Prospective, multicenter study of thrombectomy in patients with acute myocardial infarction: the X-Tract AMI registry.

BACKGROUND: Thrombus and soft, friable atheromatous plaque are present in the majority of patients with acute myocardial infarction (AMI), and may result in distal embolization and no reflow during primary angioplasty. Thrombectomy prior to intervention may decrease thromboembolic complications and improve outcomes.

METHODS: The X-TRACT AMI registry was a prospective, multicenter study evaluating the safety and feasibility of the X-Sizer thrombectomy system prior to primary angioplasty in native coronary arteries and saphenous vein grafts (SVGs) in patients presenting within 24 hours AMI onset.

RESULTS: A total of 216 patients (220 target lesions) with AMI were enrolled at 28 U.S. sites, with approximately 90% of lesions in native coronary arteries and 10% in SVGs. Preprocedural TIMI 0/1 flow was present in 56% of patients, with thrombus in 76%. Glycoprotein IIb/IIIa inhibitors were used in 86% of patients, and bare metal stents were implanted in 94% (mean stent length 26 mm). TIMI-3 flow was present in 27% of patients at baseline, in 81% after thrombectomy, and in 92% following PCI. Normal myocardial blush grade 3 was present in 6% of patients at baseline, and in 52% postprocedure. At 30 and 360 days, 93.1% and 80.8% of patients were free from major cardiovascular events.

CONCLUSION: In this broad multicenter experience, use of the X-Sizer device prior to stent implantation in thrombus containing native coronary arteries and diseased SVGs was feasible and associated with high rates of normalized postprocedural epicardial blood flow and myocardial blush, warranting further study as an adjunct during primary angioplasty.