Background: Acute coronary syndrome encompasses unstable angina, non–ST-elevation myocardial infarction, and ST-elevation myocardial infarction. Coronary artery disease stands as the leading cause of death worldwide. The condition is not typically suspected in young individuals, particularly those without a substantial family history. Hyperhomocysteinemia and elevated lipoprotein(a) levels are recognized as significant risk factors and can be integrated into screening tools for early identification and intervention.
 
Case Presentation: A 23-year-old man was diagnosed with an evolved anterior wall myocardial infarction, verified through ECG and echocardiography. Further investigation using coronary angiography revealed a single-vessel disease with the involvement of branch vessels, which was treated successfully via bifurcation stenting. Optical coherence tomography analysis of the lesion indicated a fibrous-atheromatous lesion accompanied by thrombosis. Upon evaluation, high lipoprotein(a) and hyperhomocysteinemia were identified as risk factors contributing to the patient’s condition.
 
Conclusions: Lipoprotein(a) and familial hyperhomocysteinemia should not be exclusively linked to a family history of premature atherosclerotic cardiovascular disease (ASCVD). These factors should be considered important in screening due to their significant impact on ASCVD risk. Furthermore, intracoronary imaging should be employed extensively to gain insights into the pathophysiology of the disease and enhance interventional strategies in these situations. (Iranian Heart Journal 2025; 26(1): 113-121)