Effectiveness of thrombectomy before stent implantation in acute myocardial infarction.

Percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) may cause distal embolization, with deterioration of distal flow and further extension of the infarct. The purpose of the present study was to evaluate the effectiveness of pretreatment by thrombectomy on myocardial salvage after stent implantation in patients with AMI. From January 2000 to July 2002, 209 consecutive patients with AMI successfully underwent emergency stent implantation. They were divided into 2 groups: those treated in the year before the introduction of the thrombectomy device (Group A; n=109), and those treated the year after introduction of the device (Group B; n=100). Follow-up quantitative coronary angiography (QCA) and left ventriculography were carried out 6 months after PCI. Microvascular circulation after revascularization was assessed by Thrombolysis in myocardial infarction (TIMI) flow grade analysis, the maximum creatine kinase concentration was recorded, and the follow-up left ventricular ejection fraction and ST segment score were assessed on the 12-lead electrocardiography just before revascularization and on return to the coronary care unit. The QCA data, rate of restenosis (% restenosis) and rate of target lesion revascularization were also compared between the 2 groups. The results demonstrated that the introduction of thrombectomy had increased the number of patients who displayed blush-3 after primary angioplasty, which suggests that thrombectomy before stent implantation has the potential to minimize myocardial ischemic insult, presumably by protecting the coronary microvasculature.