Bare Metal Stents Group Research Articles

Ultrasound-guided direct intrahepatic portosystemic shunt in patients with Budd–Chiari syndrome: Short- and long-term results

Background and aims Budd–Chiari syndrome (BCS) is treated with anticoagulation therapy, transjugular intrahepatic portosystemic shunt (TIPS), angioplasty, and liver transplantation. TIPS is not always technically feasible, due to the complete hepatic venous thrombosis. Direct intrahepatic portosystemic shunt (DIPS) is an alternative method for decompression of portal hypertension. This is a retrospective, single-center study aiming to evaluate the outcome of ultrasound (US)-guided DIPS in patients with BCS. Materials and methods Between 2003 and 2016, six patients with BCS were treated with US-guided DIPS. Polytetrafluoroethylene (PTFE)-covered stents were used in two patients and bare-metal stents in four patients. Mean follow-up time was 71.4 months (range: 21–164). Technical/clinical success, technical difficulties, and complications of DIPS were analyzed. Results Technical success without complications was achieved in all patients (100%). In one patient, DIPS was performed through the right femoral vein, without significant amelioration of portal hypertension (clinical success 83.3%). In four out of five patients, ascites and variceal bleeding resolved completely and in the other one ascites was relieved. Six- and 12-month primary patency rates were 100% in PTFE-covered stent group when compared with bare-metal stent group, the rates were 33% and 0%, respectively. Conclusion US-guided DIPS is a safe and effective alternative technique for patients with BCS, with significant clinical improvement.

Evaluation of ion implantation for anti-thrombogenic coronary stent in vitro and in vivo

Abstract The aim of this study was to evaluate the effect of ion implantation on the surface of anti-thrombogenic coronary stent. Nitrogen (N) was implanted into the cobalt–chromium surface by using an ion source under a plasma environment to enhance its hardness and surface modification. The N ion dosage was 1 × 1015 ions/cm2. All analysis results of the ion implanted stent were compared with those of bare metal stent. The N component and distribution were confirmed by auger electron spectroscopy. Microhardness was significantly increased after 40 min of implantation (415.3 ± 12.38 HV, 18.9 ± 2.62%). The surface was altered to hydrophobic status through ion implantation (30.6 ± 1.12% in contact angle increment). Platelet adhesion, and smooth muscle cell migration and proliferation were prevented in the ion implanted group (43.9%, 11.2%, and 45.1%, respectively). To verify the in vitro result, stents were implanted to rabbit iliac artery and isolated at 4 weeks post implantation. Then, the stents were subjected to histological analysis. No significant differences in injury score, internal elastic lamina, lumen area, and restenosis rate were found. However, the fibrin score was more significantly decreased in the ion beam-implanted group (2.5 ± 0.15) than in the bare metal stent group (1.8 ± 0.31, n = 10, p

Ultrasound-guided direct intrahepatic portosystemic shunt in patients with Budd-Chiari syndrome: Short- and long-term results.

Background and aimsBudd–Chiari syndrome (BCS) is treated with anticoagulation therapy, transjugular intrahepatic portosystemic shunt (TIPS), angioplasty, and liver transplantation. TIPS is not always technically feasible, due to the complete hepatic venous thrombosis. Direct intrahepatic portosystemic shunt (DIPS) is an alternative method for decompression of portal hypertension. This is a retrospective, single-center study aiming to evaluate the outcome of ultrasound (US)-guided DIPS in patients with BCS.Materials and methodsBetween 2003 and 2016, six patients with BCS were treated with US-guided DIPS. Polytetrafluoroethylene (PTFE)-covered stents were used in two patients and bare-metal stents in four patients. Mean follow-up time was 71.4 months (range: 21–164). Technical/clinical success, technical difficulties, and complications of DIPS were analyzed.ResultsTechnical success without complications was achieved in all patients (100%). In one patient, DIPS was performed through the right femoral vein, without significant amelioration of portal hypertension (clinical success 83.3%). In four out of five patients, ascites and variceal bleeding resolved completely and in the other one ascites was relieved. Six- and 12-month primary patency rates were 100% in PTFE-covered stent group when compared with bare-metal stent group, the rates were 33% and 0%, respectively.ConclusionUS-guided DIPS is a safe and effective alternative technique for patients with BCS, with significant clinical improvement.

