Stent thrombosis late after implantation of first-generation drug-eluting stents: a cause for concern

Safety and efficacy of a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent for the treatment of de novo coronary lesions: two-year results from a prospective patient-level pooled analysis of TARGET trials

OBJECTIVES

We aimed to evaluate the safety and effectiveness of the novel abluminal groove-filled biodegradable polymer-coated sirolimus-eluting FIREHAWK stent (MicroPort Medical, Shanghai, China) in a large cohort of patients.

BACKGROUND

Trials on the FIREHAWK stent allowing targeted sirolimus release were not individually powered to reliably estimate low-frequency safety endpoints such as stent thrombosis (ST) or to examine long-term safety and efficacy. Additionally, the China Food and Drug Administration requires an objective performance criterion (OPC) study for new drug-eluting stents.

METHODS

The primary endpoint, target lesion failure (TLF), was defined as the composite of cardiac death, target vessel myocardial infarction (MI), or clinically indicated target lesion revascularization at 12 months. Patient-level data from 1,007 patients with de novo native coronary lesions exclusively treated with the FIREHAWK stent in the TARGET serial studies (I and II) were prospectively collected, pooled and analyzed throughout a 2-year follow-up.

RESULTS

The 12-month rate of TLF in 1,003 patients (follow-up rate, 99.6%) was 3.9% (upper 95% confidence interval (CI): 5.3%), which was significantly lower than the performance goal of 9.0% (P < 0.0001). The 24-month rates of TLF, PoCE (a composite of all-cause death, all MI, or any revascularization), and ARC definite or probable ST were 4.6%, 7.8% and 0.1%, respectively. In subgroup analysis, long lesion (≥ 30 mm) was an independent predictor of TLF within 2 years (hazard ratio [95%CI]: 2.44 [1.32, 4.53], P < 0.01).

CONCLUSIONS

This pooled, patient-level analysis indicates that the FIREHAWK stent exhibits a promising 2-year efficacy and safety profile.

Drug-eluting stents with biodegradable polymer for the treatment of patients with diabetes mellitus: clinical outcome at 2 years in a large population of patients

Objective

This study investigates the safety and efficacy of a third-generation drug-eluting stent (DES) with biodegradable polymer in the complex patient population of diabetes mellitus (DM).

Clinical trial registration

ISRCTN81649913.

Background

Percutaneous coronary interventions in patients with DM are associated with a higher incidence of death, restenosis, and stent thrombosis as compared to non-diabetic patients. The use of a DES has been shown to improve outcomes in diabetic patients.

Methods

Out of 3,067 patients, enrolled in 126 centers worldwide in the NOBORI 2 registry, 888 patients suffered from DM, 213 of them (14%) being insulin-dependent DM (IDDM). Two years’ follow-up has been completed in this study.

Results

At 1- and 2-year follow-up, 97% and 95% of the patients, respectively, were available. The reported target lesion failure (TLF) rates at 1- and 2-year follow-up were 6.0% and 7.2% in the DM group, respectively, and 3.0% and 4.2% in the non-DM group, respectively (P<0.001 for both years). Inside the DM group, the TLF rates of 9.9% and 11.7% at the 1- and 2-year follow-ups, respectively, in patients with IDDM were significantly higher than the TLF rates of 4.7% and 5.8%, respectively, in the non-IDDM subgroup (P<0.01 for both years). The rate of stent thrombosis at the 2-year follow-up was 1.0% in the DM group and 0.7% in non-DM patients. There were no cases of late, or very late stent thrombosis in IDDM patients.

Conclusion

The Nobori DES performed well in patients with DM. As expected, patients with DM, particularly those with IDDM, had worse outcomes. However, the absence of late, and very late stent thrombosis in IDDM patients merits further investigation, as this finding might have significant clinical value.

Dual antiplatelet therapy in patients with a long coronary artery lesion over 30 mm: Determinants and impact on prognosis

BACKGROUND

The ideal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) is under debate. Lesion length is a well-recognized predictor of PCI complexity and long-term outcome.

AIM

To evaluate the determinants and impact on outcome of long-term DAPT in a retrospective cohort of patients treated for a long coronary lesion.

METHODS

Patients (n=460) who underwent PCI for a long lesion (>30 mm) were divided into two groups according to antiplatelet regimen at 1 year: patients who stopped DAPT before 1 year (single antiplatelet therapy group; n=168) and patients who continued DAPT for longer than 1 year (n=292).

RESULTS

Mean lesion length was 35.7±7.1 mm. The proportion of patients who continued DAPT after 1 year was 63.5%. The main determinants of long-term DAPT were initial presentation as myocardial infarction and implantation of a drug-eluting stent. Median follow-up was 37.4 (23-51) months after the 1-year period following the index PCI. Long-term DAPT was highly associated with a lower risk of all-cause and cardiovascular mortality by multivariable analysis and after adjustment for other predictors: hazard ratios 0.11 (95% confidence interval 0.03-0.32) and 0.15 (95% confidence interval 0.04-0.62), respectively. No increase in major bleeding was noted.

