ResearchPad - stent-implantation https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[The adipokine vaspin is associated with decreased coronary in-stent restenosis <i>in vivo</i> and inhibits migration of human coronary smooth muscle cells <i>in vitro</i>]]> https://www.researchpad.co/article/elastic_article_7692 Percutaneous coronary intervention represents the most important treatment modality of coronary artery stenosis. In-stent restenosis (ISR) is still a limitation for the long-term outcome despite the introduction of drug eluting stents. It has been shown that adipokines directly influence vessel wall homeostasis by influencing the function of endothelial cells and arterial smooth muscle cells. Visceral adipose tissue-derived serpin vaspin was recently identified as a member of serine protease inhibitor family and serveral studies could demonstrate a relation to metabolic diseases. The aim of this study was to investigate a role of vaspin in the development of in-stent restenosis in vivo and on migration of smooth muscle cells and endothelial cells in vitro.MethodsWe studied 85 patients with stable coronary artery disease who underwent elective and successful PCI with implatation of drug eluting stents. Blood samples were taken directly before PCI. Vaspin plasma levels were measured by specific ELISA. ISR was evaluated eight months later by coronary angiography. Human coronary artery smooth muscle cells (HCASMC) and human umbilical vein endothelial cells (HUVEC) migration was analyzed by an in-vitro migration assay with different concentrations (0.004ng/mL up to 40ng/mL) of vaspin as well as by an scratch assay. For proliferation an impedance measurement with specialiced E-Plates was performed.ResultsDuring the follow up period, 14 patients developed ISR. Patients with ISR had significantly lower vaspin plasma levels compared to patients without ISR (0.213 ng/ml vs 0.382 ng/ml; p = 0.001). In patients with plasma vaspin levels above 1.35 ng/ml we could not observe any restenosis. There was also a significant correlation of plasma vaspin levels and late lumen loss in the stented coronary segments. Further we could demonstrate that vaspin nearly abolishes serum induced migration of HCASMC (100% vs. 9%; p<0.001) in a biphasic manner but not migration of HUVEC. Proliferation of HCASMC and HUVEC was not modulated by vaspin treatment.ConclusionWe were able to show that the adipokine vaspin selectively inhibits human coronary SMC migration in vitro and has no effect on HUVEC migration. Vaspin had no effect on proliferation of HUVEC which is an important process of the healing of the stented vessel. In addition, the occurrence of ISR after PCI with implantation of drug eluting stents was significantly associated with low vaspin plasma levels before intervention. Determination of vaspin plasma levels before PCI might be helpful in the identification of patients with high risk for development of ISR after stent implantation. In addition, the selective effects of vaspin on smooth muscle cell migration could potentially be used to reduce ISR without inhibition of re-endothelialization of the stented segment. ]]> <![CDATA[Development of a risk score for predicting the benefit versus harm of extending dual antiplatelet therapy beyond 6 months following percutaneous coronary intervention for stable coronary artery disease]]> https://www.researchpad.co/article/5c6f1498d5eed0c48467a3af

Background

Decisions on dual antiplatelet therapy (DAPT) duration should balance the opposing risks of ischaemia and bleeding. Our aim was to develop a risk score to identify stable coronary artery disease (SCAD) patients undergoing PCI who would benefit or suffer from extending DAPT beyond 6 months.

Methods

Retrospective analysis of a cohort of patients who completed 6 months of DAPT following PCI. Predictors of ischaemic and bleeding events for the 6–12 month period post-PCI were identified and a risk score was developed to estimate the likelihood of benefiting from extending DAPT beyond 6 months. Incidence of mortality, ischaemic and bleeding events for patients treated with DAPT for 6 vs. 6–12 months, was compared, stratified by strata of the risk score.

Results

The study included 2,699 patients. Over 6 months’ follow up, there were 78 (2.9%) ischaemic and 43 (1.6%) bleeding events. Four variables (heart failure, left ventricular ejection fraction ≤30%, left main or three vessel CAD, status post (s/p) PCI and s/p stroke) predicted ischemic events, two variables (age>75, haemoglobin <10 g/dL) predicted bleeding. In the lower stratum of the risk score, 6–12 months of treatment with DAPT resulted in increased bleeding (p = 0.045) with no decrease in ischaemic events. In the upper stratum, 6–12 months DAPT was associated with reduced ischaemic events (p = 0.029), with no increase in bleeding.

