ResearchPad - coronary-stenting 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[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[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[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[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[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[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[The Ratio of ADP- to TRAP-Induced Platelet Aggregation Quantifies P2Y12-Dependent Platelet Inhibition Independently of the Platelet Count]]> https://www.researchpad.co/article/5989db39ab0ee8fa60bd42e1

Objective

This study aimed to assess the association of clinical factors with P2Y12-dependent platelet inhibition as monitored by the ratio of ADP- to TRAP-induced platelet aggregation and conventional ADP-induced aggregation, respectively.

Background

Controversial findings to identify and overcome high platelet reactivity (HPR) after coronary stent-implantation and to improve clinical outcome by tailored anti-platelet therapy exist. Monitoring anti-platelet therapy ex vivo underlies several confounding parameters causing that ex vivo platelet aggregation might not reflect in vivo platelet inhibition.

Methods

In a single centre observational study, multiple electrode aggregometry was performed in whole blood of patients after recent coronary stent-implantation. Relative ADP-induced aggregation (r-ADP-agg) was defined as the ratio of ADP- to TRAP- induced aggregation reflecting the individual degree of P2Y12-mediated platelet reactivity.

Results

Platelet aggregation was assessed in 359 patients. Means (± SD) of TRAP-, ADP-induced aggregation and r-ADP-agg were 794 ± 239 AU*min, 297 ± 153 AU*min and 37 ± 14%, respectively. While ADP- and TRAP-induced platelet aggregation correlated significantly with platelet count (ADP: r = 0.302; p<0.001; TRAP: r = 0.509 p<0.001), r-ADP-agg values did not (r = -0.003; p = 0.960). These findings were unaltered in multivariate analyses adjusting for a range of factors potentially influencing platelet aggregation. The presence of an acute coronary syndrome and body weight were found to correlate with both ADP-induced platelet aggregation and r-ADP-agg.

Conclusion

The ratio of ADP- to TRAP-induced platelet aggregation quantifies P2Y12-dependent platelet inhibition independently of the platelet count in contrast to conventional ADP-induced aggregation. Furthermore, r-ADP-agg was associated with the presence of an acute coronary syndrome and body weight as well as ADP-induced aggregation. Thus, the r-ADP-agg is a more valid reflecting platelet aggregation and potentially prognosis after coronary stent-implantation in P2Y12-mediated HPR than conventional ADP-induced platelet aggregation.

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<![CDATA[Imaging of pediatric great vessel stents: Computed tomography or magnetic resonance imaging?]]> https://www.researchpad.co/article/5989db53ab0ee8fa60bdcc14

Background

Complications might occur after great vessel stent implantation in children. Therefore follow-up using imaging is warranted.

Purpose

To determine the optimal imaging modality for the assessment of stents used to treat great vessel obstructions in children.

Material and methods

Five different large vessel stents were evaluated in an in-vitro setting. All stents were expanded to the maximal vendor recommended diameter (20mm; n = 4 or 10mm; n = 1), placed in an anthropomorphic chest phantom and imaged with a 256-slice CT-scanner. MRI images were acquired at 1.5T using a multi-slice T2-weighted turbo spin echo, an RF-spoiled three-dimensional T1-weighted Fast Field Echo and a balanced turbo field echo 3D sequence. Two blinded observers assessed stent lumen visibility (measured diameter/true diameter *100%) in the center and at the outlets of the stent. Reproducibility of diameter measurements was evaluated using the intraclass correlation coefficient for reliability and 95% limits of agreement for agreement analysis.

Results

Median stent lumen visibility was 88 (IQR 86–90)% with CT for all stents at both the center and outlets. With MRI, the T2-weighted turbo spin echo sequence was preferred which resulted in 82 (78–84%) stent lumen visibility. Interobserver reliability and agreement was good for both CT (ICC 0.997, mean difference -0.51 [-1.07–0.05] mm) and MRI measurements (ICC 0.951, mean difference -0.05 [-2.52 –-2.41] mm).

Conclusion

Good in-stent lumen visibility was achievable in this in-vitro study with both CT and MRI in different great vessel stents. Overall reliability was good with clinical acceptable limits of agreement for both CT and MRI. However, common conditions such as in-stent stenosis and associated aneurysms were not tested in this in-vitro study, limiting the value of the in-vitro study.