CONCLUSION

In a contemporary practice, nearly two-thirds of patients who undergo PCI for a long lesion are treated with DAPT for several years. Our results suggest that long-term DAPT is beneficial in this subset of patients identified as being at high risk.

Bioresorbable scaffolds for percutaneous coronary interventions

Innovations in drug-eluting stents (DES) have substantially reduced rates of in-segment restenosis and early stent thrombosis, improving clinical outcomes following percutaneous coronary interventions (PCI). However a fixed metallic implant in a vessel wall with restored patency and residual disease remains a precipitating factor for sustained local inflammation, in-stent neo-atherosclerosis and impaired vasomotor function increasing the risk for late complications attributed to late or very late stent thrombosis and late target lesion revascularization (TLR) (late catch-up).

The quest for optimal coronary stenting continues by further innovations in stent design and by using biocompatible materials other than cobalt chromium, platinum chromium or stainless steel for engineering coronary implants. Bioresorbable scaffolds made of biodegradable polymers or biocorrodible metals with properties of transient vessel scaffolding, local drug-elution and future restoration of vessel anatomy, physiology and local hemodynamics have been recently developed. These devices have been utilized in selected clinical applications so far providing preliminary evidence of safety showing comparable performance with current generation drug-eluting stents (DES).

Herein we provide a comprehensive overview of the current status of these technologies, we elaborate on the potential benefits of transient coronary scaffolds over permanent stents in the context of vascular reparation therapy, and we further focus on the evolving challenges these devices have to overcome to compete with current generation DES. Condensed Abstract:: The quest for optimizing percutaneous coronary interventions continues by iterative innovations in device materials beyond cobalt chromium, platinum chromium or stainless steel for engineering coronary implants. Bioresorbable scaffolds made of biodegradable polymers or biocorrodible metals with properties of transient vessel scaffolding; local drug-elution and future restoration of vessel anatomy, physiology and local hemodynamics were recently developed. These devices have been utilized in selected clinical applications providing preliminary evidence of safety showing comparable intermediate term clinical outcomes with current generation drug-eluting stents.

Reduced sirolimus systemic exposure and improved bioresorbable polymer properties: new allies for the treatment of patients with coronary artery disease

This prospective, first-in-man, open-label multicenter study sought to assess the pharmacokinetics of sirolimus after Ultimaster drug-eluting stent implantation (coated with sirolimus and bioabsorbable co-polymer) in patients with de novo coronary artery disease (the TCD-10023 PK study). The primary endpoint was sirolimus concentration in peripheral whole blood at 28 days after stent implantation. In addition, safety, tolerability, therapeutic outcome and vasomotor response after stent implantation were studied. Twenty patients were enrolled in the study. Blood samples for the measurements of sirolimus concentration were collected at eight time points during first 48 h, at 7 days and 28 days after stent implantation. Patients underwent 6-month angiographic and up to 12 months clinical follow-up. At 28 days, only two of 20 patients had sirolimus concentrations above lower limit of quantification (20.0 pg/mL). The highest sirolimus blood concentration was 105 pg/mL. The median maximum concentration was 36.8 pg/mL (range 22.9-41.5 pg/mL) for stent 3.0 × 15 mm and 87.2 pg/mL (range 60.0-105.0 pg/mL) for 3 × 28 mm stent. The median systemic exposure, as measured by the area under the time-concentration curve, was 8.3 ng h/mL (range 6.47-28.0 ng h/mL). At 6 months, endothelial function was well preserved, and up to 12 months, there were no signs of sirolimus toxicity nor any other safety concerns. Our results demonstrate that implantation of Ultimaster stent resulted in almost nondetectable sirolimus in blood after 28 days. These findings were translated into exceptional safety profile, without any sign of systemic toxicity.

Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events: patient level meta-analysis

OBJECTIVES

To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents.

DESIGN

Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported.

DATA SOURCES AND STUDY SELECTION

Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients.

PRIMARY OUTCOMES

The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death.

RESULTS

The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P<0.001), and target vessel revascularisation (0.29, 0.20 to 0.41; P<0.001) at a median follow-up of 720 days. There was no significant difference in all cause death between groups (0.83, 0.65 to 1.06; P=0.14). Findings remained unchanged at multivariable regression after adjustment for the acuity of clinical syndrome (for instance, acute coronary syndrome v stable coronary artery disease), diabetes mellitus, female sex, use of glycoprotein IIb/IIIa inhibitors, and up to one year v longer duration treatment with dual antiplatelets.

CONCLUSIONS

This meta-analysis offers evidence that compared with bare metal stents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis.

