XIENCE Stent Research Articles

Impact of everolimus-eluting stent length on long-term clinical outcomes of percutaneous coronary intervention

BackgroundEven though longer stented lengths may increase the risk of restenosis, full coverage of diffuse long lesions with longer stents seems to be the optimal strategy for percutaneous coronary intervention (PCI) in the new drug-eluting stent (DES) era. However, it remains unclear whether this strategy will indicate favorable outcome or not. This study evaluated the impact of stent length on two-year clinical outcomes after PCI with the XIENCE Alpine everolimus-eluting stent. MethodsThis was a retrospective, non-randomized, observational study. Four patient groups were classified according to implanted overall total stent length (short, <15mm; middle, 15–23mm; long, 24–32mm; and ultra-long, >32mm). The primary outcome of this study was major adverse cardiac events (MACE), defined as the composite of cardiac death, recurrent myocardial infarction (MI), target vessel revascularization (TVR), and stent thrombosis (ST). Angiographic restenosis by quantitative coronary angiography was defined as >50% diameter stenosis at 10 months after PCI. ResultsA total of 730 patients who received intravascular ultrasound (IVUS)-guided PCI were enrolled. The short, middle, long, and ultra-long stent groups included 138 patients (149 lesions), 210 patients (235 lesions), 190 patients (209 lesions), and 192 patients (208 lesions), respectively. The primary outcome at two years did not differ among the four groups (MACE: 4.4% in short, 3.3% in middle, 4.7% in long, and 4.7% in ultra-long groups, p=0.402); TVR, ST, MI, and cardiac mortality also did not differ among groups. ConclusionsLong stenting using the XIENCE stent which was guided by IVUS for diffuse, long lesions was associated with favorable clinical outcomes at two years in daily clinical practice.

TCT-429 Comparison of the clinical performance between COMBO and Xience stent at one year follow-up in all-comers patients

TCT-429 Comparison of the clinical performance between COMBO and Xience stent at one year follow-up in all-comers patients

TCT-260 Safety and Effectiveness of XIENCE Stents in Chronic Total Occlusion Revascularization: Long-Term Results from the EXPERT CTO Multicenter Clinical Trial

Limited long term data exists regarding chronic total occlusion (CTO) revascularization with modern techniques and new-generation drug-eluting stents. EXPERT CTO ([NCT01435031][1]) is a prospective, multicenter registration trial examining the safety and effectiveness of XIENCE everolimus eluting

Evaluation of chemical stability of polymers of XIENCE everolimus-eluting coronary stents in vivo by pyrolysis-gas chromatography/mass spectrometry.

The polymers poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(n-butyl methacrylate) (PBMA) are employed in manufacturing the XIENCE family of coronary stents. PBMA serves as a primer and adheres to both the stent and the drug coating. PVDF-HFP is employed in the drug matrix layer to hold the drug everolimus on the stent and control its release. Chemical stability of the polymers of XIENCE stents in the in-vivo environment was evaluated by pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS) detection. For this evaluation, XIENCE stents explanted from porcine coronary arteries and from human coronary artery specimens at autopsy after 2-4 and 5-7 years of implantation, respectively, were compared to freshly manufactured XIENCE stents (controls). The comparison of pyrograms of explanted stent samples and controls showed identical fragmentation fingerprints of polymers, indicating that PVDF-HFP and PBMA maintained their chemical integrity after multiple years of XIENCE coronary stent implantation. The findings of the present study demonstrate the chemical stability of PVDF-HFP and PBMA polymers of the XIENCE family of coronary stents in the in-vivo environment, and constitute a further proof of the suitability of PVDF-HFP as a drug carrier for the drug eluting stent applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1721-1729, 2018.

