Bare Metal Stents Group Research Articles

Vessel healings after stenting with different polymers in STEMI patients.

BackgroundDifferent stents implantation in ST-segment elevation myocardial infarction (STEMI) patients may influence the long term prognosis by affecting vessel healings after stenting. The aim of this study was to evaluate the vessel healings after implantation of drug eluting stents (DES) with biodegradable or durable polymer or of bare-metal stents (BMS) in patients with acute STEMI.MethodsThis study included 50 patients, who underwent follow up angiogram and optical coherence tomography (OCT) assessment about one year after percutaneous coronary intervention (PCI) for STEMI. According to the initial stents types, these patients were classified to durable (n = 19) or biodegradable polymer sirolimus-eluting stents (n = 15), or BMS (n = 16) groups. The conditions of stent struts coverage and malapposition were analyzed with OCT technique.ResultsA total of 9003 struts were analyzed: 3299, 3202 and 2502 from durable or biodegradable polymer DES, or BMS, respectively. Strut coverage rate (89.0%, 94.9% and 99.3%, respectively), malapposition presence (1.7%, 0.03% and 0 of struts, respectively) and average intimal thickness over struts (76 ± 12 µm, 161 ± 30 µm and 292 ± 29 µm, respectively) were significantly different among different stent groups (all P < 0.001).ConclusionsVessel healing status in STEMI patients is superior after implantation of biodegradable polymer DES than durable polymer DES, while both are inferior to BMS.

Durability of the balloon-expandable covered versus bare-metal stents in the Covered versus Balloon Expandable Stent Trial (COBEST) for the treatment of aortoiliac occlusive disease

The Covered vs Balloon Expandable Stent Trial (COBEST) is the first multicenter trial to investigate the patency of covered stents (CSs) and bare-metal stents (BMSs) in the treatment of aortoiliac arterial disease. The short-term results demonstrated that CSs were superior to BMSs in maintaining patency for TransAtlantic Inter-Society Consensus (TASC) C and D lesions at 18months and were equivalent to BMSs for TASC B lesions. The current study was conducted to determine if the initial patency advantage of CSs over BMSs was sustained at the 5-year follow-up. A retrospective post hoc analysis of COBEST was performed. Originally, 125 patients with 168 iliac arteries were prospectively enrolled and randomly assigned to receive a CS or BMS. In this study, 77 of the 125 patients (61.6%; 119 limbs) were assessed at 60months for the primary and secondary end points, with particular attention paid to the outcomes stratified according to TASC lesion severity. The primary end point was the rate of binary stenosis or freedom from stent occlusion of the treated area, as determined by ultrasound imaging or quantitative visual angiography. The 5-year results of the COBEST showed that the CS had a significantly higher patency rate than the BMS at 18, 24, 48, and 60months (95.1%, 82.1%, 79.9%, 74.7% for CS vs 73.9%, 70.9%, 63% and 62.5% for BMS; log-rank test, P=.01). On multivariate analysis, the type of stent used (hazard ratio [HR], 2.797; 95% confidence interval [CI], 1.471-5.318; P= .002) and the Rutherford classification (HR, 2.019; 95% CI, 1.278-3.191; P= .026) significantly affected the adjusted primary patency. On subgroup analysis, the CS showed significantly higher patency and a survival benefit compared with the BMS in TASC C and D lesions (HR, 8.639; 95% CI, 54.253-75.753; P= .003). Moreover, fewer patients received target limb revascularization in the CS group than in the BMS group (odds ratio, 2.32; 95% CI, 1.47-3.36; P= .02); however, there was no statistically significant difference in the rate of amputations between the groups. The 5-year results of the COBEST demonstrated that the CS has an enduring patency advantage over the BMS in both the short and long terms. Furthermore, the CS showed acceptable patency rates for the treatment of more severe TASC C and D lesions, and patients who received a CS required fewer revascularization procedures. However, the choice of stent did not affect the rate of major limb amputations.

