evaluation of underlying coronary stenosis severity in patients with acute mi after thrombus aspiration using export catheter

background: early clinical and retrospective angiographic evaluations indicated that in patients with acute myocardial infarction (mi), vulnerable plaques most often represented a mild luminal stenosis. more recent studies drawing upon prospective angiograms, however, have demonstrated that in majority of patients with acute mi, the underlying stenosis is significant.   methods: twenty-eight patients with acute mi candidated for thrombectomy were enrolled in this study. thrombectomy was performed using export thrombectomy catheters. after the injection of nitroglycerin, the severity of the lesions was determined by two independent operators.   results: between april 2007 and february 2008, 28 patients, comprised of 26 men and 2 women with acute mi, were evaluated. the underlying stenosis severity was ≥50% in 22 (78.6%) patients and <50% in the remaining 6 (20.4%) patients (p-value <0.01). the right coronary artery was the most common vessel involved in the lesions <50%. conclusion: contrary to the general belief of many cardiologists, the majority cases of myocardial infarction occur in consequence of significant stenoses.