A bioresorbable everolimus-eluting scaffold versus a metallic everolimus-eluting stent for ischaemic heart disease caused by de-novo native coronary artery lesions (ABSORB II): an interim 1-year analysis of clinical and procedural secondary outcomes from a randomised controlled trial

Stent thrombosis and restenosis: what have we learned and where are we going? The Andreas Grüntzig Lecture ESC 2014

Modern-day stenting procedures leverage advances in pharmacotherapy and device innovation. Patients treated with contemporary antiplatelet agents, peri-procedural antithrombin therapy and new-generation drug-eluting stents (DES) have excellent outcomes over the short to medium term. Indeed, coupled with the reducing costs of these devices in most countries there remain very few indications where patients should be denied treatment with standard-of-care DES therapy. The two major causes of stent failure are stent thrombosis (ST) and in-stent restenosis (ISR). The incidence of both has reduced considerably in recent years. Current clinical registries and randomized trials with broad inclusion criteria show rates of ST at or <1% after 1 year and ∼0.2-0.4% per year thereafter; rates of clinical ISR are 5% respectively. Angiographic surveillance studies in large cohorts show rates of angiographic ISR of ∼10% with new-generation DES. The advent of high-resolution intracoronary imaging has shown that in many cases of late stent failure neoatherosclerotic change within the stented segment represents a final common pathway for both thrombotic and restenotic events. In future, a better understanding of the pathogenesis of this process may translate into improved late outcomes. Moreover, the predominance of non-stent-related disease as a cause of subsequent myocardial infarction during follow-up highlights the importance of lifestyle and pharmacological interventions targeted at modification of the underlying disease process. Finally, although recent developments focus on strategies which circumvent the need for chronically indwelling stents--such as drug-coated balloons or fully bioresorbable stents-more data are needed before the wider use of these therapies can be advocated.

Prognostic significance of endothelial dysfunction in patients undergoing percutaneous coronary intervention in the era of drug-eluting stents

Background

Endothelial function is a prognostic predictor in patients undergoing percutaneous coronary intervention (PCI). However, in an era with widespread use of drug-eluting stents, the clinical relevance of endothelial dysfunction on restenosis in patients undergoing PCI has not been fully evaluated.

Methods

This study included 80 patients with stable angina pectoris. Flow-mediated dilation (FMD) of the brachial artery was examined 1 week after PCI. Patients were retrospectively followed-up for an average of 21 months after PCI. The primary endpoints included cardiac death, nonfatal myocardial infarction, stroke, coronary revascularization, and critical limb ischemia.

Results

A drug-eluting stent was used in 58 patients and a cardiovascular event was recorded in 34 patients during follow-up. The incidence of all cardiovascular diseases was significantly greater in the low FMD (median FMD <4.2 %) than the high FMD (median FMD ≥4.2 %) group (60 % vs. 25 %, p <0.01). Furthermore, the incidence of coronary revascularization was significantly higher in the low than the high FMD group (p = 0.02), while the incidence of in-stent restenosis did not differ between the two groups. Cox regression analysis showed that low FMD was an independent predictor of cardiovascular events (hazard ratio: 2.77, 95 % confidence interval: 1.23 to 6.19, p = 0.01).

Conclusions

Impaired brachial artery FMD independently predicts long-term cardiovascular events after PCI in the era of drug-eluting stents.

The Safety and Efficacy of Absorb Bioresorbable Vascular Scaffold: A Systematic Review

Bioresorbable stents are novel devices designed to overcome the long-term limitations of permanent stent implantation. The Absorb bioresorbable vascular scaffold (BVS; Abbott Vascular, Santa Clara, CA) was the first bioresorbable stent with Conformité Européenne mark approval in coronary vessels and has been the subject of multiple clinical studies. Despite its potential advantages, the safety and efficacy of BVS remain unclear. To address this, we conducted a systematic review to examine the safety and efficacy of BVS. The MEDLINE, Embase, Current Index to Nursing & Allied Health Literature (CINAHL), Cochrane, and Science Citation Index Expanded (SCIE) databases were searched for studies examining BVS safety and efficacy. Our search was restricted to studies published in English or French. Outcomes of interest include cardiac death, myocardial infarction, target-lesion revascularization, restenosis, and composite endpoints. Eleven studies met our inclusion criteria (n = 2990), which included 1 randomized controlled trial and 10 cohort studies (2 controlled). These studies varied in size (11-1189) and follow-up duration (1-60 months). The incidence of major adverse cardiac events ranged from 2.6% to 15.5%, with no statistically significant difference between BVS and control in studies that included a comparison group. Although available data are limited, current evidence is promising and suggests that the use of BVS is not associated with a significant increase in major cardiac events in the short term. Numerous randomized controlled trials are currently in progress that will further improve our understanding of the safety and efficacy of this device.

