Background: The relationship between the characteristics of tissue protrusion detected by using optical coherence tomography (OCT) and the findings of coronary angioscopy (CAS) immediately after stent implantation were evaluated.Methods and Results:A total of 186 patients (192 stents) underwent OCT before and after stenting and were observed by using CAS immediately after stenting and at the chronic phase. Patients were assigned to irregular protrusion, smooth protrusion, and disrupted fibrous tissue protrusion groups according to OCT findings. Serum high-sensitivity C-reactive protein (hs-CRP) levels were measured before and after stent implantation. The grade of yellow color (YC) and neointimal coverage (NC), and incidence of thrombus in the stented segment were evaluated by using CAS. After stent implantation, maximum YC grade (smooth, 0.64±0.80; disrupted fibrous tissue, 0.50±0.77; irregular, 1.50±1.09; P<0.0001), a prevalence of Max-YC grade of 2 or 3 (smooth, 17%; disrupted fibrous tissue, 17%; irregular, 50%; P<0.0001) and thrombus (smooth, 15%; disrupted fibrous tissue, 10%; irregular, 69%; P=0.0005), and elevated hs-CRP levels (smooth, 0.22±0.89; disrupted fibrous tissue, -0.05±0.29; irregular, 0.75±1.41; P=0.023) were significantly higher in irregular protrusion than in the other 2 groups. In the chronic phase, maximum- and minimum-NC grade and heterogeneity index, and thrombus did not differ significantly among the 3 groups.
Conclusions: Irregular protrusion was associated with atherosclerotic yellow plaque, incidence of thrombus, and vascular inflammation. The angioscopic findings in the chronic phase may endorse the clinical efficacy of second- and third-drug eluting stents, regardless of the tissue protrusion type.
Keywords: Coronary angioscopy; Optical coherence tomography; Tissue protrusion.