Video abstractPoint your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use:https://youtu.be/LUESRF3ZdccBackground: Risk stratification models with incorporation of biochemical markers have received attention recently. In acute myocardial infarction (AMI) one such marker is lipoprotein(a) (Lp(a)). Lp(a) has prothrombotic and proinflammatory properties. High levels of Lp(a) probably contribute to the additional adverse effects in AMI, as it enhances the damaging effect of acute thrombosis. This study aimed to evaluate serum Lp(a) as a predictor of major adverse cardiovascular events (MACE) in hospitalized-acute myocardial infarction patients. Methods: A prospective cohort study was conducted at Sanglah Hospital, Denpasar, during June-August 2018, among 66 people by consecutive sampling. Samples that met the inclusion and exclusion criteria were examined for serum Lp(a) at the time of admission and the occurrence of MACE during hospitalization was observed. Data regarding serum Lp(a), demography, smoking history, dyslipidemia, hypertension, diabetes mellitus, and MACE were collected. Log rank test and Cox proportional hazards regression were conducted with SPSS version 20 for Windows. Results: During observation, MACE occurred in 25 (38%) patients, including cardiogenic shock in 7 (10.6%) patients, heart failure in 20 (30.3%) patients, cardiovascular death in 5 (7, 6%) patients, malignant arrhythmias in 5 (7.6%) patients, and postinfarction angina in 5 (7.6%) patients. After the Log rank test, a significant difference in survival was observed (p = 0.001) between groups of high Lp(a) (survival rate of 60.6 hours; 95% CI 43.3-77.9) and low Lp(a) (average survival of 104.3 hours, 95% CI 91.4-117.2). The hazard ratio of high Lp(a) against MACE was 4.63 (p=0.002), and it increased to 4.69 in multivariate analysis with Cox proportional hazards regression test (p=0.003). Conclusion: The high level of Lp(a) in AMI patients was a risk factor for the occurrence of MACE during hospitalization. Patients with high Lp(a) also had worse survival compared to patients with low Lp(a).