Clinical outcomes of drug-eluting stents versus bare-metal stents in patients with cardiogenic shock complicating acute myocardial infarction

BackgroundTo investigate the cardiovascular (CV) outcomes of drug-eluting stents (DESs) versus bare-metal stents (BMSs) in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). MethodsData from the Taiwan National Health Insurance Research Database was analyzed between January 1, 2007 and December 31, 2011. A total of 3051 AMI patients in CS were selected as the study cohort. Their clinical outcomes were evaluated by comparing 1017 subjects who used DESs to 2034 matched subjects who used BMSs. ResultsThe risk of the primary composite outcome (i.e., death, myocardial infarction, stroke, and coronary revascularization) was significantly lower in the DES group compared with the BMS group [56.1% vs. 66.2%, hazard ratio (HR), 0.74; 95% CI, 0.67–0.81] with a mean follow-up of 1.35years. The patients who received DESs had a lower risk of coronary revascularization (HR, 0.78; 95% CI, 0.67–0.91) and death (HR, 0.70; 95% CI, 0.62–0.79) than those who used BMSs. However, the risks of myocardial infarction (HR, 0.89; 95% CI, 0.66–1.18), ischemic stroke (HR, 1.02; 95% CI, 0.67–1.53) and major bleeding (HR, 0.80; 95% CI, 0.56–1.14) were similar between the two groups. ConclusionsAmong patients with CS complicating AMI, DES implantation significantly reduced the risk of percutaneous coronary revascularization and death compared to BMS implantation.

One-year cardiovascular outcomes of drug-eluting stent versus bare-metal stent implanted in diabetic patients with acute coronary syndrome

BackgroundThe outcomes of drug-eluting stent (DES) versus bare-metal stent (BMS) use in patients with diabetic mellitus (DM) and acute coronary syndrome (ACS) are rarely reported in Taiwan. This study aimed to investigate the 1-year cardiovascular outcomes of DESs versus BMSs implanted in Taiwanese patients with DM and ACS. MethodsFor this study, we collected and analyzed patient information from the database of the Taiwan ACS Full Spectrum registry regarding characteristics and cardiovascular events in participants with DM and ACS who received implantation of either BMS (BMS group) or DES (DES group) from October 2008 to January 2010. ResultsWe found that several characteristics significantly varied between the groups. Compared with the BMS group (n = 575), the DES group (n = 199) had significantly lower rates of in-hospital cardiogenic shock (1.5% vs. 4.9%, p = 0.037) and acute renal failure (0.5% vs. 4.5%, p = 0.008), all-cause mortality (5.0% vs. 8.9%, p = 0.048), and major adverse cardiac events (MACEs) at 1 year (11.1% vs. 18.6%, p = 0.006) with an identical target vessel revascularization (TVR) rate (6.0% vs. 7.3%, p = 0.395). The BMS group had significantly higher risk-adjusted all-cause mortality [hazard ratio (HR) = 2.4, 95% confidence interval (CI) 1.0–5.7; p = 0.048] and MACE (HR = 2.2, 95% CI 1.2–3.9; p = 0.011) at 1 year with identical risks of TVR (HR = 1.3, 95% CI 0.6–2.9; p = 0.505) and nonfatal myocardial infarction (HR = 1.5, 95% CI 0.5–4.4; p = 0.478). ConclusionThe results of this study support the use of DES over BMS in Taiwanese patients with DM and ACS, providing the clinical benefits of lower rates of total mortality and MACE, and without increased TVR at 1 year in a real-world setting.

Paclitaxel-coated balloon plus bare-metal stent for de-novo coronary artery disease: final 5-year results of a randomized prospective multicenter trial.

The PERfECT Stent Study compared paclitaxel-coated balloon (PCB) angioplasty plus bare-metal stent (BMS) implantation with BMS alone in de-novo lesions in native coronary artery disease. Angiographic follow-up after 6 months showed the superiority of the additional PCB. We evaluated a potential late catch-up phenomenon with the use of PCB. In the prospective, multicenter, single-blind, randomized PERfECT Stent trial, 120 patients were assigned to either PCB angioplasty plus BMS implantation or BMS alone. For BMS, the endothelial progenitor cell capturing stent was used. Dual antiplatelet therapy was recommended for 3 months. The clinical endpoint for 5-year follow-up was a composite of cardiac death, myocardial infarction attributed to the target vessel, or target lesion revascularization. The follow-up rate after 5 years was 97%. Baseline and procedural characteristics did not differ. At the 5-year follow-up, clinically driven target lesion revascularization was 23.2% in the BMS group versus 15% with PCB plus BMS (P=0.26). The clinical endpoint (major adverse cardiac event) was 30.4% with BMS and with 23.5% lower with PCB plus BMS. No definite or probable stent thrombosis was found in either group with a dual antiplatelet therapy for 3 months for the total period. PCB angioplasty plus BMS was superior to BMS alone for the treatment of de-novo lesions. The combined clinical endpoint was lower with PCB plus BMS at 6 months and remained lower after 5 years. There was no late catch-up phenomenon (http://www.clinicaltrials.gov; NCT 00732953).

