Introduction

Initial trials comparing stenting with balloon angioplasty demonstrated improved angiographic and clinical outcomes with the former.1–3 The main clinical problem with bare metal stents (BMS) became the development of in-stent restenosis.4–6 Early data suggested that drug-eluting stents (DES) could mitigate, if not abolish, this problem.7–9 Since the approval of DES, these devices have become the predominant stents used in percutaneous coronary interventions, regardless of indication. As of September 2007, the Cypher sirolimus-eluting stent (SES) (Cordis Johnson & Johnson, Miami Lakes, Fla) had been deployed in >3 million patients worldwide,10 and the millionth Taxus paclitaxel-eluting stent (PES) (Boston Scientific, Natick, Mass) was implanted as of January 2005.11 Over the past 2 years, numerous reports of very late stent thrombosis (ST) with first-generation DES have surfaced. This highly morbid complication and data suggesting that death and myocardial infarction (MI) may be more common with DES12,13 have altered the focus of trials and registries working to determine optimal DES use. There is a hope that second-generation DES will be less prone to ST as a result of differences in drug, stent design, and polymer. Medtronic, Inc (Minneapolis, Minn) presented safety and efficacy data to a public meeting of the US Food and Drug Administration (FDA) Circulatory System Devices Panel (CSDP) in October 2007 on its Endeavor zotarolimus-eluting stent (ZES), seeking approval for the indication of treating de novo native coronary lesions ≤27 mm with reference vessel diameters of 2.5 to 3.5 mm. The FDA asked the CSDP to determine whether the data presented demonstrated a reasonable level of safety and effectiveness, with clinical benefits clearly outweighing short- and long-term risks of ZES use. Important efficacy end points included ischemia-driven target lesion revascularization (TLR) or target vessel revascularization (TVR); safety end points included death, MI, and ST. The …

Benefit of Long-Term Dual Anti-Platelet Therapy in Patients Treated With Drug-Eluting Stents: From the NHLBI Dynamic Registry

The advent of percutaneous coronary intervention (PCI) as a less invasive method to coronary artery bypass graft (CABG) surgery has revolutionized the field of interventional cardiology. The use of metal stents as supporting structures, in addition to balloon angioplasty, for maintaining the patency of blocked coronary vessels was first pioneered in 1986 [1]. Before the introduction of drug-eluting stents (DES), bare-metal stents (BMS) were the mainstay in coronary stenting procedures. Indeed, coronary stenting accounted for 84.2% of all PCI procedures in 1999, and by 2005, 90% of stenting procedures were made using a DES [2].

Characteristics and prognosis of patients with angiographic stent thrombosis: comparison between drug-eluting and bare-metal stents

Safety and Efficacy Update on First-Generation Drug-Eluting Stents

Primary percutaneous coronary intervention (pPCI) has improved survival as compared to thrombolysis. Concerns still remain regarding the risk of stent thrombosis in the setting of STEMI, especially after drug-eluting stent (DES) implantation. Therefore, the aim of this study was to report on the timing of stent thrombosis (ST) with both DES and bare metal stents (BMS) and its prognostic significance in patients undergoing pPCI. The Drug-Eluting Stent in Primary Angioplasty (DESERT) cooperation is based on a pooled database including individual data of randomised trials that evaluate the long-term safety and effectiveness of DES as compared to BMS in patients undergoing pPCI for STEMI. Follow-up data were collected for 3-6 years after the procedure. ST was defined as definite or probable, based on the ARC definition. The study population consists of 6,274 STEMI patients undergoing primary angioplasty with BMS or DES. At 1201 ± 440 days, ST occurred in 267 patients (4.25%). Most of the events were acute or subacute (within 30 days) and very late (> 1 years), with different distribution between DES vs BMS. Patients with ST were more often diabetic (21.7% vs 15.1%, p=0.005), more frequently had post-procedural TIMI 0-2 flow (14.0% vs 9.3%, p = 0.01), and were less often treated with dual antiplatelet therapy at one year follow-up. Diabetes (p = 0.036), post-procedural TIMI 0-2 Flow (p = 0.013) and ischaemia time > 6 hours (p = 0.03) were independent predictors of ST. Post-procedural TIMI 0-2 flow (p = 0.001) and ischaemia time > 6 hours (p < 0.001) were independent predictors of early ST, ischaemia time > 6 hours (p = 0.05) was independent predictor of late ST, whereas diabetes (p = 0.022) and use of DES (p = 0.002) were independent predictors of very late ST. ST was associated with a significantly higher mortality (23.6% vs 6%, p < 0.001). The greatest impact on mortality was observed with subacute (40.4%) and late (20.9%) ST, as compared to acute (12.5%) and very late (9.1%) ST. ST was an independent predictor of mortality (HR [95%CI] = 3.73 [2.75-5.07], p < 0.001). In conclusion, ST occurs relatively frequently also beyond the first year for up to six years after pPCI in STEMI, with higher late occurrence rates among patients treated with first generation DES. ST after pPCI is a powerful predictor of mortality, especially subacute ST.

