Relationship Between Coronary Artery Wall Tissue Protrusion And Clinical Events After Coronary Stenting By Optical Coherence Tomography

Objective:In this study,optical coherence tomography(OCT)was used to observe the newly defined tissue protrusion characteristics of patients with clinical events after percutaneous coronary intervention(PCI),which provided new clues and breakthroughs for exploring the relationship between tissue protrusion and clinical events.Method:A retrospective analysis was performed on 198 patients who underwent PCI for coronary heart disease in Sun Yat-sen Memorial Hospital of Sun Yat-sen University from January 2014 to August 2017.These patients underwent preoperative and postoperative assessment with OCT during PCI procedure.A total of 168 cases were successfully followed up,including 95 cases of stable coronary heart disease and 73cases of acute coronary syndrome.The average time from surgery to follow-up was 30.23±3.05 months.The differences in clinical baseline data,OCT-detected target lesion plaques and stent histological characteristics before and after PCI between the two groups were compared according to the occurrence of target lesion failure(Target lesion reconstruction driven by composite cardiogenic death,target vessel myocardial infarction,coronary artery bypass grafting,and clinical conditions).The occurrence of different features of tissue protrusion(A new definition of intrastructural tissue protrusion referred to the tissue of the vessel wall protruding through the stent structure,and the tissue prolapse was located above the stent trabecular.)in the two groups was compared.On the other hand,the histomorphological features of tissue protrusion under the new definition were analyzed.The continuity data was tested for normality.The data satisfied the normal distribution.The mean±standard deviation was used to represent the concentrated trend and discrete trend of the data distribution.The t-test was used for comparison between groups.The median(quartile)was used for non-normal distribution data.The number of spaces)indicates the distribution characteristics of the data,and the comparison between groups used the rank sum test(Wilcox test).The percentage of classified data application(%)indicated the distribution characteristics of the data,and the comparison between groups was?~2.All statistical analyses were performed in SPSS 18.0,and both were tested bilaterally(?=0.05),P<0.05 for the difference was statistically significant.Results:1.The follow-up results showed that 16 patients had clinical events with target lesions,and the total target lesion failure rate was 9.5%.2.Under the premise of using the new definition of tissue protrusion,the incidence of tissue protrusion detected by OCT was 60.8%.Tissue protrusion of irregular morphology and tissue protrusion of high-risk features accounted for the majority.3.Lipid was the main tissue component of tissue protrusion,and more than half of the lesions with lipid plaques were likely to have tissue protrusion after PCI.Lesions containing thin-cap fibroatheroma(TCFA)or plaque rupture also had an incidence of tissue protrusion of more than80%after PCI.At the same time,these lesions were prone to large-scale tissue protrusion and lipid-rich tissue protrusion.Comparatively,calcified plaques were less involved in the formation of tissue protrusion,especially in high-risk tissue protrusion.4.Tissue protrusion was higher in TLF patients(81.3%),but there was no difference between the groups.According to the morphological classification,large area tissue protrusion(62.5%VS 20.4%,p=0.04)and lipid-rich tissue protrusion(68.8%vs 30.3%,p=0.03)in TLF patients had a higher detection rate.5.In the TLF group,the lipid plaques of target lesions had thinner fibrous caps,longer lipid lengths,and a higher proportion of macrophages before PCI procedure.The TCFA detection rate of these lesions was also higher than that of the no event group.Conclusion:1.The new definition of tissue prolapse is conducive to improving the detection ratio of OCT for high-risk characteristic tissue prolapse.2.OCT analysis showed that lipid plaques were more likely to form coronary wall tissue prolapse.3.Large-area or lipid-rich OCT high-risk features of coronary wall tissue prolapse have an impact on clinical events after coronary stenting.