A randomized multicenter trial comparing the XIENCE everolimus eluting stent with the CYPHER sirolimus eluting stent in the treatment of female patients with de novo coronary artery lesions: The SPIRIT WOMEN study

BackgroundThe comparative performance of different drug-eluting stents (DES) among female patients has not been assessed in a randomized manner.ObjectivesThe SPIRIT Women Clinical Evaluation trial compared the durable polymer everolimus-eluting XIENCE stent (DP-EES) with the durable polymer sirolimus-eluting Cypher stent (DP-SES) in women undergoing percutaneous coronary intervention (PCI).MethodsA total of 455 female patients with stable CAD were randomly assigned to receive DP-EES (n = 304) or DP-SES (n = 151). The powered angiographic outcome of the trial was in-stent late lumen loss (LLL) at 9 months after the index procedure. Secondary angiographic end points included in-segment LLL, in-stent and in-segment binary restenosis and percent diameter stenosis. The primary clinical outcome was a composite of all-cause death, myocardial infarction (MI) or target vessel revascularization (TVR).ResultsAt 9-month follow-up, in-stent LLL was 0.19±0.38 mm and 0.11±0.37 mm in patients assigned to DP-EES and DP-SES, respectively. The one-sided upper 95% CI of the difference in in-stent LLL between the groups of 0.08 mm was 0.15 and therefore within the pre-specified non-inferiority margin of 0.17 mm (p for non-inferiority = 0.013). However, the test for superiority showed a borderline significant difference in terms of LLL between DP-EES and DP-SES (p for superiority = 0.044). There were no significant differences in binary restenosis (2.0% vs. 0.72%, p = 0.44) and percent diameter stenosis (14.97±12.17 vs. 13.36±10.82, p = 0.19). The rate of definite stent thrombosis at 12 months was lower in patients treated with DP-EES (0% vs. 2.0%, p = 0.036).ConclusionsAmong women undergoing PCI, DP-EES was associated with a small but probably clinically relevant increase in in-stent LLL at 9 months as compared to DP-SES and with a lower risk of definite stent thrombosis at 12 months.Trial registrationClinicalTrials.gov NCT01182428.https://clinicaltrials.gov/

Clinical outcomes of biodegradable polymer biolimus-eluting BioMatrix stents versus durable polymer everolimus-eluting Xience stents.

There are limited data about clinical outcomes of biodegradable polymer biolimus-eluting BioMatrix stents (BP-BES) and durable polymer everolimus-eluting Xience stents (DP-EES) in real world practice. We sought to compare the clinical outcomes of BP-BES and DP-EES in real world cohorts of patients undergoing percutaneous coronary intervention. A prospective multicenter registry enrolled 999 patients treated with BP-BES and 1,000 patients treated with DP-EES. The primary outcome was target lesion failure, defined as a composite of cardiac death, target vessel-related myocardial infarction, or target lesion revascularization. Definite or probable stent thrombosis was also compared in total and propensity score-matched cohorts. The median follow-up duration was 24 months, and mean age was 65 years (interquartile range, 56–72 years). Patients receiving BP-BES had a lower prevalence of acute coronary syndrome, prior myocardial infarction, multi-vessel disease, bifurcation lesions, and left anterior descending artery lesions than those receiving DP-EES. After propensity score matching (692 pairs), target lesion failure occurred in 22 patients receiving BP-BES and in 25 patients receiving DP-EES (3.2% versus 3.6%; adjusted hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.53 to 1.60; p = 0.77). The risk of definite or probable stent thrombosis did not differ between the 2 groups (0.4% versus 0.4%; adjusted HR, 1.03; 95% CI, 0.21 to 4.98; p = 0.97). The results were consistent across various subgroups. In the propensity score-matched analysis of real world cohorts, BP-BES showed similar clinical outcomes compared to DP-EES. We need to investigate about whether differences in clinical outcome emerge during long-term follow-up.

Plasmonic photothermal therapy of atherosclerosis with nanoparticles: long-term outcomes and safety in NANOM-FIM trial.