Intravascular ultrasound assessment of minimum lumen area and intimal hyperplasia in in-stent restenosis after drug-eluting or bare-metal stent implantation. The Nordic Intravascular Ultrasound Study (NIVUS).

Drug-eluting stents (DES) reduce the risk of restenosis after percutaneous coronary intervention. The aim of the study was to evaluate, by intravascular ultrasound (IVUS), the minimum lumen area site in the stented segment and the distribution of intimal hyperplasia in patients presenting with a DES or bare-metal stent (BMS) in-stent restenosis. The "Nordic Intravascular Ultrasound Study (NIVUS)" study was conducted in Nordic and Baltic countries as a prospective multicenter registry. Two hundred nine patients (DES n=121 and BMS n=88) with in-stent restenosis were enrolled. At the minimum lumen area site in the stented segment, the stent area (5.8±2.2mm2 vs. 7.6±2.4mm2, p<0.001) and intimal hyperplasia area (2.6±2.0mm2 vs. 5.0±2.2mm2, p<0.001) were significantly lower in patients treated with DES compared to BMS. The percentage of stents that did not have a minimum stent area of at least 5.0mm2 (under expansion) was higher in DES (58.7% vs. 37.7%, p=0.008) compared to BMS. Intimal hyperplasia covered 55.4±33.3% of the stent length in the DES compared to 90.7±17.4% in the BMS group, p<0.001. Focal in-stent restenosis was more often seen in DES treated patients compared to BMS treated patients (DES n=84 (59.9%) vs. BMS n=15 (17.0%), p<0.001). Stent underexpansion was more often seen in DES than BMS in-stent restenosis. DES more often had focal in-stent restenosis with less intimal hyperplasia.

A Quantitative Angiographic Comparison of Restenotic Tissue Following Placement of Drug-Eluting Stents and Bare Metal Stents in Symptomatic Patients With Femoropopliteal Disease

Purpose: To evaluate the patterns of in-stent restenosis (ISR) within femoropopliteal bare metal stents (BMS) and drug-eluting stents (DES) as determined by quantitative angiographic analysis. Methods: Utilizing results from independent core laboratory angiographic imaging analysis, quantitative assessment of the restenotic tissue burden was evaluated in 33 patients with symptomatic femoropopliteal ISR, including 20 lesions in 19 patients (mean age 71.5±8.1 years; 11 men) treated with DES and 14 lesions in 14 patients (mean age 70.6±9.2 years; 9 men) treated with BMS. Results: The average time to target lesion revascularization was similar (8.7 months) for the DES and BMS groups. The DES group had significantly less recurrent disease burden (17.1%) compared with the BMS group (27.8%, p=0.03), representing a 39% relative reduction. Conclusion: Reduced restenotic tissue after endovascular intervention is associated with improved hemodynamics and fewer clinical symptoms and may explain the reduced need for reintervention in restenotic lesions initially treated with DES as compared with BMS. Further study of treatment failure modes may lead to improved device selection criteria to treat patients with peripheral artery disease.

Biological effect of microengineered grooved stents on strut healing: a randomised OCT-based comparative study in humans

ObjectiveTo evaluate the biological effect of microengineered stent grooves (MSG) on early strut healing in humans by performing optical coherence tomography (OCT) analysis 3 weeks following the implantation.BackgroundIn the experimental...

Sirolimus coating on heparinized stents prevents restenosis and thrombosis.