Costs and clinical outcomes for non-invasive versus invasive diagnostic approaches to patients with suspected in-stent restenosis

This study compared costs and clinical outcomes of invasive versus non-invasive diagnostic evaluations for patients with suspected in-stent restenosis (ISR) after percutaneous coronary intervention. We developed a decision model to compare 2 year diagnosis-related costs for patients who presented with suspected ISR and were evaluated by: (1) invasive coronary angiography (ICA); (2) non-invasive stress testing strategy of myocardial perfusion imaging (MPI) with referral to ICA based on MPI; (3) coronary CT angiography-based testing strategy with referral to ICA based on CCTA. Costs were modeled from the payer's perspective using 2014 Medicare rates. 56 % of patients underwent follow-up diagnostic testing over 2 years. Compared to ICA, MPI (98.6 %) and CCTA (98.1 %) exhibited lower rates of correct diagnoses. Non-invasive strategies were associated with reduced referrals to ICA and costs compared to an ICA-based strategy, with diagnostic costs lower for CCTA than MPI. Overall 2-year costs were highest for ICA for both metallic as well as BVS stents ($1656 and $1656, respectively) when compared to MPI ($1444 and $1411) and CCTA. CCTA costs differed based upon stent size and type, and were highest for metallic stents >3.0 mm followed by metallic stents <3.0 mm, BVS < 3.0 mm and BVS > 3.0 mm ($1466 vs. $1242 vs. $855 vs. $490, respectively). MPI for suspected ISR results in lower costs and rates of complications than invasive strategies using ICA while maintaining high diagnostic performance. Depending upon stent size and type, CCTA results in lower costs than MPI.

Clinical Comparison With Short-Term Follow-Up of Bioresorbable Vascular Scaffold Versus Everolimus-Eluting Stent in Primary Percutaneous Coronary Interventions

Objective of this study was to assess the clinical performance of bioresorbable vascular scaffold (BVS) compared to everolimus-eluting stent (EES) in subjects with ST-segment elevation myocardial infarction (STEMI). We included all consecutive patients with STEMI who underwent percutaneous coronary intervention (PCI) with BVS implantation in centers participating to the Italian ABSORB Prospective Registry (BVS-RAI) and PCI with EES in the same centers during the same period. The 2 groups were compared. The primary end point was patient-oriented composite end point (POCE) including cardiac death, myocardial infarction, and target lesion revascularization (TLR) at the longest available follow-up. BVS or EES thrombosis at follow-up was also evaluated. Of the 563 patients with STEMI included, 122 received BVS and 441 EES. Procedural success was obtained in 549 (97.5%) cases without significant differences between the 2 groups (BVS 99.3% vs EES 97.0%, p = 0.2). At a median of 220-day (interquartile range 178 to 369) follow-up, no significant differences were observed in terms of POCE (BVS 4.9% vs EES 7.0%, p = 0.4); death (BVS 0.8%, EES 2.0%, p = 0.4), MI (BVS 4.1%, EES 2.0%, p = 0.2), TLR (BVS 4.1%, EES 4.5%, p = 0.8), device thrombosis (BVS 2.5%, EES 1.4%, p = 0.4). All TLR cases were successfully managed with re-PCI in both groups. A propensity matching of the study populations showed no significant differences regarding POCE at the longest available follow-up (odds ratio 0.53, 0.1 to 4.3). In conclusion, in this direct prospective comparison, BVS was associated with similar clinical results compared to EES in the STEMI setting. Larger and adequately powered randomized trials are needed to fully assess the potential clinical benefit of BVS versus the current standard of care in patients with STEMI.

Bioresorbable vascular scaffold overlap evaluation with optical coherence tomography after implantation with or without enhanced stent visualization system (WOLFIE study): a two-centre prospective comparison

To assess if enhanced stent visualization (ESV)-guided implantation of overlapping bioresorbable vascular scaffold (BVS) is superior to angiography alone-guided implantation in the reduction of overlap length. WOLFIE is a two-centre prospective open study enrolling 30 patients treated with implantation of at least two overlapping BVS. In the first centre (London), BVS implantation was guided by conventional angiography, while in the second centre (Ferrara), an ESV system was systematically employed. The primary endpoint of the study was overlap length. Secondary endpoints were: stacked struts number, area, thickness, and amount of clusters. In the ESV-guided group, overlap length was significantly lower compared to angiography-guided group [0.9 (0.6-1.8) vs. 2.2 (1.3-3.2) mm, p = 0.02]. Similarly, all secondary endpoints were significantly reduced. ESV-guided implantation of overlapping BVS is safe and effective in minimizing both overlap length and number of stacked struts.