The safety options in nanomedicine raise an issue of the optimal niche at the real-world clinical practice. This is an observational prospective cohort analysis of the 5-year clinical outcomes at the intention-to-treat population (nano vs ferro vs stenting; n = 180) of NANOM first-in-man trial (NCT01270139). Mortality (6 vs 9 vs 10 cases of cardiac death in groups, p < 0.05), major adverse cardiovascular events (14.3 vs 20.9 vs 22.9%, p = 0.04), late thrombosis (2 vs 4 vs 6, p < 0.05) and target lesion revascularization (3.8 vs 4.8 vs 5.7%, p = 0.04) were significantly higher in ferro group and stent control at 60 months. NANOM first-in-man trial demonstrates high safety with better rate of mortality, major adverse cardiovascular events and target lesion revascularization at the long-term follow-up if compare with stent XIENCE V.

Economic Outcomes of Bioresorbable Vascular Scaffolds Versus Everolimus-Eluting Stents in Patients Undergoing Percutaneous Coronary Intervention: 1-Year Results From the ABSORB III Trial

ObjectivesThe purpose of this study was to evaluate the economic impact of the Absorb bioresorbable vascular scaffold compared with the Xience everolimus-eluting stent in patients undergoing percutaneous coronary intervention. BackgroundThe ABSORB III trial (Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease) demonstrated that the Absorb scaffold was noninferior to the Xience stent with respect to target lesion failure at 1 year. Whether health care costs differ between the Absorb scaffold and the Xience stent is unknown. MethodsWe performed a prospective health economic study alongside the ABSORB III trial, in which patients undergoing percutaneous coronary intervention for stable or unstable angina were randomized to receive the Absorb scaffold (n = 1,322) or Xience stent (n = 686). Resource use data were collected through 1 year of follow-up. Costs were assessed using resource-based accounting (for procedures), MedPAR data (for other index hospitalization costs), and Medicare reimbursements (for follow-up costs and physician fees). ResultsInitial procedural costs were higher with the Absorb scaffold than the Xience stent ($6,316 ± 1,892 vs. $6,103 ± 1,895; p = 0.02), driven mainly by greater balloon catheter use and the higher cost of the scaffold in the Absorb group. Nonetheless, index hospitalization costs ($15,035 ± 2,992 for Absorb vs. $14,903 ± 3,449 for Xience; p = 0.37) and total 1-year costs ($17,848 ± 6,110 for Absorb vs. $17,498 ± 7,411 for Xience; p = 0.29) were similar between the 2 groups. ConclusionsAlthough initial procedural costs were higher with the Absorb scaffold, there were no differences in total 1-year health care costs between the 2 cohorts. Longer term follow-up is needed to determine whether meaningful cost savings emerge after scaffold resorption. (A Clinical Evaluation of Absorb™ BVS, the Everolimus-Eluting Bioresorbable Vascular Scaffold in the Treatment of Subjects With de Novo Native Coronary Artery Lesions; NCT01751906)

Crimping and deployment of metallic and polymeric stents -- finite element modelling

Aim: This paper aims to compare the mechanical performance of metallic (Xience) and bioresorbable polymeric (Elixir) stents during the process of crimping and deployment. Methods: Finite element software ABAQUS was used to create the geometrical models and meshes for the balloon, stent and diseased artery. To simulate the crimping of stents, 12 rigid plates were generated around the stent and subjected to radially enforced displacement. The deployment of both stents was simulated by applying internal pressure to the balloon, where hard contacts were defined between balloon, stent and diseased artery. Results: Elixir stent exhibited a lower expansion rate than Xience stent during deployment. The stent diameter achieved after balloon deflation was found smaller for Elixir stent due to higher recoiling. Lower level of stresses was found in the plaque and artery when expanded by Elixir stent. Reduced expansion, increased dogboning and decreased vessel stresses were obtained when considering the crimping-generated residual stresses in the simulations. Conclusion: There is a challenge for polymeric stents to match the mechanical performance of metallic stents. However, polymeric stents impose lower stresses to the artery system due to less property mismatch between polymers and arterial tissues, which could be clinically beneficial.

