Angiographic results of the first human experience with everolimus-eluting stents for the treatment of coronary lesions (the FUTURE I trial)

Cardiovascular protection associated with cilostazol, colchicine and target of rapamycin inhibitors

ABSTRACT

An alteration in extracellular matrix production by vascular smooth muscle cells is a crucial event in the pathogenesis of vascular diseases such as aging-related, atherosclerosis and allograft vasculopathy. The human target of rapamycin (TOR) is involved in the synthesis of extracellular matrix by vascular smooth muscle cells. TOR inhibitors reduce arterial stiffness, blood pressure, and left ventricle hypertrophy and decrease cardiovascular risk in kidney graft recipients and patients with coronary artery disease and heart allograft vasculopathy. Other drugs that modulate extracellular matrix production such as cilostazol and colchicine have also demonstrated a beneficial cardiovascular effect. Clinical studies have consistently shown that cilostazol confers cardiovascular protection in peripheral vascular disease, coronary artery disease, and cerebrovascular disease. In patients with type 2 diabetes, cilostazol prevents the progression of subclinical coronary atherosclerosis. Colchicine reduces arterial stiffness in patients with Familial Mediterranean Fever and patients with coronary artery disease. Pathophysiological mechanisms underlying the cardioprotective effect of these drugs may be related to interactions between the cytoskeleton, TOR signaling and cyclic AMP synthesis that remain to be fully elucidated. Adult vascular smooth muscle cells exhibit a contractile phenotype and produce little extracellular matrix. Conditions that upregulate extracellular matrix synthesis induce a phenotypic switch toward a synthetic phenotype. TOR inhibition with rapamycin reduces extracellular matrix production by promoting the change to the contractile phenotype. Cilostazol increases the cytosolic level of cyclic AMP, which in turn leads to a reduction in extracellular matrix synthesis. Colchicine is a microtubule-destabilizing agent that may enhance the synthesis of cyclic AMP.

Second generation drug-eluting stents: a focus on safety and efficacy of current devices

Introduction: Percutaneous coronary intervention (PCI) represents the most frequent procedure performed in medicine. Second generation drug eluting stents (DES) have been developed to reduce the rates of late and very late complications of first generation DES.Areas covered: To improve long-term efficacy and safety of patients undergoing PCI, second generation DES have been developed with novel stent platforms, biocompatible durable and biodegradable polymers and newer antiproliferative agents. In this review we provide an overview of second generation DES and their clinical trials, discussing safety and effectiveness of these devices, and outlining clinical indication for use.Expert commentary: Numerous clinical trials have demonstrated the safety and efficacy of second generation DES over the last decade. These devices represent the gold standard treatment in stable and acute coronary syndromes.

Drug-eluting stents versus bare-metal stents for acute coronary syndrome

BACKGROUND

Approximately 3.7 million people died from acute coronary syndrome worldwide in 2012. Acute coronary syndrome, also known as myocardial infarction or unstable angina pectoris, is caused by a sudden blockage of the blood supplied to the heart muscle. Percutaneous coronary intervention is often used for acute coronary syndrome, but previous systematic reviews on the effects of drug-eluting stents compared with bare-metal stents have shown conflicting results with regard to myocardial infarction; have not fully taken account of the risk of random and systematic errors; and have not included all relevant randomised clinical trials.

OBJECTIVES

To assess the benefits and harms of drug-eluting stents versus bare-metal stents in people with acute coronary syndrome.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, SCI-EXPANDED, and BIOSIS from their inception to January 2017. We also searched two clinical trials registers, the European Medicines Agency and the US Food and Drug Administration databases, and pharmaceutical company websites. In addition, we searched the reference lists of review articles and relevant trials.

SELECTION CRITERIA

Randomised clinical trials assessing the effects of drug-eluting stents versus bare-metal stents for acute coronary syndrome. We included trials irrespective of publication type, status, date, or language.

DATA COLLECTION AND ANALYSIS

We followed our published protocol and the methodological recommendations of Cochrane. Two review authors independently extracted data. We assessed the risks of systematic error by bias domains. We conducted Trial Sequential Analyses to control the risks of random errors. Our primary outcomes were all-cause mortality, major cardiovascular events, serious adverse events, and quality of life. Our secondary outcomes were angina, cardiovascular mortality, and myocardial infarction. Our primary assessment time point was at maximum follow-up. We assessed the quality of the evidence by the GRADE approach.

MAIN RESULTS

We included 25 trials randomising a total of 12,503 participants. All trials were at high risk of bias, and the quality of evidence according to GRADE was low to very low. We included 22 trials where the participants presented with ST-elevation myocardial infarction, 1 trial where participants presented with non-ST-elevation myocardial infarction, and 2 trials where participants presented with a mix of acute coronary syndromes.Meta-analyses at maximum follow-up showed no evidence of a difference when comparing drug-eluting stents with bare-metal stents on the risk of all-cause mortality or major cardiovascular events. The absolute risk of death was 6.97% in the drug-eluting stents group compared with 7.74% in the bare-metal stents group based on the risk ratio (RR) of 0.90 (95% confidence interval (CI) 0.78 to 1.03, 11,250 participants, 21 trials/22 comparisons, low-quality evidence). The absolute risk of a major cardiovascular event was 6.36% in the drug-eluting stents group compared with 6.63% in the bare-metal stents group based on the RR of 0.96 (95% CI 0.83 to 1.11, 10,939 participants, 19 trials/20 comparisons, very low-quality evidence). The results of Trial Sequential Analysis showed that we did not have sufficient information to confirm or reject our anticipated risk ratio reduction of 10% on either all-cause mortality or major cardiovascular events at maximum follow-up.Meta-analyses at maximum follow-up showed evidence of a benefit when comparing drug-eluting stents with bare-metal stents on the risk of a serious adverse event. The absolute risk of a serious adverse event was 18.04% in the drug-eluting stents group compared with 23.01% in the bare-metal stents group based on the RR of 0.80 (95% CI 0.74 to 0.86, 11,724 participants, 22 trials/23 comparisons, low-quality evidence), and Trial Sequential Analysis confirmed this result. When assessing each specific type of adverse event included in the serious adverse event outcome separately, the majority of the events were target vessel revascularisation. When target vessel revascularisation was analysed separately, meta-analysis showed evidence of a benefit of drug-eluting stents, and Trial Sequential Analysis confirmed this result.Meta-analyses at maximum follow-up showed no evidence of a difference when comparing drug-eluting stents with bare-metal stents on the risk of cardiovascular mortality (RR 0.91, 95% CI 0.76 to 1.09, 9248 participants, 14 trials/15 comparisons, very low-quality evidence) or myocardial infarction (RR 0.98, 95% CI 0.82 to 1.18, 10,217 participants, 18 trials/19 comparisons, very low-quality evidence). The results of the Trial Sequential Analysis showed that we had insufficient information to confirm or reject our anticipated risk ratio reduction of 10% on cardiovascular mortality and myocardial infarction.No trials reported results on quality of life or angina.