Very late stent thrombosis with second generation drug eluting stents compared to bare metal stents: Network meta-analysis of randomized primary percutaneous coronary intervention trials.

The relative safety of drug-eluting stents (DES) and bare-metal stents (BMS) in primary percutaneous coronary intervention (PPCI) in ST elevation myocardial infarction (STEMI) continues to be debated. The long-term clinical outcomes between second generation DES and BMS for primary percutaneous coronary intervention (PCI) using network meta-analysis were compared. Randomized controlled trials comparing stent types (first generation DES, second generation DES, or BMS) were considered for inclusion. A search strategy used Medline, Embase, Cochrane databases, and proceedings of international meetings. Information about study design, inclusion criteria, and sample characteristics were extracted. Network meta-analysis was used to pool direct (comparison of second generation DES to BMS) and indirect evidence (first generation DES with BMS and second generation DES) from the randomized trials. Twelve trials comparing all stents types including 9,673 patients randomly assigned to treatment groups were analyzed. Second generation DES was associated with significantly lower incidence of definite or probable ST (OR 0.59, 95% CI 0.39-0.89), MI (OR 0.59, 95% CI 0.39-0.89), and TVR at 3 years (OR 0.50: 95% CI 0.31-0.81) compared with BMS. In addition, there was a significantly lower incidence of MACE with second generation DES versus BMS (OR 0.54, 95% CI 0.34-0.74) at 3 years. These were driven by a higher rate of TVR, MI and stent thrombosis in the BMS group at 3 years. There was a non-significant reduction in the overall and cardiac mortality [OR 0.83, 95% CI (0.60-1.14), OR 0.88, 95% CI (0.6-1.28)] with the use of second generation DES versus BMS at 3 years. Network meta-analysis of randomized trials of primary PCI demonstrated lower incidence of MACE, MI, TVR, and stent thrombosis with second generation DES compared with BMS. © 2016 Wiley Periodicals, Inc.

Drug-eluting stents appear superior to bare metal stents for vein-graft PCI in vessels up to a stent diameter of 4 mm.

Research trials have shown improved short-term outcome with drug-eluting stents (DES) over bare metal stents (BMS) in saphenous vein graft (SVG) percutaneous coronary intervention (PCI), primarily by reducing target vessel revascularization (TVR) for in-stent restenosis. We compared the outcomes in patients undergoing SVG stent implantation treated with DES or BMS. In exploratory analyses we investigated the influence of stent generation and diameter. Data were obtained from a prospective database of 657 patients who underwent PCI for SVG lesions between 2003 and 2011. A total of 344 patients had PCI with BMS and 313 with DES. Propensity scores were developed based on 15 observed baseline covariates in a logistic regression model with stent type as the dependent variable. The nearest-neighbour-matching algorithm with Greedy 5-1 Digit Matching was used to produce two patient cohorts of 313 patients each. We assessed major adverse cardiac events (MACE) out to a median of 3.3 years (interquartile range: 2.1-4.1). MACE was defined as all-cause mortality, myocardial infarction (MI), TVR and stroke. There was a significant difference in MACE between the two groups in favour of DES (17.9% DES vs. 31.2% BMS group; p = 0.0017) over the 5-year follow-up period. MACE was driven by increased TVR in the BMS group. There was no difference in death, MI or stroke. Adjusted Cox analysis confirmed a decreased risk of MACE for DES compared with BMS 0.75 (95% confidence interval (CI) 0.52-0.94), with no difference in the hazard of all-cause mortality (hazard ratio: 1.08; 95% CI: 0.77-1.68). However, when looking at stent diameters greater than 4 mm, no difference was seen in MACE rates between BMS and DES. Overall in our cohort of patients who had PCI for SVG disease, DES use resulted in lower MACE rates compared with BMS over a 5-year follow-up period; however, for stent diameters over 4 mm no difference in MACE rates was seen.

Author Reply to Letter to the Editor: Drug-Eluting Stents versus Bare-Metal Stents in Taiwanese Patients with Acute Coronary Syndrome: An Outcome Report of a Multicenter Registry.