Stable coronary artery disease: revascularisation and invasive strategies

Stable coronary artery disease is the most common clinical manifestation of ischaemic heart disease and a leading cause of mortality worldwide. Myocardial revascularisation is a mainstay in the treatment of symptomatic patients or those with ischaemia-producing coronary lesions, and reduces ischaemia to a greater extent than medical treatment. Documentation of ischaemia and plaque burden is fundamental in the risk stratification of patients with stable coronary artery disease, and several invasive and non-invasive techniques are available (eg, fractional flow reserve or intravascular ultrasound) or being validated (eg, instantaneous wave-free ratio and optical coherence tomography). The use of new-generation drug-eluting stents and arterial conduits greatly improve clinical outcome in patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). PCI is feasible, safe, and effective in many patients with stable coronary artery disease who remain symptomatic despite medical treatment. In patients with multivessel and left main coronary artery disease, the decision between PCI or CABG is guided by the local Heart Team (team of different cardiovascular specialists, including non-invasive and invasive cardiologists, and cardiac surgeons), who carefully judge the possible benefits and risks inherent to PCI and CABG. In specific subsets, such as patients with diabetes and advanced, multivessel coronary artery disease, CABG remains the standard of care in view of improved protection against recurrent ischaemic adverse events.

Absorb bioresorbable vascular scaffold: What have we learned after 5 years of clinical experience?

Bioresorbable scaffolds have the potential to introduce a paradigm shift in interventional cardiology, a true anatomical and functional "vascular restoration" instead of an artificial stiff tube encased by persistent metallic foreign body. Early clinical studies using the first commercially available drug-eluting bioresorbable vascular scaffold (BVS) reported very promising safety and efficacy outcomes, comparable to best-in-class second-generation drug-eluting metal stent. To date, more than 60,000 Absorb BVSs have been implanted with only the interim analysis of one randomized trial (ABSORB II RCT) available. Recent registries have challenged the initial claim that BVS is immune from Scaffold Thrombosis (ST). However, suboptimal device expansion and insufficient intracoronary imaging guidance can explain higher than expected ST, especially in complex lesions. The aim of this review article is to critically evaluate the results of the available Absorb BVS studies and discuss the lessons learned to optimize lesion selection and implantation technique of such devices.

A novel CX3CR1 antagonist eluting stent reduces stenosis by targeting inflammation

We evaluated the therapeutic efficacy of a novel drug eluting stent (DES) inhibiting inflammation and smooth muscle cell (SMC) proliferation. We identified CX3CR1 as a targetable receptor for prevention of monocyte adhesion and inflammation and in-stent neointimal hyperplasia without interfering with stent re-endothelization. Efficacy of AZ12201182 (AZ1220), a CX3CR1 antagonist was evaluated in inhibition of monocyte attachment in vitro. A prototype AZ1220 eluting PLGA-based polymer coated stent developed with an optimal elution profile and dose of 1 μM/stent was tested over 4 weeks in a porcine model of coronary artery stenting. Polymer coated stents without AZ1220 and bare metal stents were used as controls. AZ1220 inhibited monocyte attachment to CX3CL1 in a dose dependent manner. AZ1220 eluted from polymer coated stents in an ex vivo flow system retained bioactivity in inhibiting monocyte attachment to CX3CL1. At 4 weeks following deployment, AZ1220 eluting stents significantly reduced (∼60%) in-stent stenosis compared to both bare metal and polymer only coated stents and markedly reduced peri-stent inflammation and monocyte/macrophage accumulation without affecting re-endothelization. Anti-CX3CR1 drug eluting stents potently inhibited in-stent stenosis and may offer an alternative to mTOR targeting by current DES, specifically inhibiting polymer-induced inflammatory response and SMC proliferation, while retaining an equivalent re-endothelization response to bare metal stents.

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.

Metallic zinc exhibits optimal biocompatibility for bioabsorbable endovascular stents

Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells.

Controlling drug delivery from coronary stents: are we aiming for the right targets?