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<![CDATA[A Novel Tram Stent Method in the Treatment of Coronary Bifurcation Lesions – Finite Element Study]]> https://www.researchpad.co/article/5989d9ecab0ee8fa60b6cd19

A novel stent was designed for the treatment of coronary bifurcation lesion, and it was investigated for its performance by finite element analysis. This study was performed in search of a novel method of treatment of bifurcation lesion with provisional stenting. A bifurcation model was created with the proximal vessel of 3.2 mm diameter, and the distal vessel after the side branch (2.3 mm) was 2.7 mm. A novel stent was designed with connection links that had a profile of a tram. Laser cutting and shape setting of the stent was performed, and thereafter it was crimped and deployed over a balloon. The contact pressure, stresses on the arterial wall, stresses on the stent, the maximal principal log strain of the main artery and the side-branch were studied. The study was performed in Abaqus, Simulia. The stresses on the main branch and the distal branch were minimally increased after deployment of this novel stent. The side branch was preserved, and the stresses on the side branch were lesser; and at the confluence of bifurcation on either side of the side branch origin the von-Mises stress was marginally increased. The stresses and strain at the bifurcation were significantly lesser than the stresses and strain of the currently existing techniques used in the treatment of bifurcation lesions though the study was primarily focused only on the utility of the new technology. There is a potential for a novel Tram-stent method in the treatment of coronary bifurcation lesions.

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<![CDATA[Staged versus One-Time Complete Revascularization with Percutaneous Coronary Intervention in STEMI Patients with Multivessel Disease: A Systematic Review and Meta-Analysis]]> https://www.researchpad.co/article/5989db53ab0ee8fa60bdcec6

Introduction

In patients with acute ST-elevation myocardial infarction (STEMI), the preferred intervention is percutaneous coronary intervention (PCI).Whether staged PCI (S-PCI) or one-time complete PCI (MV-PCI) is more beneficial and safer in terms of treating the non-culprit vessel during the primary PCI procedure is unclear. We performed a meta-analysis of all randomized and non-randomized controlled trials comparing S-PCI with MV-PCI in patients with acute STEMI and MVD.

Methods

Studies of STEMI with multivessel disease receiving primary PCI were searched in PUBMED, EMBASE and The Cochrane Register of Controlled Trials from January 2004 to December 2014. The primary end points were long-term rates of major adverse cardiovascular events and their components—mortality, reinfarction, and target-vessel revascularization. Data were combined using a fixed-effects model.

Results

Of 507 citations, 10 studies (4 randomized, 6 nonrandomized; 820 patients, 562 staged PCI and 347 one-time, complete multi-vessel PCI) were included. S-PCI compared to MV-PCI significantly reduced mortality both long-term (OR 0.44, 95% CI 0.29–0.66, P<0.0001, I2 = 0%) and short-term (OR 0.23, 95% CI 0.1–0.51, P = 0.0003, I2 = 0%). There was a trend toward reduced risk of MACE with s-PCI compared with MV-PCI (OR 0.83, 0.62–1.12, P = 0.22, I2 = 0%). No difference between S-PCI and MV-PCI was observed in reinfarction (OR 0.97, 0.61–1.55, P = 0.91, I2 = 0%), or target vessel revascularization (OR1.17, 95% CI 0.81–1.69, P = 0.40, I2 = 8%).

Conclusions

The staged strategy for non-culprit lesions improved short- and long-term survival and should remain the standard approach to primary PCI in patients with STEMI; one-time complete multivessel PCI may be associated with greater mortality risk. However, additional large, randomized trials are required to confirm the optimal timing of a staged procedure on the non-culprit vessel in STEMI.