The article entitled “Drug-Eluting Stents versus Bare-Metal Stents in Taiwanese Patients with Acute Coronary Syndrome: An Outcome Report of a Multicenter Registry” was published in the Journal of Acta Cardiologica Sinica in November 2014.1 Several experts offered constructive comments about this article in the ACS letter to the Editor section, and their comments focused on two primary points. First, that the 1-year survival benefit of drug-eluting stents (DES) group should be adjusted by the patients’ baseline renal function and in-hospital acute kidney injury (AKI). Second, the results regarding mortality differences shown in the article1 and another systemic review2 were inconsistent between patients treated with implanted DES and bare-metal stents (BMS). Although we could hardly list all variables potentially affecting the outcome in the article, I concur with the experts’ comment indicating that baseline renal function and in-hospital AKI should be adjusted when investigating clinical outcomes between acute coronary syndrome (ACS) patients treated with implantation of DES and BMS. I am unaware of the changes in cardiovascular risks at 1 year after adjustment by baseline renal function and in-hospital AKI because the analytic center organized for the registry has been terminated. I suppose that the 1-year cardiovascular outcomes determined using Kaplan-Meier analysis should remain unchanged between the DES and BMS groups, even taking into account the estimated glomerular filtration rate (eGFR) at baseline. I would also speculate that the adjusted risks by several variables including baseline eGFR for a variety of cardiovascular composites (p < 0.01 for all) would remain statistically powerful between the groups. However, the marginal differences for all-cause mortality (p = 0.026) and target vessel revascularization (p = 0.035) are likely to be challenged (Table 3). On the other hand, it is well-documented that chronic kidney disease (CKD) is a powerful independent predictor for clinical outcomes in patients receiving stentings.3-7 Nonetheless, the values of baseline eGFR may be influenced by and/or accompanied by several clinical circumstances during the event of ACS.3-7 According to the 2012 Kidney Disease Improving Global Outcomes (KDIGO) clinical practice guideline, CKD is defined as kidney damage or eGFR < 60 ml/min/1.73 m2 for a period exceeding three months.8 Therefore, the researchers did not accurately determine “true” CKD or the stages of CKD merely based upon one value of serum creatinine recorded in each case report form without assessing renal function for 3 months or more. Thus, the incidence of CKD (33.6%) could possibly have been overestimated.5,6 A proportional number of cases with CKD previously identified by one value of eGFR < 60 ml/min/1.73 m2 may be those cases with “secondary and/or transient” renal dysfunction. In addition, renal function of eGFR 60 ml/min/1.73 m2 at baseline was reported to be associated with higher rates of negative factors such as elderly, hypertension, diabetes mellitus, dyslipidemia, history of cardiovascular diseases, shock on presentation, multi-vessel coronary disease, and so on.3-7 These negative factors, including renal dysfunction, may account for the worse clinical outcome.3-7 Moreover, the impact of implanted DES versus BMS on mortality in ACS patients remains controversial.9-12 Additionally, physicians should not only be concerned with patient mortality, but other clinical endpoints as well. As described in the “Discussion” section of the article (page 560-561), the differences in mortality as analyzed from the registry studies and randomized controlled trials (RCTs) are inconsistent.9-12 It is reasonable that the systemic review the experts referenced that enrolled more than 14,500 patients with coronary artery disease (not all ACS patients) in 47 RCTs showed no statistically significant difference in mortality between DES and BMS groups.2 In contrast, the present result regarding survival outcome is compatible with other results from several registry studies.9-12 Taken together, the experts provided their constructive comments and highlighted the points which may remind researchers to consider the effect of baseline renal function, CKD and/or in-hospital AKI on cardiovascular outcome in subsequent study designs. In conclusion, we suggest that there is merit to the idea that the effect of renal function on cardiovascular outcome should be considered, and to assess renal function exceeding 3 months in designing further similar studies.

0234: Drug-eluting stents versus bare-metal stent in large coronary arteries

Although drug-eluting stents (DES) have been shown to dramatically reduce restenosis and improve the rate of event-free survival, the benefit of DES appears to be limited to restenosis. In this retrospective, single-center study we aimed to compare the long-term outcomes of DES versus bare-metal stent (BMS) in large coronary arteries (diameter ≥3.5mm). A total of 164 consecutive patients (mean age 60 years) required percutaneous coronary intervention with stents ≥3.5mm in diameter, 84 were BMS and 80 DES. The primary endpoint was major adverse cardiac events (MACE) defined as angiographically defined in-stent restenosis (ISR), stent thrombosis and death from any cause. A mean clinical follow up of 28 months was obtained. The DES group had higher rates of diabetes (63% vs 37%, p=0.001), previous CAD (74% vs 25%, p=0.001) and previous PCI (69% vs 31%, p=<0.04). There was no significant difference between the two groups regarding the rate of hyper-tension, dyslipidemia, smokers and the mean left ventricular ejection fraction. There was a higher average stent length in the DES group (18.7 vs 16.3, p=0.011) as well as a lower average stent diameter (3.54 vs 3.63, p=0.003). There was a significant difference in MACE between the two groups in favour of DES (11.3% DES vs 23.8% BMS group, p=0.04) at 28 months. The rate of in-stent restenosis (ISR) was significantly reduced among patients receiving DES with ISR rates of 15.8% among patients receiving DES compared to 41.7% among those receiving BMS (p=0.025). There were no significant differences in the rate of death or stent thrombosis. In patients requiring stenting of large coronary arteries, there was reduced MACE in patients treated with DES. This benefit was primarily driven by decreased in-stent restenosis rate.