The aim of this study was to evaluate the inhibitory effect of sirolimus coating on the occurrence of restenosis and thrombosis with heparinized stents. Heparin and dopamine were conjugated by chemical bonding and anchored on the stent surface by a mussel-inspired adhesion mechanism. Subsequently, sirolimus was coated with poly lactic-glycolic acid on the heparinized stent surface. The heparin was well attached to the surface, and the surface was smooth after sirolimus coating. The smoothness of the surface was maintained after expansion of the stent. The amount of sirolimus released from the stent was 67.3% ± 4.55% within 7 days, followed by continual release up to day 28. The proliferation of smooth muscle cells was successfully arrested (51.3% ± 2.25% at 7 days of culture) by sirolimus released from the stent. Platelet adhesion was clearly prevented in the heparin-coated group (78.0 ± 8.00/1.8 cm2) compared to that in the heparin noncoated group (5.0 ± 1.00/1.8 cm2). Animal studies showed that the heparin and sirolimus-coated stent group had no obvious inflammatory response and no change in the fibrin score compared to those in the other groups. However, restenosis clearly decreased in the heparin and sirolimus-coated group (12.3% ± 3.54%) compared to the bare-metal stent group (27.5% ± 8.52%) and the heparin-coated group (25.3% ± 11.79%). These results suggest that heparinized surface-based sirolimus coating may be a useful approach for the prevention of restenosis and stent thrombosis.

Choice of Stent for Percutaneous Coronary Intervention of Saphenous Vein Grafts.

There are limited data on comparison of contemporary drug-eluting stent (DES) platforms, previous generation DES, and bare-metal stents (BMS) for percutaneous coronary intervention in saphenous vein grafts (SVG). We aimed to assess clinical outcomes following percutaneous coronary intervention to SVG in patients receiving bare-metal stents (BMS), first-generation DES, and newer generation DES in a large unselected national data set from the BCIS (British Cardiovascular Intervention Society). Patients undergoing percutaneous coronary intervention to SVG in the United Kingdom from January 2006 to December 2013 were divided into 3 groups according to stent use: BMS, first-generation DES, and newer generation DES group. Study outcomes included in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality. Patients (n=15 003) underwent percutaneous coronary intervention to SVG in England and Wales during the study period. Of these, 38% received BMS, 15% received first-generation DES, and 47% received second-generation DES. The rates of in-hospital major adverse cardiovascular events were significantly lower in patients treated with second-generation DES (odds ratio, 0.51; 95% confidence interval, 0.38-0.68; P<0.001), but not with first-generation DES, compared with BMS-treated patients. Similarly, 30-day mortality (odds ratio, 0.43; 95% confidence interval, 0.32-0.59; P<0.001) and 1-year mortality (odds ratio, 0.60; 95% confidence interval, 0.51-0.71; P<0.001) were lower in patients treated with second-generation DES, but not with first-generation DES, compared with the patients treated with BMS. Patients receiving second-generation DES for the treatment SVG disease have lower rates of in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality, compared with those receiving BMS.

A randomised trial of paclitaxel-eluting balloon after bare metal stent implantation vs. bare metal stent in ST-elevation myocardial infarction (the PEBSI study)

Our aim was to assess the safety and efficacy of paclitaxel-eluting balloon (PTX-B) treatment after bare metal stent (BMS) implantation in patients undergoing primary angioplasty. After BMS implantation, patients were randomised (1:1) to treatment with a PTX-B or no PTX-B treatment (BMS group). The primary endpoint was in-stent late luminal loss (LLL) at nine-month follow-up. OCT was carried out on the first 20% of consecutive patients included in the study. Two hundred and twenty-three patients were randomised (BMS: 112, PTX-B: 111). At nine months, median LLL was 0.80 mm (interquartile range [IQR] 0.36-1.26) in the BMS group vs. 0.31 mm (IQR 0.00-0.58) in the PTX-B group, p<0.0001. Binary restenosis was significantly lower in the PTX-B group: 29.8% vs. 2.2%, p<0.0001, 95% confidence interval (CI): 3.2-54.2. Nine-month OCT showed good strut coverage in both groups but greater in the BMS group (100±0.0% vs. 99.52±1.11%, p=0.03) with very low rates of malapposed struts per lesion. One-year MACE was significantly lower in the PTX-B group (12.5% vs. 3.6%, p=0.016). PTX-B after successful BMS implantation resulted in less LLL and better clinical outcomes as compared with a BMS-only strategy. This was associated with good stent strut coverage and very low rates of malapposed struts.

