Abstract: AIM:To investigate the effects of percutaneous coronary intervention (PCI) on the level of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the heart function in patients with acute myocardial infarction (AMI). METHODS: One hundred and twenty-eight patients with AMI were divided into group A of primary PCI (n=46), group B of primary and selective PCI (n=48) and group C of conventional treatment (n=34). Plasma NT-proBNP was measured by electrochemiluminescence in these patients immediately, 24 h, 5 days, 11 days, 45 days and 6 months after admission. Patients underwent ultrasound electrocardiogram examination at the 12th-15th day, 45th day and 6th month. RESULTS: NT-proBNP levels after PCI in group A and group B were significantly lower and heart function was better than those in group C (P<0.05). NT-proBNP levels of group B were lower than those in group A at the 45th day and 6th month (P<0.05). The results of ultrasound electrocardiogram at the 45th day and 6th month showed a significant difference in left ventricular end-diastolic diameter (LVDd), left ventricular end systolic volume (LVESV), left ventricular end diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) between group A and group B (P<0.05), whereas no significant difference was seen at the 12th -15th day. CONCLUSION: NT-proBNP level in patients with AMI declines after PCI and can be used as a predictor of cardiac function and ventricular remodeling. Subsequent elective PCI treatment may further reduce the NT-proBNP level and improve heart function.