Development of a New Hybrid Biodegradable Drug-Eluting Stent for the Treatment of Peripheral Artery Disease.

This study aimed to develop a new biodegradable stent for peripheral artery disease (PAD) that could provide sufficient radial force to maintain long-term patency and flexibility. All self-expandable hybrid biodegradable stents were designed by using a knitting structure composed of poly-L-lactic acid (PLLA) and nitinol. Four different types of stents were implanted in 20 iliac arteries in 10 mini pigs as follows: a bare-metal stent (BMS) (group 1, n = 5), a drug-free hybrid stent (group 2, n = 5), a 50% (50 : 100, w/w) paclitaxel (PTX)/poly-lactide-co-glycolic acid (PLGA; fast PTX-releasing form) hybrid stent (group 3, n = 5), and a 30% (30 : 100, w/w) PTX/PLGA (slow PTX-releasing form) hybrid stent (group 4, n = 5). We performed follow-up angiography and intravascular ultrasonography (IVUS) at 4 and 8 weeks. In a comparison of groups 1, 2, 3, and 4, less diameter stenosis was observed in the angiographic analysis for group 4 at the 4-week follow-up (19.0% ± 12.7% versus 39.3% ± 18.1% versus 46.8% ± 38.0% versus 4.8% ± 4.2%, resp.; p = 0.032). IVUS findings further suggested that the neointima of the patients in group 4 tended to be lesser than those of the others. Our new biodegradable 30% PTX/PLGA (slow-releasing form) stent showed more favorable results for patency than the other stent types.

The efficacy of everolimus-eluting stent implantation in patients with ST-segment elevation myocardial infarction: outcomes of 2-year clinical follow-up.

First-generation drug-eluting stents (DES) demonstrated delay in vascular healing and increase in incidence of late and very late stent thrombosis compared with bare-metal stents (BMS). Second-generation DES, however, have shown a reduction of late and very late stent thrombosis compared with first-generation DES. Thus, we decided to evaluate whether the second-generation everolimus-eluting stent (EES) has an advantage over BMS in Japanese patients with ST-segment elevation myocardial infarction (STEMI). This study was conducted in two centers, retrospective, non-randomized and observational design in patients with STEMI. Three-hundred eighty patients were randomly selected to receive EES (198 patients) or cobalt-chromium BMS (182 patients). The primary endpoints were cardiac death, recurrent myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis (ST). At 2years, the rates of TLR, TVR, and recurrent MI were significantly lower in the EES group than in the BMS group (TLR 1.5 vs. 8.3%, p<0.05; TVR 2.5 vs. 9.4%, p<0.05; recurrent MI 1.0 vs. 4.1%, p<0.05), and the rate of ST was also significantly lower in the EES group than in the BMS group (0.5 vs. 4.3%, p<0.05). Thus, major adverse cardiac events defined at the composite cardiac death, MI, TLR, TVR, or ST were significantly lower in EES group than in BMS group (3.0 vs. 9.9%, p=0.008). The rate of cardiac death, however, did not differ between both groups. In STEMI patients, EES may be associated with improved outcomes-specifically, a significant reduction in TVR, ST, and recurrent MI compared to BMS throughout 2years.

Renal Transplant Arterial Stenosis Treated With Bare-Metal Versus Drug-Eluting Stents: Comparison of Treatment Outcomes