Conclusion

In a population of SCAD patients who completed 6 months of DAPT, a risk score for subsequent ischaemic and bleeding events identified patients likely to benefit from continuing or stopping DAPT.

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<![CDATA[The usefulness of wire-guided endoscopic snare papillectomy for tumors of the major duodenal papilla]]> https://www.researchpad.co/article/5c5217dfd5eed0c484794a8a

Objectives

Although endoscopic papillectomy is useful for treating papillary tumors, it is associated with a high rate of complications including pancreatitis; therefore, safer treatment options are needed. We examined the utility of wire-guided endoscopic papillectomy by comparing the pancreatic duct stenting and pancreatitis rates before and after wire-guided endoscopic papillectomy was introduced at our institution.

Methods

We retrospectively examined the data from 16 consecutive patients who underwent conventional endoscopic papillectomy between November 1995 and July 2005 and the data from 33 patients in whom wire-guided endoscopic papillectomy was first attempted at our institution between August 2005 and April 2017. We compared the pancreatic duct stenting and pancreatitis rates between the two groups.

Results

Of the 33 patients in whom wire-guided endoscopic papillectomy was first attempted, the procedure was completed in 21. Pancreatic duct stenting was possible in 30 of the 33 patients in whom wire-guided endoscopic papillectomy was attempted (91%), and this rate was significantly higher than that before the introduction of wire-guided endoscopic papillectomy (68.8%). The incidence of pancreatitis before the introduction of wire-guided endoscopic papillectomy was 12.5%, but after August 2005, the incidence was reduced by half to 6.1%, which includes those patients in whom wire-guided endoscopic papillectomy could not be completed.

Conclusions

Although wire-guided endoscopic papillectomy cannot be completed in some patients, we believe that this method shows some potential for reducing the total incidence of post-endoscopic papillectomy pancreatitis owing to more successful pancreatic duct stenting.

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<![CDATA[Comparisons of early vascular reactions in biodegradable and durable polymer-based drug-eluting stents in the porcine coronary artery]]> https://www.researchpad.co/article/5c40f823d5eed0c48438714e

Current drug-eluting stents have abluminal polymer coating; however, thrombus formation in these compared with that in uniformly coated stents remains controversial. We evaluated thrombus formation and early endothelialization after using abluminal biodegradable polymer-coated sirolimus- (BP-SES), and everolimus-eluting stents (BP-EES) versus a durable polymer-coated everolimus-eluting stent (DP-EES) in an in vivo setting. BP-SES, BP-EES, and DP-EES (n = 6 each) were implanted in coronary arteries of 12 mini-pigs that were then sacrificed after 7 and 10 days. Stents were stained with hematoxylin and eosin, and a combined Verhoeff and Masson trichrome stain. Areas of fibrin deposition were digitally detected and measured with off-line morphometric software. Stents were investigated for re-endothelialization by transmission electron microscopy. At 7 days, histological analysis revealed the lowest area of fibrin deposition in BP-SES (BP-SES vs. BP-EES vs. DP-EES; 0.10 ± 0.06 mm2 vs. 0.15 ± 0.07 mm2 vs. 0.19 ± 0.06 mm2, p = 0.0004). At 10 days, the area of fibrin deposition was significantly greater in DP-EES (0.13 ± 0.04 mm2 vs. 0.14 ± 0.05 mm2 vs. 0.19 ± 0.08 mm2, p = 0.007). Endothelial cells in BP-SES demonstrated a significantly greater number of tight junctions than those in DP-EES according to by transmission electron microscopy for both days (p<0.05). Various parameters, including an inflammatory reaction and neointimal formation, were comparable among the groups at 7 and 10 days. An abluminal biodegradable polymer-coated SES showed the least fibrin deposition and greatest endothelial cell recovery at an early stage following implantation in the coronary arteries of mini-pigs.

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<![CDATA[Competing risks of major bleeding and thrombotic events with prasugrel-based dual antiplatelet therapy after stent implantation - An observational analysis from BASKET-PROVE II]]> https://www.researchpad.co/article/5c478c6dd5eed0c484bd2457

Background

Dual antiplatelet therapy (DAPT) prevents thrombotic events after coronary stent implantation but may induce bleedings, specifically in elderly patients. However, a competitive risk analysis is lacking.