Drug-Eluting vs. Bare-Metal Stents: Is it a Matter of Vessel Size?

Background: Although drug-eluting stents (DES) for percutaneous coronary intervention have dramatically reduced the incidence of in-stent restenosis, their deployment for large-size coronary lesions is still controversial because of problems such as prolonged dual antiplatelet therapy, late in-stent thrombosis and costs. Aim: This study sought to evaluate the safety and effectiveness of drug-eluting stents (DES) compared to baremetal stents (BMS) for patients with large coronary vessels ≥ 3.5 mm. Methods: This is a retrospective case-control comparative study conducted in the cardiology A department of the university hospital Fattouma Bourguiba in Monastir. A total of 77 consecutive patients (80 lesions) who underwent, between October 2003 and March 2014, successfully DES implantation were compared to 73 consecutive patients (84 lesions) who were treated with BMS in large coronary vessels ≥ 3.5 mm. Results: The average age in our population was 59.7 ± 11.3 years with a male majority without any significant difference between the two groups. The DES group contained significantly more patients with diabetes (67.5% vs. 38.1%; p<0.0001) and a history of coronary heart disease (40% vs. 16.7%; p=0.001). The BMS group had significantly more procedures in the aftermath of MI (18.8% vs. 40.5%; p=0.002) including more primary angioplasty (6.7% against 47.1%; p=0.006). About two-thirds of the study patients had multi-vessel disease with equal distribution in both groups. The average duration of dual antiplatelet therapy was significantly prolonged in the DES group: 13.01 ± 8.31 months vs. 7.59 ± 8.19 months; p<0.0001. A mean follow of 27.87 ± 14.82 months was obtained. At 12 months, DES led to a significant reduction in the combined rate of major cardiac events by about 70% (OR=0.32; 95% CI: 0.119 to 0.858; p=0.019) without allowing a significant reduction in the rates of in-stent restenosis, in-stent thrombosis, target vessel revascularization or non-combined major cardiac events. During longterm follow-up, the benefit of DES in terms of MACE was maintained by allowing a 60% reduction in the combined rate of major cardiac events (OR=0.406; 95% CI: 0.172 to 0.955; p=0.035). Multivariate analysis identified the BMS as an independent predictor of major cardiac events and death. However, the type of stent does not appear as a factor influencing the ISR and target lesion revascularization rates. Conclusion: The results of our study demonstrate a clear clinical benefit of drug-eluting stents during angioplasty of large coronary arteries in reducing major cardiac events and death without having any effect on in-stent restenosis, in-stent thrombosis nor target lesion revascularization.

Comparison of Clinical Outcomes in Patients Undergoing Coronary Intervention with Drug-Eluting Stents or Bare-Metal Stents: A Nationwide Population Study.

The aim of this propensity score-matched cohort study was to investigate the prognostic impacts of drug-eluting stents (DES) and bare-metal stents (BMS) in patients undergoing percutaneous coronary intervention (PCI). We conducted a retrospective cohort study based on the National Health Insurance program. Patients who had undergone coronary stenting between Jan. 2007 and Dec. 2008 were recruited and monitored until the end of 2010. Subjects with either BMS or DES were matched 2:1 by propensity score, which adjusted for age, sex, stent number and Charlson comorbidity index (CCI). The Kaplan-Meier method and Cox regression models were used for prognostic analyses. Among a total of 966 patients with a mean age of 66 years, 644 subjects had BMS and 322 subjects had DES. The incidence of myocardial infarction (MI) and death were significantly lower in the DES group as compared with the BMS group for the three-year follow-up duration. With adjustments for age, sex, premium-based monthly salary, levels of hospital care, stent number, CCI, medications, and acute coronary syndrome presentation in the index hospitalization, use of DES rather than BMS was associated with reduced adverse coronary events (hazard ratio and 95% confidence interval: 0.55, 0.38-0.81 in the whole population, and 0.44, 0.26-0.73 in the subgroup patients with stable coronary artery disease). Implantation of DES was related to better outcomes than for BMS, in terms of reducing MI and mortality after PCI. The survival benefit for patients with DES was even greater in patients with stable coronary artery disease.