In this review article, the currently employed or explored delivery concepts for local intravascular drug delivery with drug-eluting stents (DES) are discussed with a special emphasis on clinical evidence regarding the desired release profiles. Traditional concepts to control drug release from DES include diffusion through polymers, polymer degradation and erosion as well as dissolution of particulate drug. Published clinical studies do not always reveal fine mechanistic details. The long duration of release favored for DES and the short duration of release favored for drug-eluting balloons require further investigation in experimental studies and clinical trials.

Fully bioresorbable drug-eluting coronary scaffolds: A review

Following the development of stents, then drug-eluting stents (DES), bioresorbable scaffolds are proposed as a third evolution in coronary angioplasty, aiming to reduce the incidence of restenosis and stent thrombosis and to restore vascular physiology. At least 16 such devices are currently under development, but published clinical data were available for only three of them in September 2014. The first device is Abbott's BVS(®), a poly-L-lactic acid (PLLA)-based everolimus-eluting device, which has been tested in a registry and two non-randomized trials. Clinical results seem close to what is expected from a modern DES, but possibly with more post-procedural side-effects. Two randomized trials versus DES are underway. This device is already marketed in many European countries. The second device is Elixir's DESolve(®), a PLLA-based novolimus-eluting device, which has been evaluated in two single-arm trials. Results are not widely different from those expected from a DES. The third device is Biotronik's DREAMS(®), a metallic magnesium-based paclitaxel-eluting device, which has been assessed in an encouraging single-arm trial; its second version is currently undergoing evaluation in a single-arm trial. The available results suggest that the technological and clinical development of bioresorbable scaffolds is not yet complete: their possible clinical benefits are still unclear compared with third-generation DES; the impact of arterial physiology restoration has to be assessed over the long term; and their cost-effectiveness has to be established. From the perspective of a health technology assessment, there is no compelling reason to hasten the clinical use of these devices before the results of ongoing randomized controlled trials become available.

[Management of stable chronic coronary artery disease]

Stable coronary artery disease is one of the most frequent conditions encountered in cardiology. The diagnostic algorithm encompasses several steps, the first of which is a clinical assessment with an electrocardiogram (ECG) and echocardiography to determine the probability of disease. No further work-up is recommended if the probability of coronary artery disease remains below 15 %. For patients with an intermediate probability between 15 % and 85 %, noninvasive diagnostic testing for ischemia and coronary computed tomography (CT) angiography are recommended. In the case of a positive result, medicinal therapy should be started in order to lower the event risk and alleviate symptoms. Patients with large areas of inducible ischemia and patients who remain symptomatic in spite of medicinal therapy should undergo invasive angiography. Revascularization options include bypass surgery and, more liberally than previously, percutaneous coronary intervention with stent placement and must be decided on the basis of patient characteristics. Consultation in the form of a "heart team" is recommended. After revascularization, medicinal therapy must be continued on a lifelong basis. The widely practiced routine of annual ischemia testing in patients with known coronary artery disease is not enforced by current guidelines.

Outcomes and computed tomography scan follow-up of bioresorbable vascular scaffold for the percutaneous treatment of chronic total coronary artery occlusion

Everolimus-eluting bioresorbable vascular scaffold (BVS) implantation in chronic total occlusion (CTO) could provide theoretical advantages at follow-up compared with metallic stents. This study aimed to assess the feasibility of BVS use for the percutaneous treatment of CTO by analyzing clinical outcomes and patency at midterm follow-up. From February 2013 to June 2014, 42 patients with 46 CTOs were treated by BVS implantation. Once the guidewire reached the distal lumen, all the occluded segments were predilated. Postdilation was performed in all patients. A multislice computed tomography was scheduled for all patients at 6 months. The mean age was 58 ± 9 years, 41 (98%) were men and 14 (33%) diabetic. The target vessel was predominantly the left anterior descending artery (22, 48%). According to the Japanese-CTO score, 21 CTOs (46%) were difficult or very difficult. Most cases were treated with an anterograde strategy (34 lesions, 74%). A hybrid procedure with a drug-eluting stent at the distal segment was the applied treatment in 7 CTOs (15%). The mean scaffold length was 43 ± 21 mm. Technical success was achieved in 45 lesions (98%), and 1 patient (2.4%) presented a non-Q periprocedural myocardial infarction. Re-evaluation was obtained in all patients at 6 ± 1 months. Two re-occlusions and a focal restenosis were identified. After 13 ± 5 months of follow-up, there were 2 repeat revascularizations (4.8%). Neither death nor myocardial infarction was documented. In conclusion, BVS for CTO seems to be an interesting strategy with a high rate of technical success and low rate of cardiac events at midterm follow-up in selected patients.

