Impact of different treatment times on prognosis of primary percutaneous coronary intervention for acute myocardial infarction

Objective To evaluate the impact of different treatment times on prognosis of primary percutaneous coronary intervention(PCI)for acute ST-elevation myocardial infarction(STEMI). Methods A total of 153 STEMI patients were enrolled from January 2004 to September 2006. According to the Symptom-onset-to-ballon time(SBT), the patients were divided into two groups. Group A consisted of 112 patients with SBT ≤ 6 hours, and Group B included 41 with SBT between 6 and 12 hours. The number of ECG leads with ST-elevation resolusion(STR) 70% after PCI was determined, and changes in left ventricular ejection fraction and incidence of major adverse cardac events(MACE)during one-year follow-up were also recorded. Results Clinical and angiographic characteristics were similar in the two groups. The number of ECG leads with STR 70% after PCI was significantly greater in Group A than that in Group B(P 0.05). During follow-up, left ventricular ejection fraction was higher, and the incidence of MACE was lower in Group A than those in Group B(all P 0.05). Conclusions Direct PCI ≤ 6 h after onset of symptoms results in significant improvement in myocardial reperfusion, better recovery of left ventricular function, and decrease in total MACE rate during follow-up.