Objectives

To assess the determinants of major bleeding and the balance between the competing risks of major bleeding and thrombotic events during prasugrel-based DAPT after stent implantation.

Methods

Overall, 2,291 patients randomized to drug-eluting or bare metal stents and treated with prasugrel 10mg/day for 1 year were followed over 2 years for major bleeding (BARC 3/5) and thrombotic events (cardiac death, myocardial infarction, definitive/probable stent thrombosis). Prasugrel dose was reduced to 5mg in patients >75 years and/or <60kg. Predictors of major bleeding and competing risks of major bleeding and thrombotic events were assessed.

Results

Two-year rates of major bleeding and thrombotic events were 2.9% and 9.0%, respectively. The only independent predictor of major bleeding was age (hazard ratio per year increase 1.05 [1.02,1.07], p<0.001). The relationship between major bleeding and age was non-linear, with lowest hazard ratios at 57 years and an exponential increase only above 65 years. In contrast, the relationship between thrombotic events and age was linear and continuously increasing with older age. While the competing risk of thrombotic events was higher than that of major bleeding in younger patients, the two risks were similar in older patients. After discontinuation of prasugrel, bleeding events leveled off in all patients, while thrombotic events continued to increase.

Conclusions

In prasugrel-based DAPT, age is the strongest risk factor for major bleeding, increasing exponentially >65 years. In younger patients, thrombotic events represent a higher risk than bleeding, while thrombotic and bleeding risks were similar in older patients. Important clinical implications relate to prasugrel dose in the elderly, duration of DAPT and the competing risk balance necessitating individualized treatment decisions.

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<![CDATA[Relationship between the extent of aortic replacement and stent graft for acute DeBakey type I aortic dissection and outcomes: Results from a medical center in Taiwan]]> https://www.researchpad.co/article/5c390bbcd5eed0c48491e113

Background

Total arch replacement (TAR) and/or stent graft implantation has been proposed as the primary surgical treatment for acute DeBakey type I aortic dissection. However, the suggestion was based on excellent outcomes of high-volume or aortic centers. How about the real results in most places around the world? The purpose of this study was intended to compared in-hospital mortality, major complications, and aortic remodeling between TAR and/or stent graft implantation in a medical center of northern Taiwan.

Methods

Between January 2008 and August 2017, 156 patients with acute type I aortic dissection underwent surgery at our institution, including proximal aortic replacement only (Group I, n = 72), concomitant TAR (Group II, n = 23), concomitant TAR extended with stent grafting (Group III, n = 45), and proximal aortic replacement with descending aortic stent grafting (Group IV, n = 16).

Results

No significant differences were found in underlying disease and preoperative presentations, including operative risk among four groups. Overall in-hospital mortality was 22.4% (13 patients in Group I, 9 in Group II, 12 in Group III, and 1 in Group IV). New-onset stroke occurred in 15 patients postoperatively (3 patients [5.2%] in Group I, 3 [21.4%] in Group II, and 9 [26.5%] in Group III after excluding 36 patients with documented preoperative cerebrovascular accident or cerebral malperfusion). Root reconstruction and TAR were significantly associated with in-hospital mortality. TAR was significantly associated with surgery-related stroke. Compared to those in Group I, true lumen expansion and false lumen shrinkage during 1-year aortic remodeling were significantly higher in Groups III and IV. Both TAR and descending aorta stent grafting were significantly associated with decreased risk of patent false lumen.

Conclusions

Proximal aortic replacement remains the preferred surgical strategy for acute type I aortic dissection, with lower mortality and neurological complications. Proximal descending aorta stent grafting may benefit aortic remodeling, even without TAR.

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<![CDATA[Zn-alloy provides a novel platform for mechanically stable bioresorbable vascular stents]]> https://www.researchpad.co/article/5c3667f5d5eed0c4841a6b17

