The Clinical Analysis Of Related Factors Of Restenosis After PCI In Patients With Coronary Heart Disease

Objective and BackgroundImplantation of drug-eluting stents(DES) has significantly reduced the incidence of restenosis compared to bare-metal stents. However, in-stent restenosis(ISR) has not been thoroughly solved, there is still 10% of the rate of restenosis. With wider use of DES, clinicians encounter an increasing number of patients with DES-related ISR in daily practice. However, to date, there is no established standard treatment for ISR after the implantation of DES. How to prevent and treat the restenosis of the DES era is the focus and difficulty of the current interventional treatment of coronary heart disease. At present about the influence on the occurrence and development of restenosis after coronary stent have different factors associated with various reports, therefore, it is of great significance to explore the related risk factors of restenosis after PCI in patients with coronary heart disease. The aim of this study is to evaluate the clinical, coronary artery lesion, stent related factors, and to identify high risk in patients with stent restenosis and to take active preventive measures to reduce the rate of stent restenosis and improve the long-term prognosis of patients.MethodsIn this retrospective analysis, we analyzed 1342 patients in the affiliated hospital of Zunyi Medical College who were diagnosed with coronary heart disease by coronary angiography, underwent PCI and follow-up coronary angiography after 6~8 months. These patients were divided into the restenosis group( ≥ 50% diameter stenosis of in-stent) and non-restenosis group according to the result of coronary angiography. The restenosis group are 89 patients(94 lesions), and the non-restenosis group are 1253 patients(1754 lesions). Make a retrospective analysis of the two groups of patients’ history data, blood biochemical index, echocardiographic index, coronary artery lesion, stents, medication compliance and major adverse cardiac events by multivariate models for the ability to predict the occurrence of ISR.Results1. The incidence of ISR was 6.6% in the selected patients.2. Our data revealed that diabetes, smoking, statin doses, discontinuing aspirin, the discontinuation of clopidogrel in 1 year, reference vessel diameter before procedure, complex lesions, the diameter or length of previously implanted DES, serial stents, minimum lumen diameter(MLD), the percent of diameter stenosis and acute gain were associated with an increased risk for ISR(P < 0.05).1) The prevalence of diabetes, smoking rate, patients with the discontinuation of clopidogrel in 1 year and discontinuation of aspirin in patients with proportion were significantly higher in ISR group, as compared with non-ISR group.2) The proportion of ISR group taking adequate statin was lower than that of non-ISR group.3) The complex lesions, reference vessel diameter before procedure, series stent in the ISR group were higher than in non-ISR group; The stent length were longer in ISR group than in non-ISR group; The stent diameter and postoperative MLD were smaller and the percent of diameter stenosis was significantly greater in ISR group than in non-ISR group; The acute gain was lower in ISR group than in non-ISR group.4) There was no statistical significance in male, age, hypertension, family history of coronary heart disease, acute myocardial infarction(AMI), old myocardial infarction(OMI), low density lipoprotein cholesterin(LDL-C) level, left ventricular ejection fractions, the stent type and angiotensin-converting enzyme inhibitors/angiotensin II receptor blocker between ISR group and non-ISR group(P>0.05).3. Multiariable logistic regression analysis showed that diabetes, smoking, discontinuing aspirin, diameter or length of previously implanted DES, postoperative MLD, serial stents, and the percent of diameter stenosis are independent risk factors for restenosis after percutaneous coronary intervention.4. At 8 months follow-up, the incidence of recurrent angina, target lesion revascularization(TLR) and combined major adverse cardiovascular events(MACE) in ISR group was significantly higher than in non-ISR group(P<0.001), while myocardial infarction(MI), target vessel revascularization(TVR), heart failure, severe arrhythmia were no significant differences in both groups(P>0.05); At 1 year follow-up found that the incidence of recurrent angina, MI, TLR, composite MACE were significantly higher in ISR group than in non-ISR group(P<0.05), and there was no significant difference in TVR, heart failure and severe arrhythmia between two groups(P>0.05). The incidence of stent thrombosis was significantly higher in ISR group than in non-ISR group(P<0.001).Conclusion1. diabetes, smoking, discontinuing aspirin, the diameter or length of previously implanted DES, postoperative MLD and the percent of diameter stenosis are risk factors for the development of ISR.1) ISR was positively correlated with diabetes, smoking and discontinuing aspirin.2) ISR was positively correlated with the length of previously implanted DES, serial stents and the percent of diameter stenosis; ISR was negatively correlated with postoperative MLD and the diameter of previously implanted DES.3) Hypertension, AMI and OMI did not increase the incidence of restenosis.2. Restenosis after PCI may increase the incidence of MACE.Background: Late in-stent restenosis(ISR) is an important clinical issue in the drug-eluting stent(DES) era. Autopsy studies have reported different underlying mechanisms between early ISR and late ISR. Currentlly, The neointimal tissue appearance between early ISR and very late ISR after DES implantation remains unknown. Although intravascular ultrasound(IVUS) can be used to evaluate neointima distribution within the stented segment, it cannot effectively determine the characteristics of in-stent neointimal tissues. Optical coherence tomography(OCT) is the most advanced technique in detecting intravascular lesions, the typical OCT image has an axial resolution of 10 to 20μm, which is 10 