[Antithrombocytic therapy and PCI. Duration of therapy after DCB/stents/scaffolds]

The duration of dual antiplatelet therapy (DAPT) after percutaneous coronary interventions (PCI) depends on the type of intervention and the clinical situation of the patient. After angioplasty alone (plain old balloon angioplasty, POBA) DAPT is not yet established but does, however, make sense to continue for 4 weeks. The duration of DAPT after placement of bare metal stents (BMS) is 4 weeks, after drug-eluting stents (DES) 6 months, after bioresorbable vascular scaffold (BVS) systems 6-12 months and after drug-coated balloon catheters (DCB) without a new implant 4 weeks.

Drug-eluting stents in unprotected left main coronary artery disease

Though coronary bypass graft surgery (CABG) has traditionally been the cornerstone of therapy in patients with unprotected left main coronary artery (ULMCA) disease, recent evidence supports the use of percutaneous coronary intervention in appropriate patients. Indeed in patients with ULMCA disease, drug-eluting stents (DES) have shown similar incidence of hard end points, fewer periprocedural complications and lower stroke rates compared with CABG, though at the cost of increased revascularization with time. Furthermore, the availability of newer efficacious and safer DES as well as improvements in diagnostic tools, percutaneous techniques and, importantly, a better patient selection, allowed percutaneous coronary intervention a viable alternative to CABG of left main-patients with low disease complexity; however, even in this interventional era characterized by efficacious DES, patients with ULMCA disease remain a challenging high-risk population where outcomes strongly depend on clinical characteristics, anatomical disease complexity and extension and operator's experience. This review summarizes the role of DES in ULMCA disease patients.

Dual modality intravascular optical coherence tomography (OCT) and near-infrared fluorescence (NIRF) imaging: a fully automated algorithm for the distance-calibration of NIRF signal intensity for quantitative molecular imaging

Intravascular optical coherence tomography (IVOCT) is a well-established method for the high-resolution investigation of atherosclerosis in vivo. Intravascular near-infrared fluorescence (NIRF) imaging is a novel technique for the assessment of molecular processes associated with coronary artery disease. Integration of NIRF and IVOCT technology in a single catheter provides the capability to simultaneously obtain co-localized anatomical and molecular information from the artery wall. Since NIRF signal intensity attenuates as a function of imaging catheter distance to the vessel wall, the generation of quantitative NIRF data requires an accurate measurement of the vessel wall in IVOCT images. Given that dual modality, intravascular OCT-NIRF systems acquire data at a very high frame-rate (>100 frames/s), a high number of images per pullback need to be analyzed, making manual processing of OCT-NIRF data extremely time consuming. To overcome this limitation, we developed an algorithm for the automatic distance-correction of dual-modality OCT-NIRF images. We validated this method by comparing automatic to manual segmentation results in 180 in vivo images from six New Zealand White rabbit atherosclerotic after indocyanine-green injection. A high Dice similarity coefficient was found (0.97 ± 0.03) together with an average individual A-line error of 22 µm (i.e., approximately twice the axial resolution of IVOCT) and a processing time of 44 ms per image. In a similar manner, the algorithm was validated using 120 IVOCT clinical images from eight different in vivo pullbacks in human coronary arteries. The results suggest that the proposed algorithm enables fully automatic visualization of dual modality OCT-NIRF pullbacks, and provides an accurate and efficient calibration of NIRF data for quantification of the molecular agent in the atherosclerotic vessel wall.

Impact of stent strut design in metallic stents and biodegradable scaffolds

Advances in the understanding of healing mechanisms after stent implantation have led to the recognition of stent strut thickness as an essential factor affecting re-endothelialization and overall long term vessel healing response after Percutaneous Coronary Interventions (PCI). Emergence of Drug-eluting stents (DESs) with anti-proliferative coating has contributed to reducing the incidence of restenosis and Target Lesion Revascularization (TVR), while progress and innovations in stent materials have in the meantime facilitated the design of newer platforms with more conformability and thinner struts, producing lesser injury and improving integration into the vessel wall. Recent advances in biodegradable metal and polymer materials now also allow for the design of fully biodegradable platforms, which are aimed at scaffolding the vessel only temporarily to prevent recoil and constrictive remodeling of the vessel during the initial period required, and are then progressively resorbed thereby avoiding the drawback of leaving an unnecessary implant permanently in the vessel. The aim of this article is to review recent evolution in stent material and stent strut design while understanding their impact on PCI outcomes. The article describes the different metallic alloys and biodegradable material properties and how these have impacted the evolution of stent strut thickness and ultimately outcomes in patients.

Dual antiplatelet therapy in patients with stable coronary artery disease in modern practice: prevalence, correlates, and impact on prognosis (from the Suivi d'une cohorte de patients COROnariens stables en region NORd-Pas-de-Calais study)

BACKGROUND

The prevalence and correlates of dual-antiplatelet therapy (DAPT) use in stable coronary artery disease (CAD) are unknown. In addition, whether prolonged DAPT may impact prognosis in stable CAD has not been studied in real-life conditions.

METHODS

We studied 3,691 patients included in a prospective registry on stable CAD. The patients were divided in 2 groups according to their antiplatelet therapy regimen at inclusion: patients treated with DAPT were compared with those treated with single-antiplatelet therapy (SAPT). The primary outcome was a composite of cardiovascular death, myocardial infarction, or stroke.