AUTHORS' CONCLUSIONS

The current evidence suggests that drug-eluting stents may lead to fewer serious adverse events compared with bare-metal stents without increasing the risk of all-cause mortality or major cardiovascular events. However, our Trial Sequential Analysis showed that there currently was not enough information to assess a risk ratio reduction of 10% for all-cause mortality, major cardiovascular events, cardiovascular mortality, or myocardial infarction, and there were no data on quality of life or angina. The evidence in this review was of low to very low quality, and the true result may depart substantially from the results presented in this review.More randomised clinical trials with low risk of bias and low risks of random errors are needed if the benefits and harms of drug-eluting stents for acute coronary syndrome are to be assessed properly. More data are needed on the outcomes all-cause mortality, major cardiovascular events, quality of life, and angina to reduce the risk of random error.

Comparative Study between Perfusion Changes and Positive Findings on Coronary Flow Reserve

BACKGROUND

Functional assessment of coronary artery obstruction is used in cardiology practice to correlate anatomic obstructions with flow decrease. Among such assessments, the study of the coronary fractional flow reserve (FFR) has become the most widely used.

OBJECTIVE

To evaluate the correlation between FFR and findings of ischemia obtained by noninvasive methods including stress echocardiography and nuclear medicine and the presence of critical coronary artery obstruction.

METHODS

Retrospective study of cases treated with systematized and standardized procedures for coronary disease between March 2011 and August 2014. We included 96 patients with 107 critical coronary obstructions (> 50% in the coronary trunk and/or ≥ 70% in other segments) estimated by quantitative coronary angiography (QCA) and intracoronary ultrasound (ICUS). All cases presented ischemia in one of the noninvasive studies.

RESULTS

All 96 patients presented ischemia (100%) in one of the functional tests. On FFR study with adenosine 140 g/kg/min, 52% of the cases had values ≤ 0.80. On correlation analysis for FFR ≤ 0.80, the evaluation of sensitivity, specificity, positive and negative predictive values, accuracy, and ROC curve in relation to the stenosis degree and length, and presence of ischemia, no significant values or strong correlation were observed.

CONCLUSION

Coronary FFR using a cut-off value of 0.80 showed no correlation with noninvasive ischemia tests in patients with severe coronary artery obstructions on QCA and ICUS.

Long-term clinical outcomes of everolimus-eluting stent versus paclitaxel-eluting stent in patients undergoing percutaneous coronary interventions: a meta-analysis

BACKGROUND

Everolimus -eluting stent (EES) is common used in patients undergoing percutaneous coronary interventions (PCI). Our purpose is to evaluate long-term clinical outcomes of everolimus -eluting stent (EES) versus paclitaxel-eluting stent (PES) in patients undergoing percutaneous coronaryinterventions (PCI) in randomized controlled trials (RCTs).

METHODS

We searched Medline, EMBASE, Cochrane Library, CNKI, VIP and relevant websites ( https://scholar-google-com.ezproxy.lib.usf.edu/ ) for articles to compare outcomes between everolimus-eluting stent and paclitaxel-eluting stent without language or date restriction. RCTs that compared the use of everolimus -eluting stent and paclitaxel-eluting stent in PCI were included. Variables relating to patient, study characteristics, and clinical endpoints were extracted. Meta-analysis was performed using RevMan 5.2 software.

RESULTS

We identified 6 published studies (from three randomized trials) more on everolimus-eluting stent (n = 3352) than paclitaxel-eluting (n = 1639), with follow-up duration ranging from 3, 4 and 5 years. Three-year outcomes of everolimus-eluting stent compared to paclitaxel-eluting were as following: the everolimus-eluting stent significantly reduced all-cause death (relative risk [RR]:0.63; 95% confidence interval [CI]: 0.46. to 0.82), MACE (RR: 0.56; 95% CI: 0.41 to 0.77), MI (RR: 0.64; 95% CI: 0.48 to 0.86), TLR (RR: 0.72; 95% CI: 0.59 to 0.88), ID-TLR (RR: 0.74; 95% CI: 0.59 to 0.92) and ST (RR: 0.54; 95% CI: 0.32 to 0.90). There was no difference in TVR between the everolimus-eluting and paclitaxel-eluting (RR: 0.76; 95% CI: 0.58 to 1.10); Four-year outcomes of everolimus-eluting compared to paclitaxel-eluting: the everolimus-eluting significantly reduced MACE (RR: 0.44; 95% CI: 0.18 to 0.98) and ID-TLR (RR: 0.47; 95 % CI: 0.23 to 0.97). There was no difference in MI (RR: 0.48; 95% CI: 0.16 to 1.46), TLR (RR: 0.46; 95% CI: 0.20 to 1.04) and ST ((RR: 0.34; 95% CI: 0.05 to 2.39). Five-year outcomes of everolimus-eluting stent compared to paclitaxel-eluting: There was no difference in ID-TLR (RR: 0.67; 95% CI: 0.45 to 1.02) and ST (RR: 0.71; 95% CI: 0.28 to 1.80).