times higher than that of IVUS. OCT not only can provide the detailed information about restenotic tissue(tissue structure, backscatter, microvessels, and composition), but also can identify vulnerable plaque, which has important significance for evaluating patients’ prognosis and making clinical decision.Objective: We used OCT to analyse the morphological differences of tissue characteristics between early and very late restenosis lesions after DES implantation.Methods: In 25 patients(DES) with ISR, OCT images were acquired before percutaneous coronary intervention(PCI). We compared the morphological characteristics of early in-stent restenosis(<18 months: E-ISR, n =14) and very late ISR(>3years: VL-ISR, n=11). The quantitative and qualitative analysis of the entire stent and the minimum lumen area(MLA) site were carried out respectively. OCT quantitative restenotic tissue analysis included the assessment of neointimal area, lumen area, stent area and neointimal burden. OCT qualitative restenotic tissue analysis included the assessment of tissue structure [homogeneous or heterogeneous intima(thin-cap fibroatheroma(TCFA)-like intima, lipid-rich neointima) ], presence of microvessels, disrupted intima with cavity, intraluminal materia and tissue prolapse and was performed at every 1-mm slice of the entire stent.Results:1. The proportions of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group compared to the E-ISR group(60.57%vs. 32.93%, P=0.005). Similarly, both peristent and intraintimal microvessels were more frequently observed in the VL-ISR group(P<0.05). In addition, lipid-rich neointima(72.7% vs. 21.4%, P=0.017), TCFA-like intima(54.5% vs. 7.1%, P=0.021), disrupted intima with visible cavity(63.6% vs. 7.1%, P=0.007), and intraluminal materials(63.6% vs. 7.1%, P=0.007) also were observed more frequently in the VL-ISR group for the entire stent.2. The heterogeneity was observed more frequently in the VL-ISR group(90.9% vs. 35.7%, P=0.012) at the MLD sites. Intraintimal microvessels, disrupted intima with visible cavity and intraluminal materials were observed only in the VL-ISR group. Although there was no significant difference between the two groups in the peristent microvessels, the VL-ISR group was higher than that of E-ISR group.3. Compared with homogeneity intima, the information of heterogeneous intima may be associated with the stent age and acute coronary syndrome at follow-up. In addition, Intraintimal microvessels(11.26% vs 0.0%, P = 0.018), disrupted intima with visible cavity(53.3% vs 0.0%, P = 0.008) and intraluminal materials(53.3% vs 0.0%, P = 0.008) were observed only in the heterogeneous intima group.Conclusion:1. OCT imaging indicated that the morphological characteristics of restenotic tissue in VL-ISR were different from those in E-ISR.2. It was found that atherosclerotic progression of neointima, such as lipid-rich neointima, microchannels and disrupted intima with cavity was more often observed in VL-ISRlesions after DES implantation compared with E-ISR.3. Progression of the atherosclerotic process within neointima after DES implantation may be associated with VL-ISR.Background: Recent data have reported that in-stent neoatherosclerosis(ISNA) could develop long after stent implantation and lead to subsequent rupture and acute coronary syndrome(ACS). Drug-eluting stent(DES) have dramatically reduced restenosis rates, at the same time, their use has been associated with an increased risk of late or very late stent thrombosis and accelerated neointimal atherosclerosis. In-stent restenosis(ISR) mainly results from aggressive neointimal proliferation, but recent data also suggest that ISNA may play an important pathophysiological role.Objective: Application of optical coherence tomography(OCT) to evaluate the incidence, imaging features and related influencing factors of ISNA in patients with restenosis after drug eluting stent implantation.Methods: In 25 patients(DES) with ISR, OCT images were acquired before percutaneous coronary intervention(PCI). These patients were divided into the ISNA group and non-ISNA group according to the result of OCT. The ISNA group are 12 patients(12 lesions), and the non-ISNA group are 13 patients(13 lesions). Neoatherosclerosis on OCT was defined as neointima formation with the presence of lipids or calcification.Results:1. The incidence of ISNA was 48.0% in selected cases.2. Chronic kidney disease(CKD) and low density lipoprotein cholesterin(LDL-C) level were significant predictors for ISNA after drug-eluting stent implantation. In addition, ISNA group was based on ACS(66.7%), non-ISNA group was based on stable anginapectoris(76.9%) in clinical presentation at follow-up(P < 0.05).3. Quantitative analysis of OCT: There were significant difference in the mean lumen area, mean neointimal area, mean neointimal load, mean neointimal thickness between the two groups(P < 0.05). The mean lumen area was less in ISNA group than in non-ISNA group(3.45±1.82mm2 vs. 4.17±1.68mm2, P<0.001), mean neointimal area(4.01±1.92mm2 vs. 3.45±1.95mm2, P=0.003), mean neointimal load(53.73±18.10% vs. 45.38±17.47%, P<0.001), mean neointimal thickness(1.03±0.46μm vs. 0.80±0.39μm, P<0.001) were higher in ISNA group than in non-ISNA group.4. Qualitative analysis of OCT: The homogeneous intima was observed more frequently in the non-ISNA group(72.06% vs. 41.42%, P=0.001), on the contrary, the heterogeneous intima was common in the ISNA group(58.57% vs. 27.94%, P=0.001). Although there was no significant difference between two groups in the peristent microvessels( P>0.05), the intraintimal microvessels were mainly found in the ISNA group(58.3% vs. 15.4%, P=0.041). In addition, thin cap fibrous plaque, disrupted intima with visible cavity were higher in ISNA group than in non- ISNA group(58.3% vs. 7.7%, P=0.011).Conclusion:1. Our data show that ISNA occurs more frequently in patients with ISR after drug-eluting stent implantation.2. The stent age, incidence of CKD and LDL- C level may participate in the formation of ISNA.3. The ISNA may be related to ISR and late or very late stent thrombosis.