IntroductionThis study aims to evaluate outcomes of bare-metal stents (BMS) versus drug-eluting stents (DES) in patients who undergo stenting for transplant renal arterial stenosis. Materials and MethodsWe retrospectively reviewed records of renal transplantation patients who underwent transplant renal arterial stenting from September 2009 to September 2013. All stents greater than 5 mm were excluded to allow for equivalent comparison between the DES and BMS groups. Statistical comparisons were performed using a two-tailed Fischer exact test, and analysis of continuous variables was analyzed using a one-way analysis of variance. ResultsThe final study population included a total of 18 patients who received either BMS or DES (11 and 7 patients, respectively) for transplant renal arterial stenosis. The most common indications for stenting were increasing creatinine level and abnormal Doppler velocities. There were more re-interventions with BMS (n = 4/11) than DES (n = 0/7), but the trend was not statistically significant (P = .12). Three patients who received BMS had a clinically significant decrease in blood pressure versus 4 in the DES group (P = .33). Six patients who received BMS had a clinically significant decrease in creatinine level versus 3 in the DES group (P = 1.0). ConclusionThere is an absolute but not statistically significant difference in the incidence of restenosis requiring repeat intervention between the BMS and DES groups. No difference was detected in clinical success as measured by decreases in blood pressure or creatinine. Future larger studies are needed to corroborate these findings.

Polymer-free Drug-Coated Coronary Stents in Patients at High Bleeding Risk

BackgroundPatients at high risk for bleeding who undergo percutaneous coronary intervention (PCI) often receive bare-metal stents followed by 1 month of dual antiplatelet therapy. We studied a polymer-free and carrier-free drug-coated stent that transfers umirolimus (also known as biolimus A9), a highly lipophilic sirolimus analogue, into the vessel wall over a period of 1 month.MethodsIn a randomized, double-blind trial, we compared the drug-coated stent with a very similar bare-metal stent in patients with a high risk of bleeding who underwent PCI. All patients received 1 month of dual antiplatelet therapy. The primary safety end point, tested for both noninferiority and superiority, was a composite of cardiac death, myocardial infarction, or stent thrombosis. The primary efficacy end point was clinically driven target-lesion revascularization.ResultsWe enrolled 2466 patients. At 390 days, the primary safety end point had occurred in 112 patients (9.4%) in the drug-coated–stent group and in 154 patients (12.9%) in the bare-metal–stent group (risk difference, −3.6 percentage points; 95% confidence interval [CI], −6.1 to −1.0; hazard ratio, 0.71; 95% CI, 0.56 to 0.91; P<0.001 for noninferiority and P=0.005 for superiority). During the same time period, clinically driven target-lesion revascularization was needed in 59 patients (5.1%) in the drug-coated–stent group and in 113 patients (9.8%) in the bare-metal–stent group (risk difference, −4.8 percentage points; 95% CI, −6.9 to −2.6; hazard ratio, 0.50; 95% CI, 0.37 to 0.69; P<0.001).ConclusionsAmong patients at high risk for bleeding who underwent PCI, a polymer-free umirolimus-coated stent was superior to a bare-metal stent with respect to the primary safety and efficacy end points when used with a 1-month course of dual antiplatelet therapy. (Funded by Biosensors Europe; LEADERS FREE ClinicalTrials.gov number, NCT01623180.)

What is the optimal perioperative management of antiplatelet therapy?

What is the optimal perioperative management of antiplatelet therapy?

Tissue Factor Pathway Inhibitor-Coated Stents Inhibit Restenosis in a Rabbit Carotid Artery Model.

Our aim was to study the efficacy and safety of tissue factor pathway inhibitor (TFPI)-coated stents in inhibiting restenosis in a rabbit carotid artery model. Subculture was conducted in aorta smooth muscle cell, which was taken from male Wistar rat, and the 3-5-generation cells were taken for plasmid transfection and cytotoxicity experiment. TFPI microspheres were made of a TFPI plasmid which was enwrapped by poly-l-glutamic acid (PLGA). TFPI-coated stents (n = 7) and bare metal stents (n = 6) were implanted into prepared carotid artery stenosis model of New Zealand white rabbits. The transfection efficiency of TFPI gene and its influence on animal tissue, restenosis inhibition, and biochemical indicator were observed. Tissue factor pathway inhibitor microspheres can transfect successfully into cells, and present no cytotoxicity. Autopsy results showed no pathological changes in liver and spleen of rabbits after implanting TFPI-coated stents. TFPI gene could transfect and express successfully in vessel wall cells, and thrombus was found in some lumens of bare metal stents group after 7 day, while no such thrombus was observed in coated stents group. Degree of hyperplasia of coronary endarterectomy in bare metal stents group was evidently higher than those in coated stents group. Obvious stent restenosis was discovered only in one case in bare metal stents group (diameter stenosis ≥50%). However, no case in coated stents group showed with stent restenosis. Tissue factor pathway inhibitor-coated stents could successfully transfect TFPI gene into vessel wall cells, thereby inhibiting restenosis without obvious side effect in the rabbit carotid artery model.