Reduced duration of dual antiplatelet therapy using an improved drug-eluting stent for percutaneous coronary intervention of the left main artery in a real-world, all-comer population: Rationale and study design of the prospective randomized multicenter IDEAL-LM trial

Continuous improvements in stent technology make percutaneous coronary intervention (PCI) a potential alternative to surgery in selected patients with unprotected left main coronary artery (uLMCA) disease. The optimal duration of dual antiplatelet therapy (DAPT) in these patients remains undetermined, and in addition, new stent designs using a bioabsorbable polymer might allow shorter duration of DAPT. IDEAL-LM is a prospective, randomized, multicenter study that will enroll 818 patients undergoing uLMCA PCI. Patients will be randomized in a 1:1 fashion to intravascular ultrasound-guided PCI with the novel everolimus-eluting platinum-chromium Synergy stent with a biodegradable polymer (Boston Scientific, Natick, MA) followed by 4 months of DAPT or the everolimus-eluting cobalt-chromium Xience stent (Abbott Vascular, Santa Clara, CA) followed by 12 months of DAPT. The total follow-up period will be 5 years. A subset of 100 patients will undergo optical coherence tomography at 3 months. The primary end point will be major adverse cardiovascular events (composite of all-cause mortality, myocardial infarction, and ischemia-driven target vessel revascularization) at 2 years. Secondary end points will consist of the individual components of the primary end point, procedural success, a device-oriented composite end point, stent thrombosis as per Academic Research Consortium criteria, and bleeding as per Bleeding Academic Research Consortium criteria. IDEAL-LM is designed to assess the safety and efficacy of the novel Synergy stent followed by 4 months of DAPT vs the Xience stent followed by 12 months of DAPT in patients undergoing uLMCA PCI. The study will provide novel insights regarding optimal treatment strategy for patients undergoing PCI of uLMCA disease (www.clinicaltrials.gov, NCT 02303717).

Undesired Outcomes of the Catania Stent Compared to the Xience Stent in Patients Undergoing Angioplasty: A Double-Blind Randomized Controlled Trial.

Background:The present study tries to compare the unintended outcomes of the Catania stent versus Xience stent in patients undergoing angioplasty.Materials and Methods:In a three month, follow-up, double-blinded, randomized controlled trial, 83 patients undergoing angioplasty, who met the inclusion criteria were entered into the study. After randomization 43 patients were treated with the Xience stent and 40 patients with the Catania stent. Stent-related outcomes such as Cardiac and Non-Cardiovascular Death, Myocardial Infarction (MI), Target Lesion Revascularization (TLR), Stent Thrombosis (ST), Coronary Artery Bypass Grafting (CABG), Peripheral vasculopathy, and Cerebral Vascular Accident (CVA) were compared between the groups.Results:There was no statistically significant difference in the incidence rate of complications and clinical outcomes between the two treatment groups (P > 0.05). The incidence of MI, TLR, CABG operation, peripheral vasculopathy, or CVA was not observed in any patient and there was no statistically difference in mortality (4.7% vs. 2.5%; P = 0.527) and stent thrombosis (2.3% vs. 2.5%; P = 0.735).Conclusion:All in all, the present study could not find the significant differences between the Catania stent and Xience stent in terms of clinical outcomes during the follow-up period.