Metallic Zn alloys have recently gained interest as potential candidates for developing platforms of bioresorbable vascular stents (BVS). Previous studies revealed that Mg alloys used for BVS can degrade too early, whereas PLLA materials may fail to provide effective scaffolding properties. Here we report on results of a new bioresorbable, metallic stent made from a Zn-Ag alloy studied in a porcine animal model of thrombosis and restenosis. While the tensile strength (MPa) of Zn-3Ag was higher than that of PLLA and resembled Mg’s (WE43), fracture elongation (%) of Zn-3Ag was much greater (18-fold) than the PLLA’s or Mg alloy’s (WE43). Zn-3Ag exposed to HAoSMC culture medium for 30 days revealed degradation elements consisting of Zn, O, N, C, P, and Na at a 6 nm surface depth. Platelet adhesion rates and blood biocompatibility did not differ between Zn-3Ag, PLLA, Mg (WE43), and non-resorbable Nitinol (NiTi) stent materials. Balloon-expandable Zn-3Ag alloy BVS implanted into iliofemoral arteries of 15 juvenile domestic pigs were easily visible fluoroscopically at implantation, and their bioresorption was readily detectable via X-ray over time. Histologically, arteries with Zn-3Ag BVS were completely endothelialized, covered with neointima, and were patent at 1, 3, and 6 months follow-up with no signs of stent thrombosis. Zn-3Ag alloy appears to be a promising material platform for the fabrication of a new generation of bioresorbable vascular stents.

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<![CDATA[Relationship of body mass index and waist circumference with clinical outcomes following percutaneous coronary intervention]]> https://www.researchpad.co/article/5c1c0afad5eed0c484427095

Background

A biphasic, U-shape relationship has been reported between body mass index (BMI) and clinical outcomes following percutaneous coronary intervention (PCI). However, the relationship between waist circumference (WC) and the cardiovascular risk following PCI has not been reported.

Methods

A prospective cohort study was performed. A major adverse cardiac event (MACE) was defined as a composite of cardiac death (CD), nonfatal myocardial infarction (NFMI) and target vessel revascularization (TVR). Patients were evenly divided into 4 groups according to BMI (Q1BMI, Q2BMI, Q3BMI and Q4BMI) and WC (Q1WC, Q2WC, Q3WC and Q4WC).

Results

A total of 1,421 patients were observed for 5 years. The risk of the composite events of CD and NFMI (CD/NFMI) was lower in the Q3WC and Q4WC groups than in the Q1WC group, whereas it was only marginally lower in the Q2BMI group than in the Q1BMI group (ANOVA, p = 0.062). The risk of MACE was highest in the Q1WC group and lowest in the Q3WC group; however, the risk of MACE did not differ among the 4 groups, according to BMI. Multivariate Cox-regression analyses showed that the risk of CD/NFMI gradually decreased with BMI (linear p = 0.030) and with WC (linear p = 0.015). The risks of TVR and MACEs that were driven by TVRs showed a distinguishing biphasic, U-shaped relationship with WC (nonlinear p = 0.009) but not with BMI (nonlinear p = 0.439). Landmark survival analysis showed that the incidences of CD and NFMI were higher in the lower BMI groups and lower WC groups than in the higher BMI groups and higher WC groups, respectively, until 1 year and did not differ afterward. In contrast, the incidence of MACE was highest in Q1WC and lowest in Q3WC (log-rank p = 0.003), whereas the incidence was not different among the groups according to BMI.

Conclusions

Both BMI and WC were associated with a lower risk of early episodes of CD and NFMI after PCI. In the late period after PCI, WC demonstrated a biphasic, U-shaped association between cardiovascular outcomes and adiposity, whereas BMI did not.

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<![CDATA[Reproducibility of quantitative coronary computed tomography angiography in asymptomatic individuals and patients with acute chest pain]]> https://www.researchpad.co/article/5c1d5b59d5eed0c4846eb6cb

Purpose

Quantitative computed tomography (QCT) provides important prognostic information of coronary atherosclerosis. We investigated intraobserver and interobserver QCT reproducibility in asymptomatic individuals, patients with acute chest pain without acute coronary syndrome (ACS), and patients with acute chest pain and ACS.

Methods

Fifty patients from each cohort, scanned between 01/02/2010-14/11/2013 and matched according to age and gender, were retrospectively assessed for inclusion. Patients with no coronary artery disease, previous coronary artery bypass graft surgery, and poor image quality were excluded. Coronary atherosclerosis was measured semi-automatically by 2 readers. Reproducibility of minimal lumen area (MLA), minimal lumen diameter (MLD), area stenosis, diameter stenosis, vessel remodeling, plaque eccentricity, plaque burden, and plaque volumes was assessed using concordance correlation coefficient (CCC), Bland-Altman, coefficient of variation, and Cohen’s kappa.