RESULTS

Altogether, 868 (24%) patients received DAPT. Factors positively associated with DAPT use were persistent angina at inclusion, body mass index, myocardial infarction since 1 to 3 years, myocardial revascularization since 1 to 3 years, multivessel CAD, prior drug-eluting stent implantation, and prior aortic or peripheral intervention. Factors negatively associated with DAPT use were age, prior coronary bypass, and left ventricular ejection fraction. The rate of the primary outcome at 2 years was similar whether patients were treated with SAPT (4.6%) or DAPT (5.5%) (P = .301). Similar rates were also observed after propensity score matching: 5.7% when treated with SAPT versus 5.5% when treated with DAPT (P = .886). The rate of bleeding was similar between groups.

CONCLUSIONS

Our study shows that a significant proportion of stable CAD patients are treated with DAPT in modern practice. Several correlates of DAPT were identified. Although no increase in bleeding was observed, our results do not support the prescription of prolonged DAPT.

Drug-eluting stents and acute myocardial infarction: A lethal combination or friends?

Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction (STEMI). First generation drug-eluting stents (DES), (sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI.

The current status of drug-coated balloons in percutaneous coronary and peripheral interventions

Through continued innovation, percutaneous treatment of coronary and peripheral stenoses has evolved rapidly since balloon angioplasty was first introduced three decades ago. Significant advances were made with the introduction of bare metal stents and subsequently drug-eluting stents, which expanded the possibility of successful revascularisation in complicated lesions. Despite these advantages, efforts are still ongoing to improve patient outcomes further. In recent years, drug-coated balloons have emerged as an exciting technology developed to overcome the limitations faced by drug-eluting stents, such as stent thrombosis and dependency on prolonged dual antiplatelet therapy, and may prove efficacious in complex subsets such as small vessels and diffuse lesions where stent results are suboptimal. Several drug-coated balloons developed for coronary and peripheral applications were evaluated recently in preclinical and clinical studies with encouraging results. Drug-coated balloons have proven effective in treating in-stent restenosis; however, there is accumulating evidence on their utility in other clinical scenarios. We present a timely review of the mechanisms of action, key preclinical studies, emerging clinical indications, current clinical trial results, and future perspectives of this novel drug-coated balloon technology as it seeks to establish its role in percutaneous intervention.

First-generation versus second-generation drug-eluting stents in current clinical practice: updated evidence from a comprehensive meta-analysis of randomised clinical trials comprising 31 379 patients

Background

First-generation drug-eluting stents (DES) have become the most widely used devices worldwide for management of coronary artery disease. As remote follow-up data were becoming available, concerns emerged in regard to their long-term safety. Second-generation DES were designed to overcome safety issues, but the results of randomised clinical trials remain conflicting.

Methods

We compared the safety and efficacy of first-generation versus second-generation Food and Drug Administration approved DES; the following devices were included: first-generation sirolimus-eluting stent (SES) and paclitaxel-eluting stents (PES); second-generation everolimus-eluting stent (EES), zotarolimus-eluting stent Endeavor and ZES-Resolute (ZES-R). Prespecified safety end points comprised ≤1 and >1 year: overall and cardiac mortality, myocardial infarction (MI), definite/definite or probable ST; efficacy end points were target lesion revascularisation and target vessel revascularisation. Composite end points were analysed as well.

Results

33 randomised controlled trials involving 31 379 patients with stable coronary artery disease or acute coronary syndrome undergoing DES implantation were retrieved. No differences in mortality among devices were found. In the overall class comparison, second-generation DES were associated with a 22% reduction of odds of MI at short-term OR 0.77 (95% CI 0.68 to 0.89) p=0.0002; EES reduced the odds of definite-probable ST compared with PES: OR 0.33 (95% CI 0.15 to 0.73) p=0.006; First-generation SES along with second-generation EES and ZES-R showed similar efficacy in decreasing the odds of repeat revascularisation.

Conclusions

Second-generation EES and ZES-R offer similar levels of efficacy compared with first-generation SES, but are more effective than PES; however, only second-generation EES significantly reduced the incidence of MI and ST, and therefore should be perceived as the safest DES to date.

A randomized, prospective, intercontinental evaluation of a bioresorbable polymer sirolimus-eluting coronary stent system: the CENTURY II (Clinical Evaluation of New Terumo Drug-Eluting Coronary Stent System in the Treatment of Patients with Coronary Artery Disease) trial

AIM

The aim of this study was to establish safety and efficacy of a new sirolimus-eluting stent with bioresorbable polymer, Ultimaster (BP-SES). Sirolimus-eluting stent with bioresorbable polymer was compared with everolimus-eluting, permanent polymer, Xience stent (PP-EES) in the frame of a CENTURY II clinical trial designed to make global clinical data compliant with regulatory requirements in Europe and Japan.