Prospective rAndomized, single-blind, mulTicenter control clinical study of sirolimus-eluting coRonary stent “Calypso” vs everolimus-elutIng cOronary stenT “Xience Prime”: design and rationale for “PATRIOT” trial

Aim. This study is aimed at evaluating the efficacy and safety of sirolimus-eluting coronary stent “Calypso” in comparison with everolimus-eluting coronary stent “Xience Prime” in patients with ischemic heart disease. Methods. This is a prospective, randomized, single-blind multicenter clinical trial in patients undergoing coronary revascularization with coronary stenting. Seven clinical sites in Russia will enroll 610 patients with coronary artery disease. Patients suitable for coronary stenting will be randomized in group 1 (n=406) to receive coronary stent “Calypso” (“Angioline”, and group 2 (n=204) to receive coronary stent Xience Prime (Abbott). Clinical follow-up will continue for 1 year. By the end of follow-up, a quantitative coronary angiography will be performed in 122 patients (20 %). Conclusion. A randomized trial “PATRIOT” is designed to prove the efficacy and safety of sirolimus-eluting coronary stent “Calypso” in comparison with everolimus-eluting coronary stent “Xience Prime” in patients with ischemic heart disease.Received 5 October 2016. Accepted 6 December 2016.Funding: This study was funded by “Angioline Interventional Devices”, 630090, 18 Inzhenernaya Street, Novosibirsk, Russian Federation. Conflict of interest: The authors declare no conflict of interest.

TCT-474 Ten-year follow-up of the Xience stent in 7655 consecutive patients: single center registry results

Safety and effectiveness of the XIENCE stent in the real world have been previously demonstrated with low rates of target lesion revascularization (TLR), cardiac death, myocardial infarction (MI) and stent thrombosis (ST) up to 2 years. Whether these results are sustained over long-term FU has not

Randomised comparison of a bioresorbable everolimus-eluting scaffold with a metallic everolimus-eluting stent for ischaemic heart disease caused by de novo native coronary artery lesions: the 2-year clinical outcomes of the ABSORB II trial.

The one-year randomised data of the ABSORB II trial showed that the everolimus-eluting bioresorbable scaffold and the everolimus-eluting metallic stent were comparable for the composite secondary clinical outcomes of patient-oriented composite endpoint (PoCE) and device-oriented composite endpoint (DoCE)/target lesion failure (TLF), MACE and TVF. This report describes the two-year clinical outcomes of the ABSORB II trial. Patients were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting bioresorbable scaffold (Absorb; Abbott Vascular, Santa Clara, CA, USA) or treatment with an everolimus-eluting metallic stent (XIENCE; Abbott Vascular). The trial enrolled 501 patients. Clinical follow-up at two years was available in 320 patients in the Absorb BVS arm and 160 patients in the XIENCE arm. At two years, the PoCE for the Absorb and XIENCE arms was 11.6% and 12.8% (p=0.70) and the DoCE/TLF was 7.0% and 3.0% (p=0.07), respectively. The hierarchical ID-MACE rate was 7.6% vs. 4.3% (p=0.16) and the rate of TVF was 8.5% vs. 6.7% (p=0.48). The definite/probable thrombosis rate was 1.5% in the Absorb arm vs. 0% in the XIENCE arm (p=0.17). Thirty-six percent and 34% of patients remained on DAPT at two years, respectively. Ninety-two percent of patients in both arms remained on aspirin. Two-year clinical results demonstrate sustained low rates of PoCE, MACE, DoCE and TVF with the Absorb BVS as compared to the XIENCE stent.

Bioresorbable polymer sirolimus-eluting coronary stent compared with permanent polymer everolimus-eluting coronary stent implantation for treatment of small vessel coronary artery disease: CENTURY II trial.