Results

A total of 84 patients (63 matched) were included. Intraobserver and interobserver reproducibility estimates were acceptable for MLA (CCC = 0.94 and CCC = 0.91, respectively), MLD (CCC = 0.92 and CCC = 0.86, respectively), plaque burden (CCC = 0.86 and CCC = 0.80, respectively), and plaque volume (CCC = 0.97 and CCC = 0.95, respectively). QCT detected area and diameter stenosis ≥50%, positive remodeling, and eccentric plaque with moderate-good intraobserver and interobserver reproducibility (kappa: 0.64–0.66, 0.69–0.76, 0.46–0.48, and 0.41–0.62, respectively). Reproducibility of plaque composition decreased with decreasing plaque density (intraobserver and interobserver CCC for dense calcium (>0.99; 0.98), fibrotic (0.96; 0.93), fibro-fatty (0.95; 0.91), and necrotic core tissue (0.89; 0.84). Reproducibility generally decreased with worsening clinical risk profile.

Conclusions

Semi-automated QCT of coronary plaque morphology is reproducible, albeit with some decline in reproducibility with worsening patient risk profile.

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<![CDATA[Moderate-intensity versus high-intensity statin therapy in Korean patients with angina undergoing percutaneous coronary intervention with drug-eluting stents: A propensity-score matching analysis]]> https://www.researchpad.co/article/5c141f07d5eed0c484d2955a

Objectives

It is unclear whether high-intensity statin therapy provides incremental clinical benefits over moderate-intensity statin therapy in Asian patients with angina. This study sought to compare the clinical outcomes of moderate- and high-intensity statin therapies in patients undergoing percutaneous coronary intervention (PCI) for angina in Korean patients.

Methods

Based on the national health insurance claims data in South Korea, patients aged 18 years or older without a known history of coronary artery disease, who underwent PCI with drug-eluting stents due to angina between 2011 and 2015, were enrolled. According to the intensity of statin therapy, patients were categorized into moderate-intensity statin therapy (n = 23,863) and high-intensity statin therapy (n = 9,073) groups. The primary endpoint, defined as a composite of all-cause death and myocardial infarction, was compared between the two groups using a propensity-score matching analysis.

Results

During the follow-up period (median, 2.0 years; interquartile range, 1.1–3.1), 1,572 patients had 1,367 deaths and 242 myocardial infarctions. After propensity-score matching, there were 8,939 matched pairs. There was no significant difference in the incidence of the primary endpoint between the two groups (adjusted hazard ratio of high-intensity statin therapy, 1.093; 95% confidence interval: 0.950–1.259; p = 0.212).

Conclusions

In Korean patients undergoing PCI with drug-eluting stents for angina, the high-intensity statin therapy did not provide additional clinical benefits over the moderate-intensity statin therapy.

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<![CDATA[Anatomic measurements of cerebral venous sinuses in idiopathic intracranial hypertension patients]]> https://www.researchpad.co/article/5b28b404463d7e129299938f

Purpose

Magnetic resonance venography (MRV) has not been validated in pre-operative planning of the dural venous sinus stenting (VSS) among idiopathic intracranial hypertension (IIH) patients. We aim to prospectively evaluate dural venous sinus measurement in IIH patient population on two-dimensional time-of-flight (2D-TOF) MRV and Three-dimensional contrast-enhanced (3D-CE) MRV acquisitions and compare them against real-time endoluminal measurements with intravascular ultrasound (IVUS), served as the reference.

Materials and methods

The study has been approved by the Weill Cornell Medicine institutional review board. All patients signed written informed consent approved by IRB. Prospective evaluation of forty-five consecutive IIH patients treated with VSS at our institution were evaluated. Patients with pre-stent magnetic resonance venography (MRV) ≤ 6-months of VSS and intravascular ultrasound (IVUS) during VSS constituted the study population. Maximum diameter (in mm), Area (in cm2) and Perimeter (in cm) were measured at posterior 1/3rd of superior sagittal sinus (SSS), proximal transverse sinus (PTS), proximal sigmoid sinus (PSS) and mid sigmoid sinus (MSS) on 2D-TOF-MRV, 3D-CE-MRV and IVUS. Statistical analysis performed using box and whisker plots, Bland-Altman analysis and paired sample t-test.