METHODS AND RESULTS

The CENTURY II is a prospective, multicentre, randomized (1 : 1), single blind, controlled, non-inferiority clinical trial conducted at 58 study sites in Japan, Europe, and Korea. A total of 1123 patients requiring a percutaneous coronary intervention (PCI) procedure, with implantation of drug-eluting stent (DES), were enrolled [total population (TP)]. Randomization of patients was stratified for the subset of patients matching requirements for DES in Japan (Cohort JR, n = 722). Baseline patient demographic and angiographic characteristics were similar in both study arms, with minimal differences between the TP and Cohort JR. The primary endpoint, freedom from target lesion failure (TLF) at 9 months-TLF [composite of cardiac death, target-vessel-related myocardial infarction (MI) and target lesion revascularization]-was 95.6% with BP-SES and 95.1% with PP-EES (Pnon-inferiority<0.0001). Composite of cardiac death and MI rate was 2.9 and 3.8% (P = 0.40) and target vessel revascularization was 4.5% with BP-SES and 4.2% with PP-EES (P = 0.77). The stent thrombosis rate was 0.9% in both arms. In Cohort JR, freedom from TLF was 95.9 and 94.6% (Pnon-inferiority < 0.0005) with BP-SES and PP-EES, respectively.

CONCLUSION

The new bioresorbable polymer sirolimus-eluting stent showed safety and efficacy profiles similar to durable polymer everolimus-eluting stent at 9-month follow-up.

STUDY REGISTRATION NUMBER

UMIN000006940.

Novel drug-eluting stents for coronary revascularization

Over the past decades, there has been significant evolution in coronary stents used in percutaneous coronary intervention. The current novel drug-eluting stents available in the United States represent significant advancements compared to angioplasty, bare-metal stents, and the first generation of drug-eluting stents (DES). The Xience everolimus-eluting stents, Promus everolimus-eluting stents, and Resolute zotarolimus-eluting stents currently demonstrate the optimal balance of safety and efficacy. Endeavor zotarolimus-eluting stents have shorter drug-elution courses, and recent evidence suggests that 3 months of dual antiplatelet therapy appears safe, making Endeavor preferred when early discontinuation of dual antiplatelet therapy is warranted. Despite these advances in stent design, the permanent polymer and metallic stent remain in the vessel wall and may precipitate sustained inflammation, persistent vasomotor dysfunction, and in-stent neo-atherosclerosis. Bioresorbable platforms with biodegradable polymers have been developed to overcome the aforementioned limitations, and the outcomes of ongoing clinical trials are eagerly anticipated to determine if these novel stents will further improve clinical outcomes.

The role of drug-eluting balloons alone or in combination with drug-eluting stents in the treatment of de novo diffuse coronary disease

OBJECTIVES

This study sought to investigate the role of drug-eluting balloons (DEB) alone or in combination with drug-eluting stents (DES) in the treatment of diffuse de novo coronary artery disease (CAD) (>25 mm).

BACKGROUND

The use of DEB in diffuse CAD, either alone or in combination with DES, offers an alternative to stenting alone. Data regarding DEB in this context are limited.

METHODS

We retrospectively evaluated all patients treated with DEB for diffuse CAD between June 2009 and October 2012. Endpoints analyzed were major adverse cardiac events, defined as all-cause death, myocardial infarction, and target vessel revascularization (TVR), as well as TVR and target lesion revascularization separately. Results were compared with those obtained from a cohort of patients with similar characteristics treated with DES alone.

RESULTS

A total of 69 patients (93 lesions) were treated with DEB ± DES, and 93 patients with DES alone (93 lesions). A high proportion of patients were diabetic (46.4% vs. 44.1%, p = 0.77). Of the DEB-treated lesions, 56.0% were treated with DEB alone, 7.4% with DEB and DES as bail out, and 36.6% with DES and DEB as part of a hybrid approach for very long disease. Outcome rates with DEB ± DES were comparable to those with DES alone at 2-year follow-up (major adverse cardiac events = 20.8% vs. 22.7%, p = 0.74; TVR = 14.8% vs. 11.5%, p = 0.44; target lesion revascularization = 9.6% vs. 9.3%, p = 0.84).

CONCLUSIONS

DEB may have a role in the treatment of diffuse de novo CAD, either alone in smaller vessels or in combination with DES in very long disease.

Safety and efficacy of biodegradable drug-eluting vs. bare metal stents: a meta-analysis from randomized trials

BACKGROUND

Biodegradable polymeric coatings have been proposed as a promising strategy to enhance biocompatibility and improve the delayed healing in the vessel. However, the efficacy and safety of biodegradable polymer drug-eluting stents (BP-DES) vs. bare metal stents (BMS) are unknown. The aim of this study was to perform a meta-analysis of randomized controlled trials (RCTs) comparing the outcomes of BP-DES vs. BMS.