CONCLUSIONS

In the present meta-analysis, everolimus-eluting appeared to be safe and clinically effective in patients undergoing PCI in comparison to PES in 3-year clinical outcomes; there was similar no difference in reduction of ST between EES and PES in long-term(≥ 4 years) clinical follow-ups. Everolimus-eluting is more safety than paclitaxel-eluting in long-term clinical follow-ups, whether these effects can be applied to different patient subgroups warrants further investigation.

WITHDRAWN: Drug-eluting stents versus bare metal stents for angina or acute coronary syndromes

This review 'topic' has been included in work being carried out as part of a Health Technology Assessment commissioned by the National Institute for Clinical Excellence in England and Wales. Details of this research is available via www.nice.org.uk.

The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the HTA programme, NICE, NIHR, NHS or the Department of Health.

The review has been split into 2 reviews that will be published as "Drug‐eluting stents versus bare‐metal stents for stable ischaemic heart disease" and "Drug‐eluting stents versus bare‐metal stents for acute coronary syndrome".

The editorial group responsible for this previously published document have withdrawn it from publication.

Everolimus-eluting stent platforms in percutaneous coronary intervention: comparative effectiveness and outcomes

Despite the remarkable benefits obtained following the introduction of the first-generation drug-eluting stent (DES), concerns were raised over its long-term safety, particularly with regard to very late (beyond 1 year) stent thrombosis. Newer-generation DESs have been developed to overcome this limitation using novel stent platforms, new drugs, more biocompatible durable polymers, and bioabsorbable polymers or backbones. To date, new-generation DESs have virtually replaced the use of first-generation DESs worldwide. In this review article, we discuss in detail the design, pharmacology, and mechanism of action of the newer-generation permanent and bioresorbable everolimus-eluting platforms. Furthermore, we present and evaluate the current evidence on the performance and safety of these devices compared to those of other available stent platforms.

Prevention of stent thrombosis: challenges and solutions

Stent thrombosis is an uncommon but serious complication which carries with it significant mortality and morbidity. This review analyzes the entity of stent thrombosis from a historical and clinical perspective, and chronicles the evolution of this condition through the various generations of stent development, from bare metal to first-generation, second-generation, and third-generation drug-eluting stents. It also delineates the specific risk factors associated with stent thrombosis and comprehensively examines the literature related to each of these risks. Finally, it highlights the preventative strategies that can be garnered from the existing data, and concludes that a multifactorial approach is necessary to combat the occurrence of stent thrombosis, with higher risk groups, such as patients with ST segment elevation myocardial infarction, meriting further research.

mTOR inhibitors and dyslipidemia in transplant recipients: a cause for concern?

Post-transplant dyslipidemia is exacerbated by mammalian target of rapamycin (mTOR) inhibitors. Early clinical trials of mTOR inhibitors used fixed dosing with no concomitant reduction in calcineurin inhibitor (CNI) exposure, leading to concerns when consistent and marked dyslipidemia was observed. With use of modern concentration-controlled mTOR inhibitor regimens within CNI-free or reduced-exposure CNI regimens, however, the dyslipidemic effect persists but is less pronounced. Typically, total cholesterol levels are at the upper end of normal, or indicate borderline risk, in kidney and liver transplant recipients, and are lower in heart transplant patients under near-universal statin therapy. Of note, it is possible that mTOR inhibitors may offer a cardioprotective effect. Experimental evidence for delayed progression of atherosclerosis is consistent with evidence from heart transplantation that coronary artery intimal thickening and the incidence of cardiac allograft vasculopathy are reduced with everolimus versus cyclosporine therapy. Preliminary data also indicate that mTOR inhibitors may improve arterial stiffness, a predictor of cardiovascular events, and may reduce ventricular remodeling and decrease left ventricular mass through an anti-fibrotic effect. Post-transplant dyslipidemia under mTOR inhibitor therapy should be monitored and managed closely, but unless unresponsive to therapy should not be regarded as a barrier to its use.

RAPSTROM™ first-in-man study long-term results of a biodegradable polymer sustained-release sirolimus-eluting stent in de novo coronary stenoses

BACKGROUND

Durable polymers used for first-generation drug-eluting stents (DES) potentially contribute to persistent inflammation and late DES thrombosis. We report the first real-life human experience with the rapamycin-eluting biodegradable polymer-coated Rapstrom stent.

METHODS

All consecutive patients with single de novo native coronary stenosis (<30 mm and between 2.5 and 4.0 mm) were enrolled. Major adverse cardiac events (MACE) at 1 year (cardiac death, myocardial infarction [Q and non-Q], or ischemia-driven target lesion revascularization) were the primary end-point.

RESULTS

A total of 123 patients were enrolled. The stent was implanted without complications in all patients, and no MACE were recorded at 30 days. At 12-month follow-up 9 patients (7.3%) experienced a MACE and 4 (3.2%) required a target lesion revascularization, while 1 (1%) stent thrombosis was recorded. A planned angiographic follow-up (FU) was performed in 73 patients (59%) at 9.4 ± 2.6 months following the index procedure. In-stent late loss was 0.16 ± 0.09 mm, and in-segment late loss was 0.18 ± 0.8 mm.

CONCLUSION

The Rapstrom biodegradable polymer rapamycin-eluting stent appeared safe and efficacious in this first real-life human experience, due to a low late lumen loss. Larger randomized studies are required to confirm these preliminary results.

