Overlap Stenting For Long Coronary Lesions With Stent Boost Subtract Guidance Assessed By Optical Coherence Tomography

Objective: During the treatment of long coronary lesions,the target lesion is often longer than a single stent length,two or more overlapping stents are used in order to completely cover the target lesion.When multiple overlapping stents are implanted to treat long coronary lesions,due to the chemical and physical properties of drug-eluting stent overlapping parts,it will delay endothelial cell coverage and impact short-term and long-term prognosis of patients.Therefore,reducing the overlapping parts of drug-eluting stent length during treatment of long coronary lesions will help to improve the prognosis of patients.StentBoost Subtract has unique advantages in enhancing the stent visuality to judge expansion and location of the stents,it will help optimize overlapping stents implantation and expanse well.However,there is no research about the use of SBS in long coronary lesions yet.The purpose of this study was to assess SBS applies in the treatment of long coronary lesions compared with angiography by using OCT.Methods: This study prospectively screened and enrolled patients who underwent PCI confirmed with the inclusion criteria with conventional angiography or SBS guidance for percutaneous coronary artery interventional therapy and OCT after stent deployment from February 2015 to December 2015.All the patients according to whether by SBS guide stent implantation were divided into SBS group and normal CAG group.Inclusion criteria were: 1)age >18 years and<75 years;2)coronary angiography showed lumen diameter stenosis of coronary artery was >70%;3)lesion length more than 30 mm and less than 46mm(two overlapping stents);4)visual reference vessel diameter was 2.5mm-3.5mm;5)with the indications for stent implantation.Exclusion criteria: 1)acute myocardial infarction undergoing emergency PCI;2)graft lesions;3)the left main coronary artery disease;4)distance opening less than 3mm ostial lesion;5)bifurcation lesions;6)complete occlusion lesions;7)calcified lesions.8)can't fulfill OCT and poor OCT/SBS image quality;9)severe complications;10)NYHA?III;11)creatinine(CR)>1.5mg/dl(133umol/L).All patients underwent coronary angiography and OCT examination during the operation,After that Quantitative coronary angiography(QCA)and OCT analysis were carried out to assess SBS applies in the treatment of coronary artery diffuse long lesions and evaluate the effect of overlapping stent implantation about stent expansion and precise positioning.The primary endpoint of the study was overlap length.Secondary endpoints were: stacked struts numbers,amount of clusters,stent expansion index,and stent eccentricity index.Coronary angiography was performed using Alluraxper FD10 or FD20(Philips Healthcare,Best,the Netherlands),and data were digitally record for off-line analysis.QCA analysis was performed for pre-procedure and post-procedure,and coronary angiography data using automated edge-detection software(QAngio XA version 7.2,Medis Medical Imaging System,Netherlands)at a single projection showing the most severe stenosis.The analysis parameters were reference lumen area ? minimal lunmen diameter?diameter stenosis?area stenosis and lesion length.PCI postoperative angiographic images showed in the same angle.SBS was performed by Alluraxper FD10 or FD20(Philips Healthcare,Best,the Netherlands)which was installed SBS analysis system.Optical coherence tomography(OCT)equipment consists of C7-XR Dragonfly imaging catheter,pullback device and OCT console.OCT was performed using standard technique.Data were stored digitally for off-line analysis.The analysis parameters including stent eccentricity index,stent expansion index,and length of the overlapping stents,the stents clusters.Statistical analysis: SPSS 13.0(SPSS Inc.,USA)for windows was used for all analysis.Categorical variables were presented as numbers or percentages and compared using Chi-square statistics or Fisher's exact test as appropriate.Continuous variables were presented as medians and interquartile ranges and compared using Student's t test.Moreover,if normality assumption was violated,Mann-Whitney U test or Wilcoxon signed ranks test would be used.For all comparisons,a P value of <0.05(2-sided)was considered statistically significant.Results: Of 842 patients were screened for participation,46 patients were enrolled in the study,SBS group was 22 patients,CAG group was 23 patients.In the sight of optical coherence tomography(OCT),with similar reference lumen diameter?minimal lumen diameter?diameter stenosis and area stenosis(P>0.05),the stent eccentricity index was significantly larger in SBS group than in CAG group(0.85±0.07 vs 0.80±0.05,P=0.013),the stent expansion index was significantly larger in SBS group than in CAG group(80.27±0.27% vs 78.33±0.36%,P=0.000).In addition,the length of overlapping stents was significantly shorter in SBS group than CAG group(0.85±0.42 mm vs 2.12±0.49 mm,P=0.000).Furthermore the amount of cluster was significantly smaller in SBS group than CAG group(26.49±3.71 vs 48.35±4.86,P=0.000).There were no gaps between two overlapping stents in the SBS group.Conclusion: According to the evaluation of optical coherence tomography,for long coronary lesions treatment,compared with only angiography guiding overlapping stents implantation,SBS has advantages in enhancing the stent visuality and real time guidance during PCI process.So it can help stents expansion better,and guide stents positioning accurately to reduce the length of the overlapping stents.In the perspective of interventional imaging,SBS provides new idea and method for the treatment of long coronary lesions.