Clinical outcomes in patients with ST-segment elevation myocardial infarction treated with everolimus-eluting stents versus bare-metal stents (EXAMINATION): 5-year results of a randomised trial

Data for the safety and efficacy of new-generation drug-eluting stents at long-term follow-up, and specifically in patients with ST-segment elevation myocardial infarction, are scarce. In the EXAMINATION trial, we compared everolimus-eluting stents (EES) with bare-metal stents (BMS) in an all-comer population with ST-segment elevation myocardial infarction. In this study, we assessed the 5-year outcomes of the population in the EXAMINATION trial. In the multicentre EXAMINATION trial, done in Italy, Spain, and the Netherlands, patients with ST-segment elevation myocardial infarction were randomly assigned in a 1:1 ratio to receive EES or BMS. The random allocation schedule was computer-generated and central randomisation (by telephone) was used to allocate patients in blocks of four or six, stratified by centre. Patients were masked to treatment assignment. At 5 years, we assessed the combined patient-oriented outcome of all-cause death, any myocardial infarction, or any revascularisation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00828087. 1498 patients were randomly assigned to receive either EES (n=751) or BMS (n=747). At 5 years, complete clinical follow-up data were obtained for 731 patients treated with EES and 727 treated with BMS (97% of both groups). The patient-oriented endpoint occurred in 159 (21%) patients in the EES group versus 192 (26%) in the BMS group (hazard ratio 0·80, 95% CI 0·65-0·98; p=0·033). This difference was mainly driven by a reduced rate of all-cause mortality (65 [9%] vs 88 [12%]; 0·72, 0·52-0·10; p=0·047). Our findings should be taken as a point of reference for the assessment of new bioresorbable polymer-based metallic stents or bioresorbable scaffolds in patients with ST-segment elevation myocardial infarction. Spanish Heart Foundation.

Optimal interventional strategy for the treatment of coronary in-stent restenosis.

In-stent restenosis (ISR) has been an important issue in the era of percutaneous coronary intervention (PCI) since the first bare metal stent (BMS) was applied to clinical settings. BMS substantially reduces acute vessel closure and restenosis after PCI by attenuating early arterial recoil and contraction, two major limitations of plain old balloon angioplasty (POBA). Thereby, it has been considered as a major advancement over POBA. However, ISR caused by neointimal hyperplasia after stent implantation hampers the benefit of BMS by increasing the rate of target lesion revascularization (TLR) or target vessel revascularization (TVR). With the innovation of stent technology, drug-eluting stents (DES) designed to inhibit excessive neointimal growth was produced and anticipated to reduce the incidence of ISR. Indeed, the RAVEL trial (1), a double-blind randomized study comparing sirolimus-eluting stent with its non-coated counterpart, reported no restenosis in the sirolimus stent group, and 23.4% of the patient in the BMS group developed binary restenosis (P<0.001) at 6-month follow-up. Despite of these promising results, there’s still a certain proportion of ISR occurring after DES implantation due to the expansion of indications for PCI to complex coronary lesions in high-risk patients. Meanwhile, the advent of DES brought new challenges for the interventional cardiologists, such as the higher rate of late stent thrombosis and more bleeding events due to prolonged duration of dual anti-platelet therapy (DAPT). According to the type of stents previously implanted, ISR is classified as BMS ISR and DES ISR. As the literature (2,3) mentioned, 20% to 53% BMS ISR present as unstable angina and 3.5% to 20% as myocardial infarction (MI); The proportion of DES ISR manifesting as unstable angina and MI is 16% to 66% and 1% to 20% respectively. Given the clinical and prognostic importance of ISR, the debate on the optimal strategy to prevent and treat ISR is far from over.

Optical coherence tomography study of chronic-phase vessel healing after implantation of bare metal and paclitaxel-eluting self-expanding nitinol stents in the superficial femoral artery

BackgroundThis study aimed to assess chronic-phase suppression of neointimal proliferation and arterial healing following paclitaxel-coated (PTX) and bare metal stent (BMS) implantation in the superficial femoral artery using optical coherence tomography (OCT). MethodsTwenty-five patients with 68 stents underwent an 8-month OCT follow-up. Besides standard OCT variables, neointimal characterization and frequencies of peri-strut low-intensity area (PLIA), macrophage accumulation, and in-stent thrombi were evaluated. ResultsThe mean neointimal thickness was significantly less with PTX stents (544.9±202.2μm vs. 865.0±230.6μm, p<0.0001). The covered and uncovered strut frequencies were significantly smaller and larger, respectively, in the PTX stent group vs. the BMS group (93.7% vs. 99.4%; p<0.0001, 4.0% vs. 0.4%; p<0.0001, respectively). Heterogeneous neointima was only observed in the PTX stent group (12.5% vs. 0%, p=0.017). The frequencies of PLIA and macrophage accumulation were significantly greater in the PTX stent group (87.2% vs. 67.6%, p=0.001 and 46% vs. 9.1%, p=0.003, respectively). ConclusionAfter 8 months, reduced neointimal proliferation was observed with PTX stent implantation. On the other hand, delayed arterial healing was observed compared with BMS.