METHODS AND RESULTS

PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials, until December 2013, that compared any of approved BP-DES and BMS. Efficacy endpoints were target-vessel revascularization (TVR), target-lesion revascularization (TLR) and in-stent late loss (ISLL). Safety endpoints were death, myocardial infarction (MI), definite stent thrombosis (DST). The meta-analysis included 7 RCTs with 2,409 patients. As compared with BMS, there was a significantly reduced TVR (OR [95% CI] = 0.37 [0.28-0.50]), ISLL (OR [95% CI] = -0.41 [-0.48-0.34]) and TLR (OR [95% CI] = 0.38 [0.27-0.52]) in BP-DES patients. However, there were no difference for safety outcomes between BP-DES and BMS.

CONCLUSIONS

BP-DES is more effective in reducing ISLL, TVR and TLR, as safe as standard BMS with regard to death, ST and MI. Further large RCTs with long-term follow-up are warranted to better define the relative merits of BP-DES.

Ten-year clinical follow-up after sirolimus-eluting stent implantation

BACKGROUND

Little is known on the "very" long-term incidence of major adverse cardiac events (MACE), target-lesion revascularization (TLR), target-vessel revascularization and stent thrombosis after sirolimus-eluting stent (SES) implantation. We present the first study to provide a 10-year clinical follow-up in an unselected patient population who underwent SES implantation.

METHODS AND RESULTS

We ran a systematic 10-year clinical follow-up in a series of 200 consecutive patients treated with unrestricted SES implantation between April 2002 and April 2003 in two Swiss hospitals. Outcomes and follow-up were obtained in all 200 patients. The cumulative 10-year MACE rate was 47% with all-cause death of 20%, cardiac death of 9%, myocardial infarction of 7%, TLR and target-vessel revascularization of 8% and 11% respectively. Academic Research Consortium-defined "definite and probable" stent thrombosis-rate was 2.5%. TLR risk was maximal between 3 to 6 years. New lesion revascularization increased throughout the study period.

CONCLUSION

Incidence of TLR was maximal 3 to 6 years after SES implantation and decreased thereafter. MACE and non-TLR revascularization rates steadily increased during the complete follow-up underlining the progression of coronary artery disease.

1-year clinical outcomes of diabetic patients treated with everolimus-eluting bioresorbable vascular scaffolds: a pooled analysis of the ABSORB and the SPIRIT trials

OBJECTIVES

The aim of this study was to evaluate 1-year clinical outcomes of diabetic patients treated with the Absorb bioresorbable vascular scaffold (BVS).

BACKGROUND

Clinical outcomes of diabetic patients after BVS implantation have been unreported.

METHODS

This study included 101 patients in the ABSORB Cohort B trial and the first consecutive 450 patients with 1 year of follow-up in the ABSORB EXTEND trial. A total of 136 diabetic patients were compared with 415 nondiabetic patients. In addition, 882 diabetic patients treated with everolimus-eluting metal stents (EES) in pooled data from the SPIRIT trials (SPIRIT FIRST [Clinical Trial of the Abbott Vascular XIENCE V Everolimus Eluting Coronary Stent System], SPIRIT II [A Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System], SPIRIT III [Clinical Trial of the XIENCE V Everolimus Eluting Coronary Stent System (EECSS)], SPIRIT IV Clinical Trial [Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System]) were used for the comparison by applying propensity score matching. The primary endpoint was a device-oriented composite endpoint (DoCE), including cardiac death, target vessel myocardial infarction, and target lesion revascularization at 1-year follow-up.

RESULTS

The cumulative incidence of DoCE did not differ between diabetic and nondiabetic patients treated with the BVS (3.7% vs. 5.1%, p = 0.64). Diabetic patients treated with the BVS had a similar incidence of the DoCE compared with diabetic patients treated with EES in the matched study group (3.9% for the BVS vs. 6.4% for EES, p = 0.38). There were no differences in the incidence of definite or probable scaffold/stent thrombosis (0.7% for both diabetic and nondiabetic patients with the BVS; 1.0% for diabetic patients with the BVS vs. 1.7% for diabetic patients with EES in the matched study group).

CONCLUSIONS

In the present analyses, diabetic patients treated with the BVS showed similar rates of DoCEs compared with nondiabetic patients treated with the BVS and diabetic patients treated with EES at 1-year follow-up. (ABSORB Clinical Investigation, Cohort B; NCT00856856; ABSORB EXTEND Clinical Investigation; NCT01023789; Clinical Trial of the Abbott Vascular XIENCE V Everolimus Eluting Coronary Stent System [SPIRIT FIRST]; NCT00180453; A Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System [SPIRIT II]; NCT00180310; Clinical Trial of the XIENCE V Everolimus Eluting Coronary Stent System [EECSS] [SPIRIT III]; NCT00180479; Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System [SPIRIT IV Clinical Trial]; NCT00307047).

Preclinical study of a biodegradable polymer-based stent with abluminal sirolimus release

Background

Bioabsorbable polymer stents with drug elution only on the abluminal surface may be safer than durable polymer drug-eluting stents.