The Control of Drug Release and Vascular Endothelialization after Hyaluronic Acid-Coated Paclitaxel Multi-Layer Coating Stent Implantation in Porcine Coronary Restenosis Model.

Background and ObjectivesHyaluronic acid (HA) is highly biocompatible with cells and the extracellular matrix. In contrast to degradation products of a synthetic polymer, degradation products of HA do not acidify the local environment. The aim of this study was to fabricate an HA-coated paclitaxel (PTX)-eluting stent via simple ionic interactions and to evaluate its effects in vitro and in vivo.Materials and MethodsHA and catechol were conjugated by means of an activation agent, and then the stent was immersed in this solution (resulting in a HA-coated stent). After that, PTX was immobilized on the HA-coated stent (resulting in a hyaluronic acid-coated paclitaxel-eluting stent [H-PTX stent]). Study groups were divided into 4 groups: bare metal stent (BMS), HA, H-PTX, and poly (L-lactide)-coated paclitaxel-eluting stent (P-PTX). Stents were randomly implanted in a porcine coronary artery. After 4 weeks, vessels surrounding the stents were isolated and subjected to various analyses.ResultsSmoothness of the surface was maintained after expansion of the stent. In contrast to a previous study on a PTX-eluting stent, in this study, the PTX was effectively released up to 14 days (a half amount of PTX in 4 days). The proliferation of smooth muscle cells was successfully inhibited (by 80.5±12.11% at 7 days of culture as compared to the control) by PTX released from the stent. Animal experiments showed that the H-PTX stent does not induce an obvious inflammatory response. Nevertheless, restenosis was clearly decreased in the H-PTX stent group (9.8±3.25%) compared to the bare-metal stent group (29.7±8.11%).ConclusionA stent was stably coated with PTX via simple ionic interactions with HA. Restenosis was decreased in the H-PTX group. These results suggest that HA, a natural polymer, is suitable for fabrication of drug-eluting stents (without inflammation) as an alternative to a synthetic polymer.

Effect of the type of stent on results of coronary artery bypass grafting in multivessel disease patients

BackgroundPercutaneous coronary interventions (PCI) before coronary artery bypass grafting (CABG) increased recently. Consequently, patients are referred for CABG with severe pathology affecting their results. Several studies compared CABG with PCI and effect of previous PCI on after coming CABG, while studies addressing the effect of the type of stent on the after coming CABG are lacking. MethodsData of 200 CABG patients with previous PCI done at the National Heart Institute (NHI) and other centers between 2011 and 2015, are observed prospectively with mean follow-up of 12 months. The patients were divided into two groups: Group I (n = 100, mean age 52.20 years, 9 women) underwent CABG Bare metal stent (BMS) PCI and group II (n = 100, mean age 50.25, 18 women) had prior Drug eluting stent (DES) PCI before CABG. ResultsGroup I: the mean number of stents was 1.95 versus 2.98 in group II (P < 0.05). Patients with DES PCI presented for CABG with higher incidence of previous MI (P = 0.004) and unplanned CABG (P = 0.0000001). The total number of grafts was significantly higher in the BMS PCI group 3.12 ± 0.73 versus 2.46 ± 0.85 in Group II (P value = 0.00001). Postoperative inotropes, morbidity and hospital stay were higher in the DES PCI group (P value = 0.02, 0.01 and 0.000595 receptively). Post-operative echo showed better EF, RSWMA and dimensions in group I. Morbidities and mortality were higher in patients with prior DES PCI. Postoperative echo emphasized better benefit from CABG in patients of group I (post BMS PCI). ConclusionDES PCI showed negative impact on the outcome of after coming CABG.