Impact of Strut Width in Periprocedural Myocardial Infarction: A Propensity-Matched Comparison Between Bioresorbable Scaffolds and the First-Generation Sirolimus-Eluting Stent

OBJECTIVES

This study aimed to assess the clinical impact of strut width (evaluated by abluminal strut surface area [ASSA]) on periprocedural myocardial infarction (PMI) and clinical outcomes in patients treated with bioresorbable scaffolds (BRS) versus first-generation sirolimus-eluting stents (SES).

BACKGROUND

To date, there are no reports on the impact of ASSA on PMI and clinical outcomes.

METHODS

We compared the impact of ASSA on outcomes and PMI in propensity-matched patients treated with BRS and SES. The primary outcome was the incidence of major adverse cardiac events (MACE), defined as the combination of all-cause mortality, follow-up myocardial infarction, and target vessel revascularization, at 30-days and 1-year follow-ups. The secondary endpoint was the incidence of PMI.

RESULTS

After propensity-matched analysis, 499 patients (147 BRS patients vs. 352 SES patients) were evaluated. Mean ASSA was higher in patients treated with BRS versus SES (BRS: 132.3 ± 76.7 mm(2) vs. SES: 67.6 ± 48.4 mm(2), p < 0.001). MACE was not significantly different between groups (30-days MACE: BRS: 0% vs. SES: 1.4%, p = 0.16, and 1-year MACE: BRS: 15.7% vs. SES: 11.4%, p = 0.67). The incidence of PMI was significantly higher in the BRS group (BRS: 13.1% vs. SES: 7.5%, p = 0.05). Multivariable analyses indicated that treatment of left anterior descending artery and ASSA were independent predictors of PMI.

CONCLUSIONS

BRS implantation, compared with SES implantation, was associated with a higher incidence of PMI. MACE at 30 days and 1 year were not significantly different. Left anterior descending artery percutaneous coronary intervention and ASSA were independent predictors of PMI.

Appropriate use of bioresorbable vascular scaffolds in percutaneous coronary interventions: a recommendation from experienced users : A position statement on the use of bioresorbable vascular scaffolds in the Netherlands

Percutaneous coronary interventions (PCI) have become a reliable revascularisation option to treat ischaemic coronary artery disease. Drug-eluting stents (DES) are widely used as first choice devices in many procedures due to their established good medium to long term outcomes. These permanent implants, however, do not have any residual function after vascular healing following the PCI. Beyond this initial healing period, metallic stents may induce new problems, resulting in an average rate of 2 % reinterventions per year. To eliminate this potential late limitation of permanent metallic DES, bioresorbable coronary stents or ‘vascular scaffolds’ (BVS) have been developed. In a parallel publication in this journal, an overview of the current clinical performance of these scaffolds is presented. As these scaffolds are currently CE marked and commercially available in many countries and as clinical evidence is still limited, recommendations for their general usage are needed to allow successful clinical introduction.

Current status of clinically available bioresorbable scaffolds in percutaneous coronary interventions

Drug-eluting stents (DES) are widely used as first choice devices in percutaneous coronary interventions. However, certain concerns are associated with the use of DES, i.e. delayed arterial healing with a subsequent risk of neo-atherosclerosis, late stent thrombosis and hypersensitivity reactions to the DES polymer. Bioresorbable vascular scaffolds are the next step in percutaneous coronary interventions introducing the concept of supporting the natural healing process following initial intervention without leaving any foreign body materials resulting in late adverse events. The first-generation devices have shown encouraging results in multiple studies of selected patients up to the point of full bioresorption, supporting the introduction in regular patient care. During its introduction in daily clinical practice outside the previously selected patient groups, a careful approach should be followed in which outcome is continuously monitored.

Late breaking trials of 2014 in coronary artery disease: Commentary covering ACC, EuroPCR, SCAI, TCT, ESC, and AHA

With the plethora of clinical trials, it is difficult for busy interventional cardiologists to stay up to date. Therefore, the SCAI Publications Committee concisely summarizes and provides editorial commentary on the most important coronary trials from the large international meetings of 2014. The intent is to allow quick assimilation of trial results into interventional practice.

