AimPatients with metabolic dysfunction‐associated steatotic liver disease (MASLD) are at increased risk of incident cardiovascular disease. However, the clinical characteristics and prognostic importance of MASLD in patients presenting with acute myocardial infarction (AMI) have yet to be examined.MethodsThis study compared the characteristics and outcomes of patients with and without MASLD presenting with AMI at a tertiary centre in Singapore. MASLD was defined as hepatic steatosis, with at least one of five metabolic criteria. Hepatic steatosis was determined using the Hepatic Steatosis Index. Propensity score matching was performed to adjust for age and sex. The Kaplan‐Meier curve was constructed for long‐term all‐cause mortality. Cox regression analysis was used to investigate independent predictors of long‐term all‐cause mortality.ResultsIn this study of 4446 patients with AMI, 2223 patients with MASLD were matched with patients without MASLD using propensity scores. The mean follow‐up duration was 3.4 ± 2.4 years. The MASLD group had higher rates of obesity, diabetes and chronic kidney disease than their counterparts. Patients with MASLD had early excess all‐cause mortality (6.8% vs. 3.6%, p < .001) at 30 days, with unfavourable mortality rates sustained in the long‐term (18.3% vs. 14.5%, p = .001) compared with those without MASLD. After adjustment, MASLD remained independently associated with higher long‐term all‐cause mortality (hazard ratio 1.330, 95% confidence interval 1.106‐1.598, p = .002).ConclusionMASLD embodies a higher burden of metabolic dysfunction and is an independent predictor of long‐term mortality in the AMI population. Its early identification may be beneficial for risk stratification and provide therapeutic targets for secondary preventive strategies in AMI.