XIENCE V everolimus-eluting coronary stent system: a novel second generation drug-eluting stent

Drug-eluting stents (DES) have been shown to be safe and significantly reduce clinical events and angiographic restenosis in the percutaneous treatment of coronary artery disease. Currently, three DES have been approved in Europe and Northern America: the sirolimus-eluting stent (SES), the paclitaxel-eluting stent (PES) and the zotarolimus-eluting stent (ZES). Everolimus, an analog of sirolimus, is an immunosuppressive and antiproliferative agent. In three studies, the SPIRIT I, FUTURE I and II, the everolimus-eluting stent has proven to be safe, well-tolerated and has shown very favorable clinical and angiographic results. Compared with earlier-generation DES, the XIENCE V everolimus-eluting coronary stent system (Advanced Cardiovascular Systems Inc., an Abbott Vascular Company, CA, USA) may provide enhanced deliverability, radiopacity with thinner strut filaments and, owing to a durable polymer, sustained drug elution and vascular compatibility.

Everolimus-eluting versus sirolimus-eluting stents in patients undergoing percutaneous coronary intervention: the EXCELLENT (Efficacy of Xience/Promus Versus Cypher to Reduce Late Loss After Stenting) randomized trial

OBJECTIVES

The goal of this study was to compare the angiographic outcomes of everolimus-eluting stents (EES) and sirolimus-eluting stents (SES) in a head-to-head manner.

BACKGROUND

EES have been shown to be superior to paclitaxel-eluting stents in inhibiting late loss (LL) and clinical outcome. Whether EES may provide similar angiographic and clinical outcomes compared with SES is undetermined.

METHODS

This was a prospective, randomized, open-label, multicenter trial to demonstrate the noninferiority of EES compared with SES in preventing LL at 9 months. A total of 1,443 patients undergoing percutaneous coronary intervention were randomized 3:1 to receive EES or SES. Routine follow-up angiography was recommended at 9 months. The primary endpoint was in-segment LL at 9 months, and major secondary endpoints included in-stent LL at 9 months, target lesion failure, cardiac death, nonfatal myocardial infarction, target lesion revascularization, and stent thrombosis at 12 months. Data were managed by an independent management center, and clinical events were adjudicated by an independent adjudication committee.

RESULTS

Clinical follow-up was available in 1,428 patients and angiographic follow-up in 924 patients (1,215 lesions). The primary endpoint of the study (in-segment LL at 9 months) was 0.11 ± 0.38 mm and 0.06 ± 0.36 mm for EES and SES, respectively (p for noninferiority = 0.0382). The in-stent LL was also noninferior (EES 0.19 ± 0.35 mm; SES 0.15 ± 0.34 mm; p for noninferiority = 0.0121). The incidence of clinical endpoints was not statistically different between the 2 groups, including target lesion failure (3.75% vs. 3.05%; p = 0.53) and stent thrombosis (0.37% vs. 0.83%; p = 0.38).

CONCLUSIONS

EES were noninferior to SES in inhibition of LL after stenting, which was corroborated by similar rates of clinical outcomes. (Efficacy of Xience/Promus Versus Cypher in Reducing Late Loss After Stenting [EXCELLENT]; NCT00698607).

Everolimus-eluting stents: update on current clinical studies

Everolimus-eluting stents (EES) have become the most commonly implanted coronary stents worldwide. This review describes and analyzes the clinical data supporting the use of EES, focusing primarily on published, randomized, controlled trials. Everolimus-eluting stents have been shown to have less restenosis, stent thrombosis, and periprocedural myocardial infarction compared with earlier generation paclitaxel-eluting stents (PES). Lower rates of adverse events for EES compared with PES were generally seen in all subgroups, with the notable exception of patients with diabetes mellitus. There have been fewer, randomized, clinical trials comparing EES with either sirolimus-eluting stents or zotarolimus-eluting stents, although very good results with EES have been observed in the trials that have been performed. Recent clinical trial data suggest that this excellent safety and efficacy profile is maintained in a next-generation EES designed to have improved mechanical properties and radiopacity.

The real world experience of the everolimus-eluting coronary stent system: audit of everolimus-eluting coronary stents

AIMS

To investigate the safety and efficacy of everolimus-eluting stents (EES) in a real world population, including those with high-risk characteristics and complex lesions.

METHODS

In this report, we analyze 2-year outcomes in 500 consecutive unselected patients treated with EES between April 2007 and March 2008. All patients were followed for 2 years for adverse events.

RESULTS

There were 995 EES deployed in 792 lesions. The indication for the coronary procedure was acute coronary syndrome in 94.2% of patients. Bifurcations were involved in 21% of lesions, 3.5% degenerated vein grafts, 2.7% left main stem stenoses, 33% multivessel disease, 4.5% in-stent restenosis, and 79.1% AHA/ACC classification B2/C lesions. The major adverse cardiac event rate (composite of cardiovascular death, acute myocardial infarction, target lesion revascularization) was 10.6%. Target lesion revascularization was required in 4.0% patients, 1.4% for in-stent thrombosis. These event rates are comparable with studies involving lower risk patients and less complex coronary lesions.

CONCLUSION

The use of EES, even in this real world, high-risk population, continues to demonstrate safety and efficacy rates comparable with current studies in more selected patient groups and, therefore, may justify current practice to utilize EES in "off label" situations.

How safe and how good are drug-eluting stents?

Percutaneous transluminal coronary angioplasty revolutionized therapy for coronary artery disease. This early promise of a viable alternative to surgical treatment of coronary artery disease was thwarted by the high rates of angiographic restenosis. The advent of stenting reduced the rates of restenosis, although it was hindered by the new problem of in-stent restenosis. It was demonstrated that in-stent restenosis was the result of a new pathology in the form of neointimal hyperplasia, which was a maladaptive healing response to bare-metal stent implantation. Recently, the introduction of drug-eluting stents (DES) technology has offered a new solution to the problem of restenosis. Current evidence suggests that although DES have reduced restenosis rates, important concerns have been raised regarding increased stent thrombosis, myocardial infarction and death. The purpose of this article is to examine the efficacy and safety data of DES as highlighted in recent publications and to further discuss the biomolecular mechanisms of accelerated endothelization and stent thrombosis. In addition, we will examine some of the newer stent technologies available.