Impact of stent type and prolonged dual antiplatelet therapy on long-term clinical outcomes in hemodialysis patients with coronary artery disease.

The aim of this study was to address 7-year clinical outcomes and impact of prolonged dual antiplatelet therapy (DAPT) after coronary stenting in hemodialysis patients. Our study included 123 consecutive hemodialysis patients who had undergone percutaneous coronary intervention with a drug-eluting stent (DES) or bare-metal stent (BMS) (DES: 64, BMS: 59) in our institution. We compared long-term clinical outcomes following DES with BMS implantation as well as clinical outcomes in patients on DAPT for ≥1year (DAPT on group, 89) with those on DAPT for <1year (DAPT off group, 34). We evaluated bleeding events and major adverse cardiac events (MACE), including cardiac death, non-fatal myocardial infarction, target vessel revascularization, and stent thrombosis. At 1year after stenting, the incidence of MACE was significantly lower in the DES group than in the BMS group (DES versus BMS: 33.2 versus 51.8%; p=0.045). However, this advantage of DES disappeared by the 7th year (DES versus BMS: 66.0 versus 70.0%; p=0.42). The cumulative incidence of MACE beyond 1year was significantly higher in the DAPT on group than in the DAPT off group (DAPT on versus DAPT off: 51.3 versus 18.5%; p=0.047). The bleeding events in the DAPT on group were 5.1 times greater than in the DAPT off group (DAPT on versus DAPT off: 16.4 versus 3.2%; p=0.06). Use of DES and prolonged DAPT did not improve 7-year clinical outcomes in hemodialysis patients with coronary artery disease.

Paclitaxel Drug-eluting Tracheal Stent Could Reduce Granulation Tissue Formation in a Canine Model.

Background:Currently available silicone and metallic stents for tracheal stenosis are associated with many problems. Granulation proliferation is one of the main complications. The present study aimed to evaluate the efficacy of paclitaxel drug-eluting tracheal stent in reducing granulation tissue formation in a canine model, as well as the pharmacokinetic features and safety profiles of the coated drug.Methods:Eight beagles were randomly divided into a control group (bare-metal stent group, n = 4) and an experimental group (paclitaxel-eluting stent group, n = 4). The observation period was 5 months. One beagle in both groups was sacrificed at the end of the 1st and 3rd months, respectively. The last two beagles in both groups were sacrificed at the end of 5th month. The proliferation of granulation tissue and changes in tracheal mucosa were compared between the two groups. Blood routine and liver and kidney function were monitored to evaluate the safety of the paclitaxel-eluting stent. The elution method and high-performance liquid chromatography were used to characterize the rate of in vivo release of paclitaxel from the stent.Results:Compared with the control group, the proliferation of granulation tissue in the experimental group was significantly reduced. The drug release of paclitaxel-eluting stent was the fastest in the 1st month after implantation (up to 70.9%). Then, the release slowed down gradually. By the 5th month, the release reached up to 98.5%. During the observation period, a high concentration of the drug in the trachea (in the stented and adjacent unstented areas) and lung tissue was not noted, and the blood test showed no side effect.Conclusions:The paclitaxel-eluting stent could safely reduce the granulation tissue formation after stent implantation in vivo, suggesting that the paclitaxel-eluting tracheal stent might be considered for potential use in humans in the future.

Randomised comparison of drug-eluting versus bare-metal stenting in patients with non-ST elevation myocardial infarction

ObjectiveThe superiority of drug-eluting stents (DES) over bare-metal stents (BMS) in patients with ST elevation myocardial infarction (STEMI) is well studied; however, randomised data in patients with non-ST elevation myocardial...