2014 update on interventional cardiology

This article reviews the most relevant publications and studies in the field of interventional cardiology in 2014. In the area of coronary interventional procedures, integrated treatment of acute coronary syndrome continues to be the subject of numerous studies that evaluate different devices and pharmacological and mechanical strategies that can be used without increasing the risk of hemorrhage or the need for reintervention. Certain anatomical substrates continue to generate a considerable number of publications, both on the outcomes with different stents and on the use of specific techniques. Bioabsorbable drug-eluting stents are used in increasingly complex lesions with promising results. The development of interventional procedures for structural heart disease continues to advance, with new evidence on percutaneously placed aortic valve prostheses, the outcome of percutaneous mitral valve repair, and the safety and efficacy of left atrial appendage occlusion. Finally, renal denervation has generated one of the major debates of the year.

Anatomical features and management of bioresorbable vascular scaffolds failure: A case series from the GHOST registry

The Absorb bioresorbable vascular scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California) promises to address some of the residual shortcomings of existing metallic stents, such as late events induced by permanent caging of the coronary vessel. Scaffold restenosis (ScR) of BVS has been poorly described so far and treatment strategies for this event remain to be codified. We report on a case series of 14 lesions in 12 patients presenting with ScR and discuss their anatomical features and management strategies. © 2015 Wiley Periodicals, Inc.

ST-segment elevation myocardial infarction – ideal scenario for bioresorbable vascular scaffold implantation?

Bioresorbable vascular scaffolds (BVS) represent a breakthrough technology for percutaneous coronary intervention (PCI). In this context, because of the unique properties of bioresorbable devices, ST-segment elevation myocardial infarction (STEMI) may represent the ideal scenario for BVS implantation. Consistently, 57% of physicians declare they currently use BVS in this group of patients. However, continuous and growing evidence on the good performance of these devices has been actually shown only in small studies with short- and mid-term follow-up. For these reasons, we need data from sufficiently large observational studies, with long-term follow-up, to confirm that BVS can deliver the same results as 2nd-generation drug-eluting stents when using an appropriate implantation technique. In this review, we discuss the potential advantages of BVS implantation in STEMI patients, together with the most recent evidence from clinical studies, highlighting safety and procedural concerns.

Twelve or 30 months of dual antiplatelet therapy after drug-eluting stents

BACKGROUND

Dual antiplatelet therapy is recommended after coronary stenting to prevent thrombotic complications, yet the benefits and risks of treatment beyond 1 year are uncertain.

METHODS

Patients were enrolled after they had undergone a coronary stent procedure in which a drug-eluting stent was placed. After 12 months of treatment with a thienopyridine drug (clopidogrel or prasugrel) and aspirin, patients were randomly assigned to continue receiving thienopyridine treatment or to receive placebo for another 18 months; all patients continued receiving aspirin. The coprimary efficacy end points were stent thrombosis and major adverse cardiovascular and cerebrovascular events (a composite of death, myocardial infarction, or stroke) during the period from 12 to 30 months. The primary safety end point was moderate or severe bleeding.

RESULTS

A total of 9961 patients were randomly assigned to continue thienopyridine treatment or to receive placebo. Continued treatment with thienopyridine, as compared with placebo, reduced the rates of stent thrombosis (0.4% vs. 1.4%; hazard ratio, 0.29 [95% confidence interval {CI}, 0.17 to 0.48]; P<0.001) and major adverse cardiovascular and cerebrovascular events (4.3% vs. 5.9%; hazard ratio, 0.71 [95% CI, 0.59 to 0.85]; P<0.001). The rate of myocardial infarction was lower with thienopyridine treatment than with placebo (2.1% vs. 4.1%; hazard ratio, 0.47; P<0.001). The rate of death from any cause was 2.0% in the group that continued thienopyridine therapy and 1.5% in the placebo group (hazard ratio, 1.36 [95% CI, 1.00 to 1.85]; P=0.05). The rate of moderate or severe bleeding was increased with continued thienopyridine treatment (2.5% vs. 1.6%, P=0.001). An elevated risk of stent thrombosis and myocardial infarction was observed in both groups during the 3 months after discontinuation of thienopyridine treatment.

CONCLUSIONS

Dual antiplatelet therapy beyond 1 year after placement of a drug-eluting stent, as compared with aspirin therapy alone, significantly reduced the risks of stent thrombosis and major adverse cardiovascular and cerebrovascular events but was associated with an increased risk of bleeding. (Funded by a consortium of eight device and drug manufacturers and others; DAPT ClinicalTrials.gov number, NCT00977938.).