Results

Twenty (n = 20) patients constituted our study population. The mean age was 30±11 years (7–59 years) and 18 out of 20 were female patients. Mean weight and BMI (range) were 86.3±18.3 kilograms (30.8–107.5 kgs) and 32.9±6.8 kg/M2 (16.4–48.3kg/M2) respectively. The CE-MRV significantly oversized the cerebral venous sinuses compared to TOF-MRV (Dmax: +2.0±1.35 mm, p<0.001; Area: +13.31±10.92 mm2, p<0.001 and Perimeter: +4.79±3.4 mm, p<0.001) and IVUS (Dmax: +1.52±2.16 mm, p<0.001; Area: +10.03±21.5 mm2, p<0.001 and Perimeter: +4.15±3.27 mm, p<0.001). The TOF-MRV sinus measurements were in good agreement with the IVUS measurements with no significant variation (Dmax: +.21±2.23 mm, p = 0.49; Area: +2.51±20.41mm2, p = 0.347 and Perimeter: +.001±1.11 mm, p = 0.991).

Conclusion

We report baseline cerebral venous sinus measurements (maximum diameter, area and perimeter) in patients with idiopathic intracranial hypertension. In our experience, TOF-MRV is a reliable representation of endoluminal cerebral venous sinus dimensions, and CE-MRV measurements reflected an overestimation of the endoluminal sinus dimensions when compared against the real time IVUS measurements.

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<![CDATA[Coronary Stent Artifact Reduction with an Edge-Enhancing Reconstruction Kernel – A Prospective Cross-Sectional Study with 256-Slice CT]]> https://www.researchpad.co/article/5989dac5ab0ee8fa60bb2272

Purpose

Metallic artifacts can result in an artificial thickening of the coronary stent wall which can significantly impair computed tomography (CT) imaging in patients with coronary stents. The objective of this study is to assess in vivo visualization of coronary stent wall and lumen with an edge-enhancing CT reconstruction kernel, as compared to a standard kernel.

Methods

This is a prospective cross-sectional study involving the assessment of 71 coronary stents (24 patients), with blinded observers. After 256-slice CT angiography, image reconstruction was done with medium-smooth and edge-enhancing kernels. Stent wall thickness was measured with both orthogonal and circumference methods, averaging thickness from diameter and circumference measurements, respectively. Image quality was assessed quantitatively using objective parameters (noise, signal to noise (SNR) and contrast to noise (CNR) ratios), as well as visually using a 5-point Likert scale.

Results

Stent wall thickness was decreased with the edge-enhancing kernel in comparison to the standard kernel, either with the orthogonal (0.97 ± 0.02 versus 1.09 ± 0.03 mm, respectively; p<0.001) or the circumference method (1.13 ± 0.02 versus 1.21 ± 0.02 mm, respectively; p = 0.001). The edge-enhancing kernel generated less overestimation from nominal thickness compared to the standard kernel, both with the orthogonal (0.89 ± 0.19 versus 1.00 ± 0.26 mm, respectively; p<0.001) and the circumference (1.06 ± 0.26 versus 1.13 ± 0.31 mm, respectively; p = 0.005) methods. The edge-enhancing kernel was associated with lower SNR and CNR, as well as higher background noise (all p < 0.001), in comparison to the medium-smooth kernel. Stent visual scores were higher with the edge-enhancing kernel (p<0.001).

Conclusion

In vivo 256-slice CT assessment of coronary stents shows that the edge-enhancing CT reconstruction kernel generates thinner stent walls, less overestimation from nominal thickness, and better image quality scores than the standard kernel.

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<![CDATA[Treatment of Middle Ear Ventilation Disorders: Sheep as Animal Model for Stenting the Human Eustachian Tube – A Cadaver Study]]> https://www.researchpad.co/article/5989daebab0ee8fa60bbf257

Eustachian tube disorders can lead to chronic otitis media with consecutive conductive hearing loss. To improve treatment and to develop new types of implants such as stents, an adequate experimental animal model is required. As the middle ear of sheep is known to be comparable to the human middle ear, the dimensions of the Eustachian tube in two strains of sheep were investigated. The Eustachian tube and middle ear of half heads of heathland and blackface sheep were filled with silicone rubber, blended with barium sulfate to induce X-ray visibility. Images were taken by digital volume tomography. The tubes were segmented, and a three-dimensional model of every Eustachian tube was generated. The lengths, diameters and shapes were determined. Additionally, the feasibility of endoscopic stent implantation and fixation was tested in cadaver experiments. The length of the tube between ostium pharyngeum and the isthmus and the diameters were comparable to published values for the human tube. The tube was easily accessible through the nose, and then stents could be implanted and fixed at the isthmus. The sheep appears to be a promising model for testing new stent treatments for middle ear ventilation disorders.