CENTURY II is a prospective, multicentre, randomised, single-blind trial comparing the bioresorbable polymer sirolimus-eluting Ultimaster® stent (BP-SES) with the permanent polymer everolimus-eluting XIENCE stent (PP-EES). Here we present a pre-specified analysis of safety and efficacy outcomes in a subgroup of patients with small vessel coronary artery disease. CENTURY II included 525 patients with lesions of reference diameter ≤2.5 mm. Treatment was randomly assigned: 277 patients received BP-SES (399 lesions) and 248 patients received PP-EES (377 lesions). The primary outcome was target lesion failure (TLF), which is a composite of cardiac death, target vessel-related myocardial infarction (MI) and target lesion revascularisation (TLR). There was no significant difference between treatment groups in baseline or procedural data. Mean pre-procedural reference diameter was similar (BP-SES 2.30±0.40 mm, PP-EES 2.31±0.42 mm, p=0.59). Stented length was 24.0±11.7 mm for BP-SES and 23.5±11.5 mm for PP-EES (p=0.45). At 12 months, there was no significant difference between the BP-SES and PP-EES groups in TLF (6.9% vs. 7.7%; p=0.72), cardiac death (1.1% vs. 1.2%; p=0.90), target vessel MI (1.8% vs. 3.2%; p=0.30), TLR (4.0% vs. 5.7%; p=0.37), or definite or probable stent thrombosis (0.7% vs. 1.2%; p=0.57). In the large-scale, randomised CENTURY II trial, use of BP-SES and PP-EES for the treatment of small vessel coronary artery disease resulted in similar outcomes at 12 months.

Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease

BackgroundIn patients with coronary artery disease who receive metallic drug-eluting coronary stents, adverse events such as late target-lesion failure may be related in part to the persistent presence of the metallic stent frame in the coronary-vessel wall. Bioresorbable vascular scaffolds have been developed to attempt to improve long-term outcomes.MethodsIn this large, multicenter, randomized trial, 2008 patients with stable or unstable angina were randomly assigned in a 2:1 ratio to receive an everolimus-eluting bioresorbable vascular (Absorb) scaffold (1322 patients) or an everolimus-eluting cobalt–chromium (Xience) stent (686 patients). The primary end point, which was tested for both noninferiority (margin, 4.5 percentage points for the risk difference) and superiority, was target-lesion failure (cardiac death, target-vessel myocardial infarction, or ischemia-driven target-lesion revascularization) at 1 year.ResultsTarget-lesion failure at 1 year occurred in 7.8% of patients in the Absorb group and in 6.1% of patients in the Xience group (difference, 1.7 percentage points; 95% confidence interval, −0.5 to 3.9; P=0.007 for noninferiority and P=0.16 for superiority). There was no significant difference between the Absorb group and the Xience group in rates of cardiac death (0.6% and 0.1%, respectively; P=0.29), target-vessel myocardial infarction (6.0% and 4.6%, respectively; P=0.18), or ischemia-driven target-lesion revascularization (3.0% and 2.5%, respectively; P=0.50). Device thrombosis within 1 year occurred in 1.5% of patients in the Absorb group and in 0.7% of patients in the Xience group (P=0.13).ConclusionsIn this large-scale, randomized trial, treatment of noncomplex obstructive coronary artery disease with an everolimus-eluting bioresorbable vascular scaffold, as compared with an everolimus-eluting cobalt–chromium stent, was within the prespecified margin for noninferiority with respect to target-lesion failure at 1 year. (Funded by Abbott Vascular; ABSORB III ClinicalTrials.gov number, NCT01751906.)

Multisector-reconstruction in 1st generation 320-slice CT at high pulsation-rates achieved accurate-evaluation of coronary-lumen patency after insertion of a XIENCE stent. XIENCE Phantom Study Part 4

Multisector-reconstruction in 1st generation 320-slice CT at high pulsation-rates achieved accurate-evaluation of coronary-lumen patency after insertion of a XIENCE stent. XIENCE Phantom Study Part 4 Nobusada Funabashi ⁎, Yasuaki Namihira , Ryosuke Irie , Yoshihide Fujimoto , Toshihiro Shoji , Hiroyuki Takaoka , Hironori Kondo , Kanako Atou , Joji Ota , Yoshitada Masuda , Takashi Uno , Yoshio Kobayashi a

Comparison of sirolimus eluting stent with bioresorbable polymer to everolimus eluting stent with permanent polymer in bifurcation lesions: Results from CENTURY II trial.