Clinical, humanistic, and economic outcomes between drug-eluting stent (DES) and bare metal stent (BMS): 18-month follow-up study

Background: Percutaneous coronary intervention (PCI) is one of the most performed interventions for ischemic heart diseases. In Hong Kong, the total number of patient discharges and deaths for ischemic heart diseases in 2009 was 33,363, including 4,360 deaths. There are over 5,000 cases of PCI yearly. This study aimed to compare clinical, economic, and humanistic outcomes among patients receiving drug-eluting stent (DES) or bare metal stent (BMS) in Hong Kong.Methods: Patients who received stent implantation between September 15, 2009 and October 11, 2010 in Prince of Wales Hospital, Hong Kong, were recruited and followed for 18 months. Occurrence of major adverse cardiac events (cardiac death, non-fatal MI, TLR and TVR) was employed as the clinical outcome measurements. Improvement in quality-of-life by stent interventions was measured as quality-adjusted life-year (QALY). EQ-5D questionnaire was adopted to assess the QALY gained. Cost-utility analysis and cost-effectiveness analysis for BMS and DES were employed as the economic outcome measurement.Results: Six hundred and eighty-four patients (DES = 402; BMS = 282) were included. From 0–18 months, TLR rate (2.7% vs 3.5%, p = .549) and TVR rate (3.7% vs 6.4%, p = .111) were lower in the DES group, but without statistical significance. EQ VAS (71.06 ± 14.56 vs 71.07 ± 16.57, p = .998) and utility score (0.81 ± 0.17 vs 0.78 ± 0.16, p = .162) were comparable between DES and BMS group. Overall, the cost per QALY gained was HKD + 1,178,100 and ICER was HKD + 187,000 (1USD = 7.8 HKD).Conclusions: No significant difference in TVR, TLR rates, EQ VAS, and utility score was found between the DES and BMS group. The higher cost of index procedure for the DES group was found to be partly offset by reduced cost of follow-up, offering cost-effectiveness in ACS patients, predominantly in STEMI patients. DES was recommended for STEMI patients.

Frequency of Vascular Inflammation and Impact on Neointimal Proliferation of Drug Eluting Stents in Porcine Coronary Arteries.

We aimed to describe the frequency of vascular inflammatory reactions with second generation drug eluting stents (DES) compared to first generation DES, and analyze the impact on inflammation and neointimal proliferation in a porcine coronary model. A total of 26 stents (7 multi-link VISION, 6 CYPHER, 6 TAXUS and 7 XIENCE V) were deployed in the coronary arteries of 10 domestic swine for 28 days, after which each stent was harvested and processed (divided into 8 or 9 segments) for histomorphometric analysis. A total of 202 histological segments [146 DES and 56 bare metal stents (BMS)] were included in this study. The mean neointimal thickness was significantly reduced in the DES group compared to the BMS group. The DES group had higher injury scores (DES = 0.99 ± 0.79 versus BMS = 0.67 ± 0.44, p < 0.004), inflammatory scores (DES = 2.09 ± 1.54 versus BMS = 0.64 ± 0.98, p < 0.001) and presence of para-strut granulomas (DES = 35% versus BMS = 2%, p < 0.001). In logistic regression analysis, the presence of para-strut granulomas correlated with an area of stenosis > 50% (RR: 6.11, 95% CI: 2.97 to 12.59, p = 0.001). In the DES group, the second generation stents had a lower neointimal area (XIENCE V: 1.64 ± 0.90 mm2) compared to the first generation stents (TAXUS: 2.36 ± 1.56 mm2, p = 0.005; CYPHER 2.78 ± 1.82 mm2, p = 0.001). The XIENCE V stents had lower inflammatory scores and lower frequency of para-strut granulomas compared to the first generation stents. Second generation DES had a lower incidence of vascular inflammatory reactions compared to first generation DES. This biological phenomenon appears to influence the patterns of neointimal formation.