First-generation drug-eluting stents (DES) have dramatically reduced the rate of in-stent restenosis (ISR) and subsequent target lesion revascularization (TLR) compared with bare-metal stents (BMS) (1). However, widespread use of first-generation DES has drawn attention to several unresolved, clinically relevant issues such as late stent thrombosis (ST) and late restenosis (2). Histopathological studies of first-generation DES have revealed that a chronic reaction to components of the permanent polymer reaction may lead to the delayed arterial healing, which is associated with increased risks of late DES failure (3,4). In addition, neoatherosclerosis is suggested as another cause of very late ST and late TLR (5). To overcome these limitations, biocompatible and biodegradable polymers have been developed and equipped with second-generation DES. Recent clinical trials demonstrated that second-generation DES has the improved efficacy and safety compared with those of first-generation DES (6,7). Nevertheless, second-generation DES, as well as first-generation DES, are not immune to ISR. In fact, Cassese et al. reported a large cohort of patients with angiographic surveillance that ISR rate of second-generation DES remains higher than 10% (8). Therefore, it is important to elucidate the mechanism of ISR after second-generation DES compared with that of BMS and first-generation DES, which may play a crucial role in the newly developed DES.

Stent thrombosis with drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis

Drug-eluting stents (DES) have a major role in treating cardiovascular disease. The evolution of bare metal stents into 1st generation durable-polymer DES (DP-DES) reduced the rate of in-stent restenosis (ISR) and the need for repeat-revascularization. However, clinical outcomes showed similar rates of late stent thrombosis (ST<1 year) and higher rates of very late stent thrombosis (ST>1 year) necessitating the advent of 2nd generation more biocompatible polymer DES and biodegradable-polymer DES (BP-DES) that reduced ST rates with shorter dual anti-platelet therapy (DAPT). Despite the improvements in drugs and polymer biocompatibility for both durable and biodegradable polymers, stent thrombosis remains an issue. Doubts remain about the safety and efficacy of the more biocompatible 2nd generation durable polymers in respect to vessel inflammatory and thrombogenic response as compared to biodegradable polymers despite clinical trial and meta-analyses evidence indicating that 2nd generation DP-DES are non-inferior to BP-DES for stent thrombosis. A long-term presence of the polymer can cause inflammation and thrombogenesis. However, the cause of stent thrombosis is multi-factorial from a drug-in-polymer formulation perspective; e.g., drug release kinetics, drug physiochemical and pharmacological properties, degradation kinetics; polymer biocompatibility and hemocompatibility and coating properties. It appears that the focus should be on controlling burst release and developing more biocompatible, durable polymers, especially considering the cost of PCI utilizing biodegradable, polymer-free and bioresorbable scaffolds. This may give an insight into certain DP-DES effectiveness as compared to BP-DES for the existing clinical data and improve future stent development.

Objectives To evaluate the efficacy and safety of currently used drug eluting stents compared with each other and compared with bare metal stents in patients with diabetes.Design Mixed treatment comparison...

To the Editor: We read the article by Park et al1 about the relationship between C-reactive protein (CRP) levels and drug-eluting stent (DES) thrombosis. Interestingly, the authors found that when CRP values were incorporated into a model containing the conventional clinical, lesion, and procedural risk factors, the C statistic increased significantly for the prediction of stent thrombosis (C statistic of the multivariable model without CRP is 0.723, which increased to 0.772 with the incorporation of CRP; estimated change=0.049; P <0.05). The inflammatory response caused by percutaneous coronary intervention in stent implantation has provided a suitable clinical model to assess the …

Drug-eluting stent thrombosis: A lesson in vascular biology

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

Incidence and Predictors of Very Late (≥4 Years) Major Cardiac Adverse Events in the DESIRE (Drug-Eluting Stents in the Real World)-Late Registry

The introduction of coronary stents into clinical practice has revolutionized the treatment of coronary artery disease. However, in-stent restenosis (ISR) and stent thrombosis represent the main adverse reactions following stent implantation. Along with procedural and technical factors, individual susceptibility, in particular the inflammatory response, play an important role in the development of these complications. C-reactive protein, one of the most extensively studied inflammatory biomarkers, was found to predict the risk of ISR but not of stent thrombosis in bare-metal stent (BMS)-treated patients. On the contrary, C-reactive protein failed to predict the occurrence of ISR in drug-eluting stent (DES)-treated patients, but it appeared to predict the risk of stent thrombosis. Important differences in the pathophysiological mechanisms of adverse reactions to BMS and DES account for the differences in the prognostic value of inflammatory biomarkers. Moreover, DES polymers are responsible for late hypersensitivity allergic reactions that may lead to late ISR and stent thrombosis. Notably, a correct employment of inflammatory biomarkers may become a useful tool for identification and management of high-risk patients. In this review, the evolving role of inflammatory biomarkers in predicting adverse reactions after stent implantation is discussed, underlying therapeutic and clinical consequences for the management of patients receiving a BMS or a DES.