Abstract: Abstract: Objective To investigate and compare the curative effect between delayed percutaneous coronary intervention (PCI) for patients with acute myocardial infarction presenting 12-24 hours from symptom onset and medical therapy on acute myocardial infarction patients presenting with ST-segment elevation (STEMI). Methods Using a prospective, open, parallel, controlled research approach, 186 patients with STEMI were divided into delayed PCI group (n＝ 89), which received PCI within 12-24 hours after STEMI and medical therapy group (n=97), which received medical therapy after STEMI. All patients were followed up 1-6 months with average follow-up (5.6±1.4) months. Data of hospitalization period, the cardiac structures detected by echocardiography such as left atrial diameter (LAD), left ventricular diastolic diameter (LVDd), left ventricular ejection fraction LVEF, left ventricular fractional shortening (LVFS), composite end point events and major adverse cardiac events (MACE) were compared between the two groups. Results Compared with medical therapy group, the hospitalization cycle was significantly shorter in delayed PCI group. Data of the LAD and LVDd were significantly decreased, but LVEF and LVFS were increased in delayed PCI group compared with those of medical therapy group at 30 d and 6-month follow-up. The incidence of MACE and composite end point events were significantly less in delayed PCI group than those of medical therapy group (P＜0.05). Conclusion Delayed PCI treatment can decrease the time of hospital stay and decrease the incidence rates of MACE and composite end point events, and improve left ventricular function and prognosis of patients.

Key words: myocardial infarction, angioplasty, transluminal, percutaneous coronary, ventricular function, left, drug therapy, delayed PCI, medical therapy