Comparison of the efficacy of drug-eluting stents versus bare-metal stents for the treatment of left main coronary artery disease.

Background:Recent studies reported that percutaneous coronary intervention with stent implantation was safe and feasible for the treatment of left main coronary artery (LMCA) disease in select patients. However, it is unclear whether drug-eluting stents (DESs) have better outcomes in patients with LMCA disease compared with bare-metal stent (BMS) during long-term follow-up in Chinese populations.Methods:From a perspective multicenter registry, 1136 consecutive patients, who underwent BMS or DES implantation for unprotected LMCA stenosis, were divided into two groups: 1007 underwent DES implantation, and 129 underwent BMS implantation. The primary outcome was the rate of major adverse cardiac events (MACEs), including cardiovascular (CV) death, myocardial infarction (MI), and target lesion revascularization (TLR) at 5 years postimplantation.Results:Patients in the DES group were older and more likely to have hyperlipidemia and bifurcation lesions. They had smaller vessels and longer lesions than patients in the BMS group. In the adjusted cohort of patients, the DES group had significantly lower 5 years rates of MACE (19.4% vs. 31.8%, P = 0.022), CV death (7.0% vs. 14.7%, P = 0.045), and MI (5.4% vs. 12.4%, P = 0.049) than the BMS group. There were no significant differences in the rate of TLR (10.9% vs. 17.8%, P = 0.110) and stent thrombosis (4.7% vs. 3.9%, P = 0.758). The rates of MACE (80.6% vs. 68.2%, P = 0.023), CV death (93.0% vs. 85.3%, P = 0.045), TLR (84.5% vs. 72.1%, P = 0.014), and MI (89.9% vs. 80.6%, P = 0.029) free survival were significantly higher in the DES group than in the BMS group. When the propensity score was included as a covariate in the Cox model, the adjusted hazard ratios for the risk of CV death and MI were 0.41 (95% confidence interval [CI]: 0.21–0.63, P = 0.029) and 0.29 (95% CI: 0.08–0.92, P = 0.037), respectively.Conclusions:DES implantation was associated with more favorable clinical outcomes than BMS implantation for the treatment of LMCA disease even though there was no significant difference in the rate of TLR between the two groups.

Percutaneous coronary intervention strategies and prognosis for graft lesions following coronary artery bypass grafting.

The purpose of this study was to compare the prognosis of graft-percutaneous coronary intervention (PCI) and native vessel (NV)-PCI, drug-eluting stents (DESs) and bare-metal stents (BMSs) for the treatment of graft lesions following coronary artery bypass grafting (CABG), and to determine the risk factors for major adverse cardiac events (MACEs). A total of 289 patients who underwent PCI following CABG between August 2005 and March 2010 were retrospectively analyzed. The effects on survival were compared among patients who underwent NV- and graft-PCI, and DES and BMS implantation. Additionally, the risk factors for MACEs following PCI for graft lesions were analyzed. The findings showed that MACE-free and revascularization-free survival rates were significantly higher in the NV-PCI group compared with those in the graft-PCI group. There were 63 cases (29.0%) of MACEs in the DES group and 25 cases (52.1%) in the BMS group. In patients undergoing NV-PCI, the DES group had significantly fewer MACEs and less target vessel revascularization (TVR) than the BMS group. In patients undergoing graft-PCI, the DES group showed a tendency for fewer MACEs and a lower incidence of cardiac mortality, myocardial infarction and TVR compared with the BMS group. Diabetes, an age of >70 years and graft-PCI were independent risk factors for MACEs in patients post-PCI. It is concluded that NV-PCI has superior long-term outcomes compared with graft-PCI, and should therefore be considered as the first-line treatment for graft disease following CABG. Despite this, graft-PCI remains a viable option. DESs are the first choice for graft-PCI due to their safety and efficacy and their association with reduced mortality and MACE rate. Diabetes, older age and graft-PCI are independent risk factors for MACEs in patients post-CABG who are undergoing revascularization.