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<![CDATA[Use of a Heart Team in Decision-Making for Patients with Complex Coronary Disease at Hospitals in Michigan Prior to Guideline Endorsement]]> https://www.researchpad.co/article/5989da42ab0ee8fa60b8a6c8

Background

Revascularization decisions can profoundly impact patient survival, quality of life, and procedural risk. Although use of Heart Teams to make revascularization decisions is growing, data on their implementation in the real-world are limited. Our objective was to assess the prevalence of Heart Teams and their association with collaboration in routine practice.

Methods

A survey of cardiologists and cardiac surgeons at 31 hospitals in Michigan was performed in May, 2011 – prior to the recommendation for using Heart Teams in national guidelines. This survey included all percutaneous coronary intervention-performing hospitals in Michigan participating in the Blue Cross/Blue Shield of Michigan Cardiovascular Consortium and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative. It targeted both the use of Heart Teams and multidisciplinary Case Conferences.

Results

There were 53 physician survey respondents from 27 hospitals with 4 hospitals not responding. Among respondents, 11 (40.7%) hospitals reported no Heart Teams or Case Conferences while 7 (25.9%) hospitals reported either a Heart Team or Case Conference. However, there was disagreement about the presence of a Heart Team at seven hospitals, and about Case Conferences at nine hospitals. Hospitals with definite Heart Teams reported significantly greater levels of collaboration between cardiologists and cardiac surgeons.

Conclusion

The overall presence of Heart Teams prior to their recommendation in national guidelines was limited. Even among hospitals with a potential Heart Team, there was substantial disagreement between respondents about their presence. Further refinement of the definition of a Heart Team and measures of successful implementation are needed.

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<![CDATA[Prevention of neointimal formation using miRNA-126-containing nanoparticle-conjugated stents in a rabbit model]]> https://www.researchpad.co/article/5989db52ab0ee8fa60bdc749

Background

Despite recent progress with drug-eluting stents, restenosis and thrombosis after endovascular intervention are still major limitations in the treatment of cardiovascular diseases. These problems are possibly caused by inappropriate inhibition of neointimal formation and retardation of re-endothelialization on the surface of the stents. miR-126 has been shown to have the potential to enhance vascular endothelial cell proliferation.

Methods and results

We designed and constructed a 27-nt double strand RNA (dsRNA) conjugated to cholesterol, which has high membrane permeability, and formed mature miR-126 after transfection. For site-specific induction of miR-126, we utilized poly (DL-lactide-co-glycolide) nanoparticles (NPs). miR-126-dsRNA-containing NPs (miR-126 NPs) significantly reduced the protein expression of a previously identified miR-126 target, SPRED1, in human umbilical vascular endothelial cells (HUVECs), and miR-126 NPs enhanced the proliferation and migration of HUVECs. On the other hand, miR-126 NPs reduced the proliferation and migration of vascular smooth muscle cells, via the suppression of IRS-1. Finally, we developed a stent system that eluted miR-126. This delivery system exhibited significant inhibition of neointimal formation in a rabbit model of restenosis.

Conclusions

miR-126 NP-conjugated stents significantly inhibited the development of neointimal hyperplasia in rabbits. The present study may indicate the possibility of a novel therapeutic option to prevent restenosis after angioplasty.

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<![CDATA[Duration of dual antiplatelet therapy in patients treated with percutaneous coronary intervention for coronary chronic total occlusion]]> https://www.researchpad.co/article/5989db5aab0ee8fa60bdf52b

Background

The duration of dual antiplatelet therapy (DAPT) after drug-eluting stent implantation in coronary chronic total occlusion (CTO) remains unclear.

Methods

We retrospectively analyzed a total of 512 patients treated with percutaneous coronary intervention (PCI) in the Samsung Medical Center CTO registry. Patients were separated into ≤ 12-month (199, 38.9%) vs. > 12 month (313, 61.1%) based on DAPT duration with aspirin and clopidogrel. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE) during follow-up.

