A total of 27 patients who underwent successful IVUS-guided percutaneous coronary intervention (PCI) for severe coronary stenosis were retrospectively selected and enrolled from our IVUS database. Inclusion criteria were lesions with chronic total occlusion (CTO) or severely stenotic lesions (%diameter stenosis >90% and delayed distal flow) with angiographic follow-up at 9 months. Exclusion criteria were culprit lesions for acute myocardial infarction, lesions without final IVUS imaging of the distal reference segments and presence of target lesion restenosis or re-occlusion at follow-up. All patients gave written informed consent.
Angiography and Interventional ProceduresAfter intravenous or intraarterial bolus injection of heparin (5,000-10,000 units), coronary angiography (CAG) and the PCI were performed by standard femoral or radial approach oronary arterial segments distal to the severely stenotic or occluded lesion usually shrink as a result of chronically decreased coronary flow. Although differentiation of residual organic stenosis and vessel shrinkage that has the potential to reverse 1 without additional intervention is clinically important in the catheterization laboratory, no specific angiographic, intravascular ultrasonographic or optical coherence tomographic 2-4 findings have been shown.Recent pathological studies have suggested that vessel spasm or shrinkage is accompanied by folding of the internal elastic membrane (IEM). 5,6 Intravascular ultrasound (IVUS) may visualize the folding of the IEM as a high-echoic band and thus could detect chronically shrunken vessels that have potential to enlarge late after revascularization.We hypothesized that a novel IVUS finding, a peri-medial high-echoic band (PHB), would predict chronic vessel enlargement of the distal coronary segments after intervention of the severely stenotic proximal target lesion.
