Objective To explore the clinical effects and safety of the delayed PCI combined with tirofiban compared with selective PCI in acute myocardial infarction (AMI) patients, so as to perform an earlier PCI for the AMI patients who missed the emergency time window and improve the prognosis.

Methods A total of 80 patients with first AMI within 24 h to 7 days were randomised into two groups, the delayed PCI group (DPG, n=38) and the control group (CG, n=42). In DPG, tirofiban was administered 10 μg/kg within 3 min as a bolus followed by 0.15 μg/kg/min, then transferred to the catherlab at once to perform CAG and PCI, while in CG, the patients received PCI to deal with infarct-related artery 7–10 days after infarction. The clinical information, the haemorrhage events, MACE in hospital were collected. QCA and TMPG was used to analyse the coronary artery situation and the reperfusion of the IRA. The patients information in-hospital and on the 90^th day after PCI were compared.

Result There were no significant differences in clinical characteristics between the two groups. There was a greater percentage of TIMI 1 (p<0.05) flow of IRA, but no significant difference in the percentage of TIMI 2 and TIMI 3, in DPG than that in CG before PCI. The ratio of total occlusion lesion at the time of CAG, as well TIMI 0 flow of IRA after the guide wire first crossing, was significantly lower than that in CG (both p<0.05), while the percentage of TIMI 3 flow after stenting was higher (p<0.05), the CTFC was fewer in DPG (p<0.05), and the percentage of TMPG beyond 2 grade was higher in DPG (p<0.05) than that in CG after stenting. There was no significant difference in LVEDVI, LVESVI, LVEF during in-hospital and in LVEF after 3 months of PCI (p>0.05) between the two groups, while the LVEDVI, LVESVI were lower, LVEF was higher 3 months later in both groups. The platelet aggregation rate in DPG was lower after tirofiban administration. There was no significant difference in haemorrhage events and MACE between two groups.

Conclusions Delayed PCI combined with tirofiban may increase coronary blood flow, improve tissue-level perfusion and preserve the heart function, but did not obviously increase the haemorrhage events compared with selective PCI, which indicated that delayed PCI combined tirofiban may be an effective and safe way in the treatment of AMI.