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<![CDATA[A Novel Attempt to Standardize Results of CFD Simulations Basing on Spatial Configuration of Aortic Stent-Grafts]]> https://www.researchpad.co/article/5989d9feab0ee8fa60b733d0

Currently, studies connected with Computational Fluid Dynamic (CFD) techniques focus on assessing hemodynamic of blood flow in vessels in different conditions e.g. after stent-graft’s placement. The paper propose a novel method of standardization of results obtained from calculations of stent-grafts' “pushing forces” (cumulative WSS—Wall Shear Stress), and describes its usefulness in diagnostic process. AngioCT data from 27 patients were used to reconstruct 3D geometries of stent-grafts which next were used to create respective reference cylinders. We made an assumption that both the side surface and the height of a stent-graft and a reference cylinder were equal. The proposed algorithm in conjunction with a stent-graft “pushing forces” on an implant wall, allowed us to determine which spatial configuration of a stent-graft predispose to the higher risk of its migration. For stent-grafts close to cylindrical shape (shape factor φ close to 1) WSS value was about 267Pa, while for stent-grafts different from cylindrical shape (φ close to 2) WSS value was about 635Pa. It was also noticed that deformation in the stent-graft’s bifurcation part impaired blood flow hemodynamic. Concluding the proposed algorithm of standardization proved its usefulness in estimating the WSS values that may be useful in diagnostic process. Angular bends or tortuosity in bifurcations of an aortic implant should be considered in further studies of estimation of the risk of implantation failure.

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<![CDATA[Can Platforms Affect the Safety and Efficacy of Drug-Eluting Stents in the Era of Biodegradable Polymers?: A Meta-Analysis of 34,850 Randomized Individuals]]> https://www.researchpad.co/article/5989dac0ab0ee8fa60bb06f1

Objective

In the era of bare metal stents (BMSs), alloys have been considered to be better materials for stent design than stainless steel. In the era of biodegradable polymer drug-eluting stents (BP-DESs), the safety and efficacy of BP-DESs with different metal platforms (stainless steel or alloys) have not yet been reported, although their polymers are eventually absorbed, and only the metal platforms remain in the body. This study sought to determine the clinical safety and efficacy of BP-DESs with different platforms compared with other stents (other DESs and BMSs).

Methods

PubMed, Embase and Clinical Trials.gov were searched for randomized controlled trials (RCTs) that compared BP-DESs with other stents. After performing pooled analysis of BP-DESs and other stents, we performed a subgroup analysis using two classification methods: stent platform and follow-up time. The study characteristics, patient characteristics and clinical outcomes were abstracted.

Results

Forty RCTs (49 studies) comprising 34,850 patients were included. Biodegradable polymer stainless drug-eluting stents (BP-stainless DESs) were superior to the other stents [mainly stainless drug-eluting stents (DESs)] in terms of pooled definite/probable stent thrombosis (ST) (OR [95% CI] = 0.76[0.61–0.95], p = 0.02), long-term definite/probable ST (OR [95% CI] = 0.73[0.57–0.94], p = 0.01), very late definite/probable ST (OR [95% CI] = 0.56[0.33–0.93], p = 0.03) and long-term definite ST. BP-stainless DESs had lower rates of pooled, mid-term and long-term target vessel revascularization (TVR) and target lesion revascularization (TLR) than the other stainless DESs and BMSs. Furthermore, BP-stainless DESs were associated with lower rates of long-term death than other stainless DESs and lower rates of mid-term myocardial infarction than BMSs. However, only the mid-term and long-term TVR rates were superior in BP-alloy DESs compared with the other stents.

Conclusion

Our results indirectly suggest that BP-stainless DESs may offer more benefits than BP-alloy DESs in the era of BP-DESs. Further well-designed RCTs comparing BP-stainless with BP-alloy DESs are needed to confirm which platform is better.

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<![CDATA[Antiplatelet Therapy of Cilostazol or Sarpogrelate with Aspirin and Clopidogrel after Percutaneous Coronary Intervention: A Retrospective Cohort Study Using the Korean National Health Insurance Claim Database]]> https://www.researchpad.co/article/5989d9e7ab0ee8fa60b6b7ef

Background/Objectives

Addition of cilostazol or sarpogrelate to the standard dual antiplatelet therapy of aspirin and clopidogrel has been implemented in patients that underwent percutaneous coronary intervention (PCI) with stents in Korea. This study aimed to evaluate the efficacy and safety of triple antiplatelet therapies.