Drug-eluting stents versus bare metal stents for angina or acute coronary syndromes

BACKGROUND

Coronary artery stents are tiny tubular devices used to 'scaffold' vessels open during percutaneous transluminal coronary angioplasty (PTCA). Restenosis (re-narrowing) of vessels treated with stents is a problem; in order to reduce restenosis, stents that elute drugs over time are now available. However these drug-eluting stents are more expensive and there is a need to assess their clinical benefits prior to recommending their use.

OBJECTIVES

To examine evidence from randomised controlled trials (RCTs) to assess the impact of drug eluting stents (DES) compared to bare metal stents (BMS) in the reduction of cardiac events.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 4), MEDLINE (1990 - April 2009) and EMBASE (1980 - January 2009) were searched. We carried out handsearching (electronic and manual) up to January 2008.

SELECTION CRITERIA

We included RCTs comparing DES with BMS used in conjunction with PTCA techniques in the review. Participants were adults with stable angina or acute coronary syndrome (ACS). We considered published and unpublished sources and included them if they reported outcome data of interest.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, assessed trial quality assessment and checked decisions within the group. Data extraction included composite event rates (major adverse cardiac event, target vessel failure); death; acute myocardial infarction (AMI); target lesion revascularisation (TLR); target vessel revascularisation (TVR) and thrombosis. Data synthesis included meta-analysis of composite event rate, death, AMI and revascularisation rates, presented as odds ratios with 95% confidence intervals (CI) using a fixed-effect model. We assessed heterogeneity between trials.

MAIN RESULTS

We included more than 14,500 patients in 47 RCTs. There were no statistically significant differences in death, AMI or thrombosis between DES and BMS. For composite events, TLR and TVR reductions were evident with use of sirolimus, paclitaxel, everolimus, dexamethasone, zotarolimus and (to a limited extent) tacrolimus-eluting stents. These effects are demonstrated in the longer term follow up. Subgroup analyses (e.g. diabetics) largely mirrored these findings.

AUTHORS' CONCLUSIONS

Drug-eluting stents releasing sirolimus, paclitaxel, dexamethasone and zotarolimus reduce composite cardiac events. However, this reduction is due largely to reductions in repeat revascularisation rates as there is no evidence of a significant effect on rates of death, MI or thrombosis. The increased cost of drug-eluting stents and lack of evidence of their cost-effectiveness means that various health funding agencies are having to limit or regulate their use in relation to price premium.

3-year clinical follow-up of the XIENCE V everolimus-eluting coronary stent system in the treatment of patients with de novo coronary artery lesions: the SPIRIT II trial (Clinical Evaluation of the Xience V Everolimus Eluting Coronary Stent System in the Treatment of Patients with de novo Native Coronary Artery Lesions)

OBJECTIVES

This paper reports the 3-year clinical outcomes of the XIENCE V (Abbott Vascular, Santa Clara, California) everolimus-eluting stent (EES) compared with the TAXUS (Boston Scientific, Natick, Massachusetts) paclitaxel-eluting stent (PES) in the randomized SPIRIT II (Clinical Evaluation of the Xience V Everolimus Eluting Coronary Stent System in the Treatment of Patients with de novo Native Coronary Artery Lesions) study.

BACKGROUND

The Xience V EES is a new-generation drug-eluting stent (DES) that might offer advantages over the first-generation DES in terms of improved clinical outcomes and a better safety profile.

METHODS

The SPIRIT II trial was a multicenter, prospective, randomized, single-blind, clinical trial, randomizing 300 patients with de novo coronary artery lesions in a ratio of 3:1 to either EES or PES. The primary end point was in-stent late loss at 180 days.

RESULTS

At 3-year clinical follow-up cardiac death was numerically lower with EES than PES (0.5% vs. 4.3%, p = 0.056). The observed rate of myocardial infarction was 3.6% for EES and 7.2% for PES (p = 0.31). The rate of ischemia-driven target lesion revascularization was 4.6% and 10.1% for EES and PES, respectively (p = 0.14). Overall, there was a trend for lower major adverse cardiovascular events in the EES group compared with PES (7.2% vs. 15.9%, p = 0.053). The rate of stent thrombosis was low and comparable in both groups (EES 1.0% vs. PES 2.9%).

CONCLUSIONS

The present study reports the favorable 3-year clinical outcomes of the EES, which are consistent with the results from other studies of the EES with shorter follow-up.

Efficacy of Xience/promus versus Cypher in rEducing Late Loss after stENTing (EXCELLENT) trial: study design and rationale of a Korean multicenter prospective randomized trial

BACKGROUND

The everolimus-eluting stent (EES) is a newly developed drug-eluting stent using the MULTILINK VISION stent platform combined with the drug everolimus contained in a polymer coating. Recently reported randomized trials have shown the noninferiority and subsequent superiority of the EES compared with the paclitaxel-eluting stent regarding in-stent late loss (LL) at 180 days. However, there have been no studies comparing head to head the EES with the sirolimus-eluting stent (SES), which has shown the least amount of LL among the previously released drug-eluting stent (DES). In addition, adjunctive antiplatelet therapy is a critical factor in optimizing long-term DES safety. Despite the recommendation of the American Heart Association/American College of Cardiology to maintain 12 months of dual antiplatelet therapy, there have been no prospective randomized trials comparing the efficacy and safety of different durations.

STUDY DESIGN

In the Efficacy of Xience/promus versus Cypher in rEducing Late Loss after stENTing (EXCELLENT) trial, approximately 1,400 patients are being prospectively and randomly assigned in a 2 x 2 factorial design according to the type of stent (EES vs SES) and the duration of dual antiplatelet therapy (6 vs 12 months). The primary end point is in-segment LL at 9 months for comparison of type of stent, and the coprimary end point is target vessel failure at 12 months for comparison of dual antiplatelet therapy duration.

SUMMARY

The EXCELLENT trial is the largest study yet performed to directly compare the efficacy and safety of the EES versus the SES. In addition, this study will also address the issue of a 6- versus 12-month duration of dual antiplatelet therapy for post-percutaneous coronary intervention management.