Objective

To report the experimental findings with the Inspiron^TM stent - a bioabsorbable polymer-coated stent with sirolimus release from the abluminal surface only, recently approved for clinical use.

Methods

45 stents were implanted in the coronary arteries of 15 pigs. On day 28 after implantation, angiographic, intracoronary ultrasonographic and histomorphological data were collected. Five groups were analyzed: Group I (nine bare-metal stents); Group II (nine coated with bioabsorbable polymer on the luminal and abluminal surfaces); Group III (eight stents coated with bioabsorbable polymer on the abluminal surface); Group IV (nine stents with bioabsorbable polymer and sirolimus on the luminal and abluminal surfaces); and Group V (ten stents with bioabsorbable polymer and sirolimus only on the abluminal surface).

Results

The following results were observed for Groups I, II, III, IV and V, respectively: percentage stenosis of 29 ± 20; 36 ± 14; 33 ± 19; 22 ± 13 and 26 ± 15 (p = 0.443); late lumen loss (in mm) of 1.02 ± 0.60; 1.24 ± 0.48; 1.11 ± 0.54; 0.72 ± 0.44 and 0.78 ± 0.39 (p = 0.253); neointimal area (in mm²) of 2.60 ± 1.99; 2.74 ± 1.51; 2.74 ± 1.30; 1.30 ± 1.14 and 0.97 ± 0.84 (p = 0.001; Groups IV and V versus Groups I, II and III); and percentage neointimal area of 35 ± 25; 38 ± 18; 39 ± 19; 19 ± 18 and 15 ± 12 (p = 0.001; Groups IV and V versus Groups I, II and III). Injury and inflammation scores were low and with no differences between the groups.

Conclusion

The Inspiron^TM stent proved to be safe and was able to significantly inhibit the neointimal hyperplasia observed on day 28 after implantation in porcine coronary arteries.

Clinical outcomes of biodegradable polymer drug-eluting stents for percutaneous coronary intervention: an updated meta-analysis of randomized controlled trials

Biodegradable polymer drug-eluting stents (DES) are innovative concepts in the era of percutaneous coronary intervention. We systematically reviewed the latest randomized evidence on the efficacy and safety of biodegradable polymer DES as compared to durable polymer DES. MEDLINE, Embase, and the Cochrane database were searched in August 2013 for eligible randomized controlled trials (RCTs) comparing biodegradable polymer DES with durable polymer DES. Clinical outcomes of interest were mortality, myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis. A total of 20 RCTs randomizing 20 021 participants were included, of whom 11 045 were allocated to biodegradable polymer DES and 8976 to durable polymer DES. Treatment of biodegradable polymer DES was not associated with a significant reduction of any of the clinical outcomes (all-cause mortality, odds ratio [OR]: 0.94, 95% confidence interval [CI]: 0.80 to 1.10, P = 0.42; cardiovascular mortality, OR: 0.97, 95% CI: 0.79 to 1.19, P = 0.74; MI, OR: 1.07, 95% CI: 0.91 to 1.26, P = 0.41; TLR, OR: 0.87, 95% CI: 0.69 to 1.08, P = 0.20; TVR, OR: 1.05, 95% CI: 0.85 to 1.28, P = 0.67; definite/probable stent thrombosis, OR: 0.80, 95% CI: 0.59 to 1.07, P = 0.14). Current randomized data indicate that clinical efficacy and safety profiles of biodegradable polymer DES are comparable to those of durable polymer DES. Findings from large-scale studies with rigorous methodology and long follow-up duration are needed.

Modifying effect of dual antiplatelet therapy on incidence of stent thrombosis according to implanted drug-eluting stent type

AIM

To investigate the putative modifying effect of dual antiplatelet therapy (DAPT) use on the incidence of stent thrombosis at 3 years in patients randomized to Endeavor zotarolimus-eluting stent (E-ZES) or Cypher sirolimus-eluting stent (C-SES).

METHODS AND RESULTS

Of 8709 patients in PROTECT, 4357 were randomized to E-ZES and 4352 to C-SES. Aspirin was to be given indefinitely, and clopidogrel/ticlopidine for ≥ 3 months or up to 12 months after implantation. Main outcome measures were definite or probable stent thrombosis at 3 years. Multivariable Cox regression analysis was applied, with stent type, DAPT, and their interaction as the main outcome determinants. Dual antiplatelet therapy adherence remained the same in the E-ZES and C-SES groups (79.6% at 1 year, 32.8% at 2 years, and 21.6% at 3 years). We observed a statistically significant (P = 0.0052) heterogeneity in treatment effect of stent type in relation to DAPT. In the absence of DAPT, stent thrombosis was lower with E-ZES vs. C-SES (adjusted hazard ratio 0.38, 95% confidence interval 0.19, 0.75; P = 0.0056). In the presence of DAPT, no difference was found (1.18; 0.79, 1.77; P = 0.43).