Results

Median follow-up duration was 67 (interquartile range: 51–84) months. MACCE occurred in 43 patients (21.6%) in the ≤ 12-month and 55 patients (17.6%) in the > 12-month groups. In the propensity-matched population, the rate of MACCE did not differ significantly between the ≤ 12-month and > 12-month group (19.4% vs. 18.8%; hazard ratio [HR], 0.95; 95% confidential interval [CI], 0.52–1.76, p = 0.88). Moreover, moderate or severe bleeding according to BARC criteria (type 2, 3 or 5) was also similar between the ≤ 12-month and > 12-month group (2.5% vs. 1.9%; HR, 1.00; 95% CI, 0.20–4.96, p = 0.99).

Conclusion

Among patients treated with PCI for CTO, DAPT with durations of ≤ 12-month showed similar long-term clinical outcomes compared to > 12-month DAPT.

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<![CDATA[Endovascular stentectomy using the snare over stent-retriever (SOS) technique: An experimental feasibility study]]> https://www.researchpad.co/article/5989db5cab0ee8fa60be001d

Feasibility of endovascular stentectomy using a snare over stent-retriever (SOS) technique was evaluated in a silicon flow model and an in vivo swine model. In vitro, stentectomy of different intracranial stents using the SOS technique was feasible in 22 out of 24 (92%) retrieval maneuvers. In vivo, stentectomy was successful in 10 out of 10 procedures (100%). In one case self-limiting vasospasm was observed angiographically as a technique related complication in the animal model. Endovascular stentectomy using the SOS technique is feasible in an experimental setting and may be transferred to a clinical scenario.

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<![CDATA[Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice]]> https://www.researchpad.co/article/5989d9efab0ee8fa60b6e02a

Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.

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<![CDATA[Assessment of Inter-Expert Variability and of an Automated Segmentation Method of 40 and 60 MHz IVUS Images of Coronary Arteries]]> https://www.researchpad.co/article/5989db53ab0ee8fa60bdcee1

The objectives were to compare the performance of a segmentation algorithm, based on the minimization of an uncertainty function, to delineate contours of external elastic membrane and lumen of human coronary arteries imaged with 40 and 60 MHz IVUS, and to use values of this function to delineate portions of contours with highest uncertainty. For 8 patients, 40 and 60 MHz IVUS coronary data acquired pre- and post-interventions were used, for a total of 68,516 images. Manual segmentations of contours (on 2312 images) performed by experts at three core laboratories were the gold-standards. Inter-expert variability was highest on contour points with largest values of the uncertainty function (p < 0.001). Inter-expert variability was lower at 60 than 40 MHz for external elastic membrane (p = 0.013) and lumen (p = 0.024). Average differences in plaque (and atheroma) burden between algorithmic contours and experts’ contours were within inter-expert variability (p < 0.001).

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<![CDATA[Large Residual Volume, Not Low Packing Density, Is the Most Influential Risk Factor for Recanalization after Coil Embolization of Cerebral Aneurysms]]> https://www.researchpad.co/article/5989da62ab0ee8fa60b912f4

Background

Tight coil packing with density of at least 20%–25% is known to be important for preventing recanalization after embolization of cerebral aneurysms. However, large aneurysms sometimes recanalize regardless of the packing density, suggesting that the absolute residual volume which is determined by aneurysm volume and packing density may be more important risk factor for recanalization. To validate this hypothesis, we analyzed the factors affecting the outcomes of treated aneurysms at our institute.

Methods and Findings

We included 355 small and large aneurysms. The following six factors were obtained from every case: aneurysm volume (mL), neck size (mm), packing density (%), residual volume (mL), rupture status at presentation, and stent assistance (with or without stent). The data were then subjected to multivariate logistic regression analysis to identify significant risk factors for recanalization. Recanalization occurred in 61 aneurysms (17.2%). Significant predictors for recanalization were aneurysm volume (odds ratio, 15.3; P < 0.001) and residual volume (odds ratio, 30.9; P < 0.001), but not packing density (odds ratio, 0.98; P = 0.341). These results showed that for each 0.1-mL increase in aneurysm volume and residual volume, the risk of recanalization increased by 1.3 times and 1.4 times, respectively.

Conclusions

The most influential risk factor for recanalization after coil embolization was residual volume, not packing density. The larger the aneurysm volume, the greater the packing density has to be to minimize the residual volume and risk of recanalization. Since tight coil packing has already been aimed, further innovation of coil property or embolization technique may be needed. Otherwise, different treatment modality such as flow diverter or parent artery occlusion may have to be considered.

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