Novel drug eluting stent system for customised treatment of coronary lesions: CUSTOM I feasibility trial 24 month results

AIMS

The Custom NX 36 Drug Eluting Stent (DES) System is designed to treat coronary lesions via in situ stent length customisation. The stent evaluated in this study consists of nine interdigitated stent segments, each 4 mm in length, coated with a biodegradable formulation of Biolimus A9 and Poly-Lactic-Acid, a biodegradable drug carrier, and loaded into a unique sheath protected, integrated balloon delivery system.

METHODS AND RESULTS

The objective of this non-randomised prospective multicentre CUSTOM I Trial was to demonstrate the safety of in situ stent length customisation in 30 consecutive patients. Angiographic (QCA) and intravascular ultrasound (IVUS) follow-up was performed at two cohort time intervals: four (n=10) or eight (n=20) months. Mean lesion length and reference vessel diameters were 17.7 +/- 9.6 mm and 2.6 +/- 0.3 mm, respectively. Procedural success was 93%. There were three MACEs in the study population from enrollment through to twenty-four month follow-up. The in-hospital MACE rate was 2/30, with non-Q-wave myocardial infarctions events in two patients who recovered without further sequelae. At five months, one patient who had crossed over initially to PTCA required CABG surgery. Results from QCA and IVUS assessments at four and eight months showed no binary restenosis, mean in-stent late luminal loss of 0.25 +/- 0.23 mm and 0.26 +/- 0.23 mm.

CONCLUSIONS

This first evaluation of the new customisable Biolimus A9-eluting Custom NX stent suggests safety and efficacy through twenty-four month follow-up. Further evaluations are warranted to confirm the overall favourable outcomes.

Late stent malapposition risk is higher after drug-eluting stent compared with bare-metal stent implantation and associates with late stent thrombosis

AIMS

Late stent malapposition (LSM) may be acquired (LASM) or persistent. LSM may play a role in patients who develop late stent thrombosis (ST). Our objective was to compare the risk of LASM in bare metal stents (BMS) with drug-eluting stents (DES) and to investigate the possible association of both acquired and persistent LSM with (very) late ST.

METHODS AND RESULTS

We searched PubMed and relevant sources from January 2002 to December 2007. Inclusion criteria were: (a) intra-vascular ultrasonography (IVUS) at both post-stent implantation and follow-up; (b) 6-9-month-follow-up IVUS; (c) implantation of either BMS or the following DES: sirolimus, paclitaxel, everolimus, or zotarolimus; and (d) follow-up for LSM. Of 33 articles retrieved for detailed evaluation, 17 met the inclusion criteria. The risk of LASM in patients with DES was four times higher compared with BMS (OR = 4.36, CI 95% 1.74-10.94) in randomized clinical trials. The risk of (very) late ST in patients with LSM (five studies) was higher compared with those without LSM (OR = 6.51, CI 95% 1.34-34.91).

CONCLUSION

In our meta-analysis, the risk of LASM is strongly increased after DES implantation compared with BMS. Furthermore, LSM seems to be associated with late and very late ST.

Systemic exposure of everolimus after stent implantation: a pharmacokinetic study

OBJECTIVES

We evaluated the pharmacokinetics of the eluted everolimus by assessing systemic drug release and distribution of everolimus-eluting stents.

BACKGROUND

Drugs eluted by a coronary stent might cause adverse events such as tumors, infections, or noncardiac death. The systemic exposure of the drugs is unknown because there are only limited data about pharmacokinetics of drug-eluting stents in humans.

METHODS

Venous blood samples in a subset of 39 patients were drawn just before implantation of the first stent (baseline, 0-minute time point) and at 10 and 30 minutes and 1, 2, 4, 6, 12, 24, 36, 48, 72, 168, and 720 hours (30 days) after completion of implantation of the last stent. Whole blood concentrations of everolimus were determined using a sensitive validated high-performance liquid chromatography mass spectrometry/mass spectrometry method.

RESULTS

The total dose of everolimus received by the patients ranged from 53 to 588 microg. The last time point up to which whole blood concentrations could be quantified ranged per patient from 4 to 720 hours after implantation of the last stent. Across all dose levels, individual T(max) values ranged from 0.13 and 2.17 hours; individual C(max) ranged from 0.14 to 2.79 ng/mL.

CONCLUSION

This study confirms the limited exposure to the systemic circulation of the eluted drug with the use of the XIENCE V Everolimus-Eluting Coronary Stent System (Abbott Vascular, Santa Clara, CA). Therefore, a systemic cause of adverse events is unlikely.

Next-generation drug-eluting stents in coronary artery disease: focus on everolimus-eluting stent (Xience V)

Percutaneous coronary revascularization has been a mainstay in the management of coronary artery disease since its introduction in the late 1970s. Bare-metal stents and, more recently, first-generation drug-eluting stents (DES), such as sirolimus-eluting (Cypher^®) and paclitaxel-eluting stents (Taxus^®), have further improved results of percutaneous coronary intervention (PCI) by improving early results and reducing the risk of restenosis. There is currently debate on the safety of these first-generation DES, given the potential for late stent thrombosis, especially after discontinuation of dual antiplatelet therapy. There are well known caveats on the performance of their respective metallic stent platforms, delivery, and dilation systems, and polymer coatings. Second-generation DES, such as zotarolimus-eluting (Endeavor^®) and everolimus-eluting stents (Xience V^®), have recently become available in the USA and/or Europe. The Xience V stent holds the promise of superior anti-restenotic efficacy as well as long-term safety. In addition, this stent is based on the Multi-link platform and delivery system. Recently available data already suggest the superiority of the Xience V stent in comparison to the Taxus stent in terms of prevention of restenosis, without significant untoward events. Nonetheless, the number of patients studied and the follow-up duration are still too limited to enable definitive conclusions. Only indirect meta-analyses can be used to date to compare the Xience V with the Cypher. This systematic review tries to provide a concise and critical appraisal of the data in support of the Xience V everolimus-eluting stent.