To demonstrate the safety and efficacy of a new sirolimus eluting stent with bioresorbable polymer, Ultimaster, (BP-SES) compared with everolimus-eluting, permanent polymer, Xience stent (PP-EES) in bifurcation lesions with respect to the freedom from Target Lesion Failure at 1-year. Within 1,119 patients enrolled in the CENTURY II randomized controlled multicenter trial, 194 patients were treated for bifurcation lesions and randomized to either BP-SES (n = 95) or PP-EES (n = 99). The primary endpoint was freedom from target lesion failure (TLF) composite endpoint [cardiac death, MI not clearly attributable to a non-target vessel, and clinically driven target lesion revascularization (TLR)] at 1-year. Baseline patient demographic, angiographic, and stenting characteristics were similar in both study arms. A single stent technique with provisional or "cross over" stenting were the most widely used in both arms (93.2% BP-SES vs. 92.4% PP-EES). Freedom from TLF at 1-year was 94.7% for BP-SES and 91.9% for PP-EES (P for noninferiority 0.031). The rate of clinically driven target lesion revascularization (TLR) at 1-year was 3.2% for BP-SES and 3.0% for PP-EES (P = 0.95). There were no significant differences detected in any of the individual clinical endpoints or other secondary clinical endpoints between the study arms at 1-year follow up. The new bioresorbable polymer sirolimus-eluting stent showed safety and efficacy profiles similar to durable polymer everolimus-eluting in the treatment of patients with bifurcation lesions at 1-year follow up. © 2015 Wiley Periodicals, Inc.

A study of balloon type, system constraint and artery constitutive model used in finite element simulation of stent deployment

Abstract Background Finite element is an effective tool to simulate stent expansion inside stenotic arteries, which provides an insightful understanding of the biomechanical behaviour of the whole stent-artery system during the procedure. The choice of balloon type, system constraint and artery constitutive model plays an important role in finite element simulation of stent deployment. Methods Commercial finite element package ABAQUS was used to model the expansion of Xience stent inside a diseased artery with 40% stenosis. The arterial wall, consisting of intima, media and adventitia layers, and the stenotic plaque were described by different hyperelastic models. Both folded and rubber balloons were considered and inflated with a linearly increasing pressure of 1.4 MPa. Simulations were also carried out by considering free, partially and fully constrained arteries. Results Folded balloon produces sustained stent expansion under a lower pressure when compared to rubber balloon, leading to increased stress level and enhanced final expansion for the system. Fully constrained artery reduces the stent expansion when compared to free and partially constrained arteries, due to the increased recoiling effect. Stress in the artery-plaque system has higher magnitude for stent expansion in a free artery due to more severe stretch. Calcified plaque limits stent expansion considerably when compared to hypocellular plaque. The negligence of the second stretch invariant in the strain energy potential leads to the disappearance of saturation behaviour during stent expansion. The use of anisotropic artery model reduces the system expansion at peak pressure when compared to the isotropic model, but with an increased final diameter due to reduced recoiling effect. The stress distribution in the artery-plaque system is also different for different combinations of artery and plaque constitutive models. Conclusions Folded balloon should be used in the simulation of stent deployment, with the artery partially constrained using spring elements with a proper stiffness constant. The blood vessel should be modelled as a three-layer structure using a hyperelastic potential that considers both the first and second stretch invariants as well as the anisotropy. The composition of the plaque also has to be considered due to its major effect on stent deployment.

HOW TO IMPROVE EVALUATION OF PATENCY OF CORONARY ARTERIAL LUMEN SURROUNDED BY XIENCE STENT LESS THAN 2.5 MM IN DIAMETER IN 320 SLICE CT USING PULSATING PHANTOM COMPARED WITH OPTICAL COHERENCE TOMOGRAPHY

By 2010 ACCF appropriate use criteria for cardiac CT, evaluation of patency of coronary arteries surrounded by a stent <3 mm diameter is inappropriate. At present, the everolimus-eluting stent (XIENCE Prime, Abbot) is often used. In an in vitro study, a XIENCE stent (3mm diameter) was attached to a