Is a bare-metal stent still useful for improving the outcome of percutaneous coronary intervention? From the FU-Registry

BackgroundPercutaneous coronary intervention (PCI) with a drug-eluting stent (DES) is increasingly being used for the treatment of coronary artery diseases. However, the role and effectiveness of PCI with a bare metal stent (BMS) have not yet been established. MethodsAmong the 2197 patients (2653 lesions) treated with PCI from 2003 to 2012 at three institutions in Fukuoka, 859 patients (1032 lesions) without acute coronary syndrome and in whom we were able to perform follow-up coronary angiography after stent placement and collect detailed data were selected for this study. Among the patients treated by BMS, the cut-off lesion reference for the development of in-stent restenosis (ISR) was calculated by comparing patients with and without ISR. In all patients with a lesion reference above/below the cut-off point of BMS-ISR, medium-term clinical and angiographic outcomes were compared between the BMS and DES groups. ResultsIn patients treated with a BMS, the lesion reference [odds ratio 0.68, 95% confidence interval (CI) 0.43–0.97, p=0.03] was strongly correlated with ISR, and the area under the receiver operating characteristic curve was 0.704, with moderate accuracy. Calculation of the cut-off lesion reference for BMS-ISR, using a relative cumulative frequency distribution and a sensitivity/specificity curve, showed that the cut-off lesion reference for BMS-ISR was 3.08mm, and the sensitivity/specificity was 60.4%. For the DES and BMS groups in cases with a lesion reference over 3.08mm, BMS placement did not correlate with ISR (odds ratio 0.98, 95% CI 0.85–1.12), and there was also no correlation between BMS and major adverse cardiac events. ConclusionIn patients with a lesion reference≧3.08mm, medium-term clinical and angiographic outcomes were equivalent between the use of a DES and BMS. Thus, BMS placement is well worth considering, especially in patients with a lesion reference≧3.08mm, in whom double-antiplatelet therapy needs to be stopped at an early stage.

Abstract 652: Coronary Angioscopic Observation of Extremely Late Arterial Repair Catch-up after Sirolimus-eluting Stent Implantation

Sirolimus, a bio-suppressive drug, delays coronary arterial repair after implantation of Cypher sirolimus-eluting stents (SES), a representative first generation drug-eluting stent. It remains unclear, however, whether this delayed repair would catch up with bare metal stents (BMS) along extremely long observation. The aim of this study was angioscopic comparison of coronary arterial repair through a decade after implantation of SES and BMS. Enrolled were 31 patients with previous implantation of SES (n = 22) or BMS (n = 9). Duration after stent implantation (DSI) ranged from 3 to 10.5 years in both groups. Thirty-seven SES were implanted into the SES group and 17 BMS into the BMS group. The 54 stented segments were analyzed by quantitative coronary angiography (QCA) and non-obstructive coronary angioscopy (CAS). Under continuous flush of low-molecular-weight dextran, CAS visualized in-stent appearance, i.e. endothelial stent coverage (ESC), presence of yellow plaque (YP), and in-stent mural thrombi (ISMT). ESC was semi-quantified into 4 grades (grade 0, no coverage; grade 1, thin coverage; grade 2, decent coverage; grade 3, full coverage). QCA showed in-stent restenosis neither in SES- nor BMS-implanted segments (% diameter stenosis 14.8 ± 7.9 vs. 16.2 ± 8.2, respectively). Incidence of YP was 27% in SES and 6% in BMS (P &lt; 0.03). Incidence of ISMT was 24% in SES, whereas never in BMS. ESC grade of BMS was either grade 1 (24%) or grade 3 (76%). SES-implanted segments were divided into two groups, i.e. DSI &gt; 8 years (n = 5) and DSI &lt; 8 years (n = 32). In the former (10.5 &gt; DSI &gt; 8 years), ESC grade of SES was either grade 1 (40%) or grade 3 (60%), being similar to ESC after BMS implantation. In the latter (8 &gt; DSI &gt; 3 years), however, ESC grade varied from grade 0 (6%), grade 1 (63%), grade 2 (25%), and grade 3 (6%). Incidence of YP or ISMT was 60% in the former, suggesting progression of neoatherosclerosis at extremely late phase. In conclusion, from the viewpoint of ESC, coronary arterial repair at SES implantation appeared to catch up with BMS at around 8 years later, although incidence of YP or ISMT remained still greater in SES than BMS at extremely late phase.