A bioabsorbable everolimus-eluting coronary stent system for patients with single de-novo coronary artery lesions (ABSORB): a prospective open-label trial

BACKGROUND

A fully bioabsorbable drug-eluting coronary stent that scaffolds the vessel wall when needed and then disappears once the acute recoil and constrictive remodelling processes have subsided has theoretical advantages. The bioasorbable everolimus-eluting stent (BVS) has a backbone of poly-L-lactic acid that provides the support and a coating of poly-D,L-lactic acid that contains and controls the release of the antiproliferative agent everolimus. We assessed the feasibility and safety of this BVS stent.

METHODS

In this prospective, open-label study we enrolled 30 patients who had either stable, unstable, or silent ischaemia and a single de-novo lesion that was suitable for treatment with a single 3.0 x 12 mm or 3.0 x 18 mm stent. Patients were enrolled from four academic hospitals in Auckland, Rotterdam, Krakow, and Skejby. The composite endpoint was cardiac death, myocardial infarction, and ischaemia-driven target lesion revascularisation. Angiographic endpoints were available for 26 patients and intravascular-ultrasound endpoints for 24 patients. Clinical endpoints were assessed in all 30 patients at 6 and 12 months. In a subset of 13 patients, optical coherence tomography was undertaken at baseline and follow-up. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00300131.

FINDINGS

Procedural success was 100% (30/30 patients), and device success 94% (29/31 attempts at implantation of the stent). At 1 year, the rate of major adverse cardiac events was 3.3%, with only one patient having a non-Q wave myocardial infarction and no target lesion revascularisations. No late stent thromboses were recorded. At 6-month follow-up, the angiographic in-stent late loss was 0.44 (0.35) mm and was mainly due to a mild reduction of the stent area (-11.8%) as measured by intravascular ultrasound. The neointimal area was small (0.30 [SD 0.44] mm2), with a minimal area obstruction of 5.5%.

INTERPRETATION

This study shows the feasibility of implantation of the bioabsorbable everolimus-eluting stent, with an acceptable in-stent late loss, minimal intrastent neointimal hyperplasia, and a low stent area obstruction.

FUNDING

Abbott Vascular.

Delivery of large biopharmaceuticals from cardiovascular stents: a review

This review focuses on new and emerging large-molecule bioactive agents delivered from stent surfaces in drug-eluting stents (DESs) to inhibit vascular restenosis in the context of interventional cardiology. New therapeutic agents representing proteins, nucleic acids (small interfering RNAs and large DNA plasmids), viral delivery vectors, and even engineered cell therapies require specific delivery designs distinct from traditional smaller-molecule approaches on DESs. While small molecules are currently the clinical standard for coronary stenting, extension of the DESs to other lesion types, peripheral vasculature, and nonvasculature therapies will seek to deliver an increasingly sophisticated armada of drug types. This review describes many of the larger-molecule and biopharmaceutical approaches reported recently for stent-based delivery with the challenges associated with formulating and delivering these drug classes compared to the current small-molecule drugs. It also includes perspectives on possible future applications that may improve safety and efficacy and facilitate diversification of the DESs to other clinical applications.

The next generation of drug-eluting stents: what's on the horizon?

Drug-eluting stents have radically changed the way we treat coronary artery disease. They offer lower restenotic rates compared with the bare metal stents and this enables more challenging and complex lesions to be treated. However, there are still limitations as restenosis has not been completely abolished and there are concerns about stent thrombosis. The next generation stents offer the technology to address these pertinent issues. This review examines the new analogs of the sirolimus family and their use in novel stent platforms, including the use of biodegradable and bioabsorbable materials employed in both stents and on the polymer. "Reservoir stents" that are specially designed to contain layers of drugs in pockets with different release profiles are discussed and an insight into the emerging field of bioengineered stents is highlighted.

Six-month clinical and angiographic results of a dedicated drug-eluting stent for the treatment of coronary bifurcation narrowings

Percutaneous intervention for coronary bifurcation lesions has been associated with increased clinical complication rates compared with nonbifurcation lesions, primarily as a result of restenosis. Therefore, there is a need for new techniques. The purpose of this study was to evaluate a new drug-eluting stent and implantation technique for the treatment of de novo coronary bifurcation lesions. The Axxess Plus trial was a prospective multicenter single-arm study that enrolled 139 patients. Each patient received a self-expanding, conically shaped nickel-titanium Axxess Plus biolimus A9-eluting stent at the level of the carina. Depending on the lesion anatomy, additional nonstudy stents were placed distally if necessary. Clinical and angiographic follow-up were scheduled at 6 months after the procedure. The overall rate of target lesion revascularization was 7.5% at 6 months. A mean of 2.4 stents were implanted per patient; 51.2% of patients received a stent to the side branch, 29.4% received balloon angioplasty only, and 20.6% of side branches were not treated. In-stent late loss in the Axxess stents was 0.09 mm. Incidences of angiographic in-stent restenosis were 7.1% in the parent vessel stents and 9.2% in the group receiving stents in the side branch (7.9% excluding bare metal stents placed distal to the Axxess stent), compared with 25% for balloon angioplasty treatment and 12% for no treatment. Late stent thrombosis was observed in 3 cases, 2 of which were associated with confirmed premature cessation of antiplatelet therapy. In conclusion, the Axxess Plus conical stent effectively treats bifurcation lesions alone or in conjunction with other drug-eluting stents.

