Association Between Proximal Stent Edge Positioning on Atherosclerotic Plaques Containing Lipid Pools and Postprocedural Myocardial Infarction (from the CLI-POOL Study)

Postprocedural myocardial infarction is an ominous complication of percutaneous coronary intervention (PCI). Despite several patient, lesion, and procedural factors that may affect its occurrence and severity, it is unclear if implanting a stent edge on a coronary lipid pool, as appraised by optical coherence tomography (OCT), adversely affects outcomes. The aim of this study was to assess the association between postprocedural myocardial infarction and the implantation of a stent edge on a lipid pool, as assessed by OCT. A database was screened for patients without ongoing myocardial infarctions; who underwent PCI with stenting for single, native, de novo lesions; without periprocedural side-branch occlusion or compromise; who underwent post-PCI OCT; and had postprocedural myocardial infarctions. These subjects were matched 1:1 with patients with similar features but without postprocedural myocardial infarctions. Plaque characterization with OCT was performed using established criteria. Specifically, lipid pools within stent edges were quantified by computing the number of involved quadrants and the degree of lipid arc on cross-sectional images. A total of 30 patients were included (15 with postprocedural myocardial infarctions and 15 controls without infarctions). Whereas no patient or control subject had lipid pools in correspondence to distal stent edges, landing of proximal stent edges on lipid pools was significantly more frequent in patients than in controls (10 [66%] vs 2 [13%], p = 0.009), Moreover, patients with postprocedural myocardial infarctions had more extensive lipid pools at proximal stent edges than those without postprocedural myocardial infarctions. Accordingly, lipid pool arc at proximal stent edge was significantly associated with peak post-PCI creatine kinase-MB/upper limit of normal ratio (Spearman's p = 0.49, p = 0.006). In conclusion, incomplete stent coverage of coronary lipid pools appears to be associated with an increased risk for postprocedural myocardial infarction in patients who undergo PCI. (C) 2013 Elsevier Inc. All rights reserved. (Am J Cardiol 2013;111:526-531)