Abstract: AIM: To follow up patients with acute ST-segment elevated myocardial infarction (ASTEMI) by different reperfusion time 12 months after discharge from the hospital and to investigate the influence of different reperfusion time on ASTEMI endpoint events and prognosis of the heart function. METHODS: Two hundred and thirty-eight ASTEMI cases were divided into 3 groups by percutaneous coronary intervention (PCI) treatment, non-PCI treatment and times of reperfusion: emergency PCI, within 12 hours after chest pain, 89 cases; delayed PCI, over 24 hours after chest pain, 86 cases; and conservative treatment, over 24 hours after chest pain, 63 cases. Clinical data of the three groups were registered, follow up was conducted in all the patients by telephone 12 months after discharge from the hospital, and an echocardiography examination was arranged for each case. RESULTS: Significant difference was found in the primary endpoint event (cardiac death) 12 months after the discharge (P<0.05) and in secondary endpoint events (re-admission rate of AMI and heart failure) among the three groups (P<0.05). Significant difference was observed in LVEF and LVDd between emergency PCI group and delayed PCI group 12 months (P<0.05) and between emergency PCI group and conservative group (P<0.05). There was significant difference in 6-minute-walk test among the three groups (P<0.05). CONCLUSION: To reduce the endpoint events and enhance the heart function, emergency PCI is superior to delayed PCI and delayed PCI is better than conservative treatment.