CONCLUSION

A strong interaction was observed between drug-eluting stent type and DAPT use, most likely prompted by the vascular healing response induced by the implanted DES system. These results suggest that the incidence of stent thrombosis in DES trials should not be evaluated independently of DAPT use, and the optimal duration of DAPT will likely depend upon stent type (Clinicaltrials.gov number NCT00476957).

Macro- and microscale variables regulate stent haemodynamics, fibrin deposition and thrombomodulin expression

Drug eluting stents are associated with late stent thrombosis (LST), delayed healing and prolonged exposure of stent struts to blood flow. Using macroscale disturbed and undisturbed fluid flow waveforms, we numerically and experimentally determined the effects of microscale model strut geometries upon the generation of prothrombotic conditions that are mediated by flow perturbations. Rectangular cross-sectional stent strut geometries of varying heights and corresponding streamlined versions were studied in the presence of disturbed and undisturbed bulk fluid flow. Numerical simulations and particle flow visualization experiments demonstrated that the interaction of bulk fluid flow and stent struts regulated the generation, size and dynamics of the peristrut flow recirculation zones. In the absence of endothelial cells, deposition of thrombin-generated fibrin occurred primarily in the recirculation zones. When endothelium was present, peristrut expression of anticoagulant thrombomodulin (TM) was dependent on strut height and geometry. Thinner and streamlined strut geometries reduced peristrut flow recirculation zones decreasing prothrombotic fibrin deposition and increasing endothelial anticoagulant TM expression. The studies define physical and functional consequences of macro- and microscale variables that relate to thrombogenicity associated with the most current stent designs, and particularly to LST.

Duration of dual antiplatelet therapy following percutaneous coronary intervention on re-hospitalization for acute coronary syndrome

Background

The optimal duration of dual antiplatelet therapy after percutaneous coronary intervention (PCI) remains uncertain. The objective of this study was to examine the association between duration of dual antiplatelet therapy and re-hospitalization for acute coronary syndrome (ACS) in ACS patients who underwent PCI.

Methods

We identified 975 newly diagnosed ACS patients who underwent PCI between July, 2007 and June, 2009, at a medical center in Taiwan. Cox proportional hazard models were used to examine the association between duration of dual antiplatelet therapy (9 months, 12 months and 15 months) and risks of re-hospitalization for ACS.

Results

At a mean follow-up of 2.3 years, we found that use of clopidogrel for ≥ 12 months was associated with a decreased risk of re-hospitalization for ACS (adjusted HR 0.59, 95% CI 0.36-0.95; p = 0.03). However, use of clopidogrel for ≥ 15 months was not associated with a decreased risk of re-hospitalization for ACS (adjusted HR 0.57, 95% CI 0.29-1.13; p = 0.11). Similar results were found in patients who implanted drug-eluting stents (DES), for whom at least 12 months of clopidogrel therapy is especially critical.

Conclusion

The benefit of ≥ 12 months of clopidogrel use in reducing the risk of re-hospitalization for ACS was significant among ACS patients who underwent PCI and was especially critical for those who implanted DES.

A randomised comparison of a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent with a durable polymer everolimus-eluting stent: clinical and angiographic follow-up of the TARGET I trial

AIMS

The study sought to evaluate the safety and efficacy of FIREHAWK, a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent (SES) for treating patients with single de novo coronary lesions compared with the durable polymer everolimus-eluting stent (EES) XIENCE V.

METHODS AND RESULTS

A total of 458 patients with single de novo native coronary lesions ≤24 mm in length and a coronary artery ≥2.25 to ≤4.0 mm in diameter were enrolled in the TARGET I study, a prospective, randomised, non-inferiority trial. The primary endpoint was in-stent late lumen loss (LLL) at nine-month follow-up. The secondary endpoint, target lesion failure (TLF), was defined as the composite of cardiac death, target vessel myocardial infarction (TVMI), or ischaemia-driven target lesion revascularisation (iTLR). Patients were centrally randomised to treatment with either biodegradable polymer SES (n=227) or durable polymer EES (n=231). The nine-month in-stent LLL of the biodegradable polymer SES was comparable to the EES group (0.13 ± 0.24 mm vs. 0.13 ± 0.18 mm, p=0.94; difference and 95% confidence interval 0.00 [-0.04, 0.04] mm; p for non-inferiority <0.0001). Cardiac death (0.4% vs. 0.0%), TVMI (1.3% vs. 1.7%), iTLR (0.4% vs. 0.4%) and TLF (2.2% vs. 2.2%) were similar between the biodegradable polymer SES and durable polymer EES groups at 12-month follow-up (all p>0.05). No definite/probable stent thrombosis was observed in both of these groups.

CONCLUSIONS

In the multicentre TARGET I trial, the novel abluminal groove-filled biodegradable polymer SES FIREHAWK was non-inferior to the durable polymer EES XIENCE V with respect to the primary endpoint of in-stent LLL at nine months for treating patients with single de novo coronary lesions. The incidences of clinical endpoints were low in both of the stents at 12-month follow-up. (ClinicalTrials.gov identifier: NCT01196819).