjustment for age, sex, and multivessel coronary artery disease (adjusted HR 2.07, 95% CI 1.32-3.26, P=0.002). Conclusions: Among patients with MAFLD and obstructive coronary artery disease, lean MAFLD was associated with a higher 1-year hazard of eMACE than non-lean MAFLD, after adjustment for age, sex, and multivessel coronary disease. The small lean group and inclusion of planned revascularization limit extrapolation to non-revascularization events, confirmation in larger cohorts is needed.