The effects of drug-eluting coronary stents

A gyógyszerkibocsátó stentek lényegesen csökkentik a stentimplantáció után kialakuló restenosis gyakoriságát, de a simaizomsejt/neointima-proliferáció gátlására alkalmazott cytostaticumok a stent endotelizációját is gátolják, késleltetik, ezért késői gyulladásos reakció és stentthrombosis is felléphet. A szerző áttekinti a gyógyszerkibocsátó és bevonat nélküli, valamint a forgalomban lévő kétféle gyógyszerkibocsátó stentek összehasonlító vizsgálatainak eredményeit. Megállapítja, hogy mindkét gyógyszerkibocsátó stent közel azonos mértékben gátolja a restenosist. A késői stentthrombosis gyakoribb gyógyszerkibocsátó, mint bevonat nélküli stentek használata után. Különösen akkor lehet ilyen szövődményre számítani, ha nem az előírásokban szereplő indikációs területen és anatómiai helyzetben használnak gyógyszerkibocsátó stenteket. A késői stentthrombosis elkerülése érdekében ragaszkodni kell az előírásos stent alkalmazáshoz, hatékonyabb és tartósabb kettős thrombocytaaggregáció-gátló kezelés, felvilágosító munka szükséges.

Progressive stent technologies: new approaches for the treatment of cardiovascular diseases

The CYPHER (Cordis, Johnson & Johnson) sirolimus-eluting stent and the TAXU (Boston Scientific) paclitaxel-eluting stent have been extensively evaluated and have been proven to be significant novel tools for the treatment of coronary artery disease. Several sirolimus derivatives have already emerged, receiving CE Mark approval. However, in the future, it is likely that drugs presently under investigation will address additional mechanisms associated with neointimal formation, either as single agents or in combination with antiproliferative compounds. Concurrently, alterations on stent platform design (helicoidal, open-closed cell), coatings (biodegradable, bioabsorbable, nanoporous) and polymers are being explored.

Angiographic results of the first human experience with the Biolimus A9 drug-eluting stent for de novo coronary lesions

This report describes angiographic findings of the first-in-human evaluation of the Biolimus A9 drug-eluting stent (Biolimus stent) in the treatment of noncomplex coronary lesions. In total, 120 patients with 122 de novo coronary lesions (2.75- to 4.00-mm vessels, < or = 24-mm lesion length) were prospectively randomized in a 2:1 ratio to receive the Biolimus stent (n = 80, 82 lesions) or the control uncoated stent (n = 40). Baseline lesion and angiographic characteristics were similar between groups. At 6-month follow-up, late lumen loss was significantly decreased with the Biolimus stent in the stent (0.26 +/- 0.43 vs 0.74 +/- 0.45 mm, p < 0.001) and in the segment (0.14 +/- 0.45 vs 0.40 +/- 0.41 mm, p = 0.004). In-stent restenosis was 3.9% in the Biolimus stent group versus 7.7% in the control group (p = 0.40). There was no exaggerated hyperplasia at the proximal and/or distal edge of the stent.

Effect of everolimus-eluting stents in different vessel sizes (from the pooled FUTURE I and II trials)

The everolimus-eluting stent (EES) has been shown to significantly decrease neointimal proliferation at 6 months compared with the bare metal stent (BMS) in patients with de novo coronary lesions. We report mid-term outcomes based on different vessel sizes in the combined FUTURE I and II trials. In the prospective, randomized, FUTURE I trial (single center) and expanded FUTURE II trial (multicenter), 106 patients (107 lesions) were randomized to EESs (n = 49 lesions) or BMSs (n = 58 lesions). Patients were categorized into 3 groups based on preprocedure reference diameter as assessed by quantitative coronary angiography (small vessel < 2.75 mm, medium vessel 2.75 to 3.25 mm, and large vessel > 3.25 mm). At 6-month follow-up, EESs decreased in-stent late lumen loss (decreased rate range of 78% to 94%), resulting in significantly larger minimum lumen area as assessed by intravascular ultrasound (increased range of 34% to 42%) compared with the BMS across all vessel sizes. There were no cases of in-stent restenosis with EESs at any vessel size but 8 cases with BMSs (5 in small vessels). No stent thrombosis, aneurysm formation, or late stent incomplete apposition was observed in any group. The EES appears to be effective for treatment of de novo coronary lesions in decreasing neointimal proliferation at 6-month follow-up compared with BMSs, regardless of vessel size.

Drug-Eluting Stents in the Treatment of Intermediate Lesions

OBJECTIVES

To address the safety and efficacy of drug-eluting stents (DES) in the treatment of intermediate lesions, we performed a pooled analysis of four randomized DES versus bare-metal stent (BMS) trials and assessed outcomes among patients with intermediate lesions.

BACKGROUND

Before the introduction of DES, intermediate coronary lesions were commonly managed based on physiologic or anatomic assessment of lesion severity. The DES may challenge this paradigm.

METHODS

The study population involved 167 of 2,478 randomized patients (6.7%) with intermediate lesions (diameter stenosis <50% [mean 44%] by quantitative coronary angiography) from the Sirolimus-coated Bx Velocity Balloon Expandable Stent in the Treatment of Patients with De Novo Coronary Artery Lesions (SIRIUS), TAXUS-IV, and the First and Second First Use to Underscore Restenosis Reduction with Everolimus (FUTURE-I and -II) trials. End points examined included early (in-hospital and 30-day) and late (1-year) major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis, and follow-up angiographic restenosis.

RESULTS

Patients with intermediate lesions randomized to DES versus BMS had low rates of 30-day MACE (1.1% vs. 4.0% respectively; p = 0.22). At one-year follow-up, patients treated with DES versus BMS had similar rates of cardiac death (0% vs. 2.7%, respectively; p = 0.11) and MI (3.4% vs. 5.4%; p = 0.49) but markedly lower rates of TVR (3.4% vs. 20.3%; p = 0.0004), MACE (5.6% vs. 25.4%; p = 0.0003), and binary angiographic restenosis (1.8% vs. 34.0%; p < 0.0001). No patient in either group developed stent thrombosis.

CONCLUSIONS

Compared with BMS, treatment of intermediate lesions with DES appears safe and results in a marked reduction in clinical and angiographic restenosis. The efficacy of DES may require a reevaluation of current treatment paradigms for intermediate lesions.