Individualized Study Of Percutaneous Coronary Intervention In Patients With Coronary Artery Disease

Objectives:The traditional cylindrical stent currently used in the percutaneous coronary intervention(PCI)has a consistent diameter,which does not match the physiological change of the coronary artery.Therefore,there will exist stent malapposition on the proximal vessel or stent overexpansion on the distal vessel after traditional cylindrical stent implantation,which may prone to lead stent thrombosis and stent restenosis,resulting in adverse cardiovascular events.On the contrary,as a new patent,the personalized conical stent with tapering lumen is consistent with the physiological change of vascular diameter.However,the effect of the personalized conical stent implantation on the coronary hemodynamics remains unclear.This study sought to explore the efficacy of the personalized conical stent implantation in the coronary artery by comparing the effects of cylindrical and conical stent on wall shear stress(WSS),velocity of flow and fractional flow reserve(FFR).Methods:The coronary artery,artery stenosis and two stent models were established by Solidworks software.All models were imported into the computational fluid dynamics(CFD)software ANSYS ICEM-CFD to establish the fluid model.After establish the vessels and stent model,the boundary conditions were set.The partitioned grid was imported into the ANSYS Fluent software to calculate,and after calculation,results were saved for further analysis.CFD analysis was proceeded to compare the effects of two stents implantation on the change of WSS,velocity of flow and FFR.Results:Hemodynamic indexes including FFR,blood flow velocity distribution(BVD)and WSS were improved by either the cylindrical or the personalized conical stent implantation.Before stent implantation,FFR on the stenosis was significantly lower than normal blood vessels.In contrast,FFR was significantly improved after either the cylindrical stent or conical stent implantation which suggested that both stents were effective in treating stenosis.Before stent implantation,blood flow velocity on the stenosis was significantly faster,while the speed was not uniform,and the flow was disturbed,which was easy to cause plaque rupture and acute cardiovascular events.In contrast,the blood flow velocity was significantly decreased and became evener after implanting both two stents.Before the stent implantation,WSS on the stenosis site was significantly higher than normal blood vessels with evenly distribution,especially in the narrowest place.The increased WSS on the stenosis was easier to form vortexes when blood flow through and induce the plaque rupture.In contrast,WSS was significantly improved after either the cylindrical stent or the conical stent implantation.However,after the personalized conical stent implantation,the change of FFR seemed to be slower and more homogenous;the blood flow velocity was more appropriate without any obvious blood stagnation and direction changes;the WSS after the conical stent implantation was uniform from the proximal to distal side of the stent.Conclusions:The present study provides us a new insight from the perspective of the stent configuration.Compared with the cylindrical stent,the personalized conical stent implantation in the coronary artery can make the changes of vascular hemodynamic more closer to the physiological condition,which can reduce the incidence of intra-stent restenosis and thrombosis,thus making it more suitable for PCI therapy.Objectives:When patients with coronary artery disease(CAD)undergoing percutaneous coronary intervention(PCI),obtaining complete revascularization(CR)is an ideal goal for both physicians and patients themselves.But to elderly diabetes patients,It's very difficult to achieve CR in most situations.When determining to obtain incomplete revascularization(ICR),unfortunately,the degree of revascularization for those patients during PCI procedure remains unknown.In this article,we use the index named the SYNTAX Revascularization Index(SRI)to evaluate the degree of revascularization.We sought to determine the prognostic utility of the SRI among elderly diabetes patients undergoing PCI.Methods: We performed a retrospective analysis,which was conducted of 1,055 diabetes patients over 70 years old who underwent PCI at Beijing Anzhen Hospital from January 2012 to December 2013.The baseline SYNTAX score(b SS)and residual SYNTAX score(r SS)of each angiogram were independently calculated by 3 experienced interventional physicians who were blinded to randomization and clinical outcomes.SRI was calculated by the following formula: SRI=(1–[r SS/b SS])×100%.All patients were divided into three groups according to the SRI value: SRI=100%(complete revascularization),50-99%,and <50%.Adverse ischemic outcomes between different groups were compared at two year.Results:The mean values of b SS were 10.27±7.68,18.46±8.27 and 20.27±9.33.The mean values of r SS were 0,5.16±3.86 and 15.35±7.92.The mean values of SRI(%)were 100,72.40±13.66 and 24.58±15.27.The SRI was 100% in 261 patients(24.8%),50-99% in 385 patients(36.6%),and <50% in 409 patients(38.9%).Two-year adverse ischemic outcomes,including major adverse cardiovascular event(MACE),death,myocardial infarction(MI),recurrent angina and unplanned revascularization for ischemia were inversely proportional to the SRI(MACE: 12.6% vs.19.5% vs.28.5%;Death: 0.8% vs.2.3% vs.3.9%;MI: 5.0% vs.7.5% vs.10.8%;Recurrent angina: 26.4% vs.36.7% vs.54.7%;Unplanned revascularization for ischemia: 10.3% vs.15.3% vs.21.3%).An SRI cut-off = 65%(present in 532 [50.6%] patients after PCI)had the best prognostic accuracy for prediction of death(area under the curve 0.65,95% confidence interval [CI]: 0.57-0.72,p<0.001).By multiple logistic analysis,the SRI was an independent protective factor for two-year death(OR 0.36,95%: 0.17-0.78,p=0.010).Conclusions: The SRI is a newly described index for quantifying the proportion of CAD burden treated by PCI.Given its correlation with adverse ischemic outcomes,the SRI may be useful in assessing the degree of revascularization after PCI,with SRI >65% representing a reasonable goal for elderly diabetes patients.And incomplete revascularization may become a reasonable choice for elderly diabetes patients when it's difficult to achieve complete revascularization.