Methods

This retrospective cohort study was performed using the Korean National Insurance Claim Data of the Health Insurance Review and Assessment Service from January 1, 2009 to December 31, 2014. The study cohort population consisted of patients with ischemic heart diseases and a history of PCI. They were treated with antiplatelet therapy of aspirin, clopidogrel (AC); aspirin, clopidogrel, cilostazol (ACCi); or aspirin, clopidogrel, sarpogrelate (ACSa) during the index period from January 1, 2010 to December 31, 2011. During the follow-up period up to December 31, 2014, the major adverse cardiac or cerebral events (MACCE) including death, myocardial infarction, target lesion revascularization, and ischemic stroke were assessed. Bleeding complications were also evaluated as adverse drug events.

Results

Out of 93,876 patients with PCI during the index period, 69,491 patients started dual (AC) or triple therapy (ACSa or ACCi). The clinical outcomes of comparing ACSa and ACCi therapy showed beneficial effects in the ACSa group in the prevention of subsequent cardiac or cerebral events. After Propensity score-matching between ACSa and ACCi groups, there were significant differences in MI and revascularization, with corresponding HR of 0.38 (95% CI, 0.20–0.73) and 0.66 (95% CI, 0.53–0.82) in ACSa vs. ACCi at 12 months, respectively. At the 24-month follow-up, the triple therapy groups (ACS or ACC) had a higher incidence of MACCE compared to the dual therapy (AC) group; ACSa vs. AC HR of 1.69 (95% CI, 1.62–1.77); ACC vs. AC HR of 1.22 (95% CI, 1.06–1.41). There was no significant difference in severe or life-threatening bleeding risk among three groups; ACSa vs. AC, HR of 0.68 (95% CI, 0.37–1.24), ACCi vs. AC, HR of 0.91 (95% CI, 0.77–1.09).

Conclusion

Sarpogrelate-containing triple antiplatelet therapy demonstrated comparable rates of MACCE prevention to the conventional dual antiplatelet therapy after PCI without significantly increasing bleeding risk during the two-year follow-up period.

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<![CDATA[Association of the Endothelial Nitric Oxide Synthase Gene T786C Polymorphism with In-Stent Restenosis in Chinese Han Patients with Coronary Artery Disease Treated with Drug-Eluting Stent]]> https://www.researchpad.co/article/5989db52ab0ee8fa60bdc99d

Background and aim

Many studies have reported that genetic variants correlate with higher risk for coronary artery disease (CAD) or in-stent restenosis (ISR) after bare metal stent (BMS) implantation. However, there is limited data assessing the impact of these variants on ISR in patients treated with drug-eluting stent (DES). The purpose of this study was to investigate the effects of genetic risk factors on ISR in Chinese Han patients treated with DES.

Methods

A total of 425 patients with a diagnosis of CAD who underwent successful revascularization in native coronary arteries with DES were included in this retrospective study. Genotyping was performed on six single nucleotide polymorphisms (SNPs) in the endothelial nitric oxide synthase gene (eNOS), the angiotensin converting enzyme gene (ACE), the angiotensin II type 1 receptor gene (AT1R), the transforming growth factor beta gene (TGF-β), and the vascular endothelial growth factor gene (VEGF). Quantitative coronary angiography (QCA) was performed during the follow-up period to detect ISR. Logistic regression models were used to test for association.

Results

Fifty-four patients (12.7%) developed ISR during the follow-up period. Of the six analyzed SNPs, the frequency of the C allele of T786C polymorphism in eNOS was significantly higher in the ISR group (22.2%) compared to the non-ISR group (12.7%) (p<0.01). In the ISR group, the frequency of the TT, TC, and CC genotypes was 61.1%, 33.3%, and 5.6%, respectively, and in the non-ISR group, the frequencies were 76.8%, 21.0%, and 2.2%, respectively. The multivariable analysis adjusted for potential confounders and revealed that the T786C polymorphism increased the risk of ISR in both additive and dominant models with odds ratios of 1.870 (95% confidence interval [CI]: 1.079–3.240, p = 0.03) and 2.045 (95% CI: 1.056–3.958, p = 0.03), respectively.

Conclusion

The eNOS T786C polymorphism was associated with ISR in Chinese Han patients treated with DES. Genotyping may be helpful to identify patients with higher risks of ISR after DES implantation.

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