Everolimus- versus sirolimus-eluting stents for the treatment of unprotected left main coronary artery stenosis (results from the EXCELLENT registry)

Comparison of outcomes after percutaneous coronary intervention for chronic total occlusion using everolimus- versus sirolimus- versus paclitaxel-eluting stents (from the Korean National Registry of Chronic Total Occlusion Intervention)

For the treatment of chronic total occlusion (CTO), the efficacy and safety of the everolimus-eluting stent (EES) remain less well defined. Also, there are limited data for the predictors of outcome after CTO intervention. The purpose of this study was to compare clinical outcomes of the EES with the first-generation drug-eluting stent (DES) in CTO intervention and to investigate the predictors of clinical outcome. The Korean National Registry of CTO Intervention is a retrospective cohort of 26 centers from the past 5 years. The primary end point was major adverse cardiovascular events (MACE) defined as a composite of cardiac death, nonfatal myocardial infarction, and target lesion revascularization. Of the 1,754 all-comer patients, 1,509 patients (EES 311, sirolimus-eluting stent [SES] 642, paclitaxel-eluting stent 556) were finally analyzed after excluding 245 patients (mixed DESs in 46 and follow-up loss in 199). In the inverse probability weighting-adjusted population, the 1-year MACE rate of the EES was comparable with that of the SES (5.8% vs 3.4%, p = 0.796) and the paclitaxel-eluting stent (5.8% vs 6.9%, p = 0.740). Each component of MACE was also comparable among the 3 stents. Importantly, the independent predictors of MACE were diabetes mellitus, previous congestive heart failure, and left circumflex CTO. In conclusion, for the first time in the largest CTO cohort, the EES showed good 1-year clinical outcomes that were comparable with the SES. Independent predictors of MACE after CTO intervention were clinical factors (diabetes and congestive heart failure) and lesion location.

Update on percutaneous intervention for left main coronary artery stenosis

Percutaneous coronary intervention (PCI) using drug-eluting stents (DES) is currently considered as a viable alternative to coronary artery bypass graft surgery (CABG) for selected patients with left main coronary artery disease. The updated results of the landmark randomized trials comparing CABG versus PCI demonstrated comparable 5-year outcomes and are in line with the current guidelines that designate PCI as a reasonable treatment in this disease subset. Given that the completed randomized trials did not include contemporary DESs, the upcoming results of the ongoing trials evaluating the performance of new-generation DES compared with CABG (such as the EXCEL trial), may further help to clarify the current role and future recommendations of PCI for left main coronary artery disease. Apart from the recent stent technology, further improvements in outcomes after PCI may be possible when it is used with an integrated approach that combines functional concepts for decision-making, adjunctive imaging support and optimal pharmacotherapies.

Temporal Trends in Revascularization Strategy and Outcomes in Left Main Coronary Artery Stenosis

Background—

Changes over time in revascularization strategies and outcomes among patients with unprotected left main coronary artery stenosis remain largely unknown.

Methods and Results—

A total of 2618 consecutive patients with unprotected left main coronary artery stenosis who underwent revascularization were identified from the ASAN Medical Center-Left MAIN Revascularization registry and classified by time periods: bare metal stent (wave 1, 1995–1998), early drug-eluting stents (wave 2, 2003–2006), and late drug-eluting stents (wave 3, 2007–2010). Primary end point was major adverse cerebrocardiovascular events (the composite of death, myocardial infarction, repeat revascularization, and stroke). During the study period, 1124 patients underwent percutaneous coronary intervention (PCI) and 1494 patients underwent coronary artery bypass grafting. The proportion of PCI significantly increased from 35% to 52% between waves 1 and 3. In patients receiving PCI, the risk-adjusted incidence rate of major adverse cerebro-cardiovascular events decreased from 20.18 cases per 100 person-years in wave 1 to 6.77 cases per 100 person-years in wave 3 ( P <0.001 for trend). Death, the composite of death, myocardial infarction, stroke, and repeat revascularization were also significantly decreased by 40%, 35%, and 46%, respectively. The risk-adjusted incidence rate of major adverse cerebrocardiovascular events did not change in patients receiving coronary artery bypass grafting. The difference major adverse cerebrocardiovascular events risk between PCI and coronary artery bypass grafting progressively reduced (adjusted hazard ratio [95% confidence interval], 0.33 [0.23–0.47]; 0.53 [0.35–0.80]; and 1.01 [0.68–1.49] from wave 1 to wave 3.

Conclusions—

The outcomes of unprotected left main coronary artery PCI have significantly improved over time. In addition, more patients received PCI for unprotected left main coronary artery stenosis in recent years.

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.

Current application and bioavailability of drug-eluting stents

INTRODUCTION

Drug-eluting stents (DES) were developed to reduce the restenosis rate of bare metal stents (BMS) and comprises three main components: i) a metallic scaffold; ii) an antiproliferative drug to reduce or abolish the formation of the neointima; and iii) the polymer, which both enables and controls drug elution into the vessel wall. Over the years, growing evidence has been reported on the safety and efficacy for different indications of DES.

AREAS COVERED

Since the introduction of first-generation DES, the technology has been refined, including changes in the alloy, stent design, polymer, drug and drug dose. In 2014, we will usher in a third generation of DES, which will include biodegradable polymers, polymer-free DES and bioabsorbable scaffolds.

EXPERT OPINION

In recent years, considerable progress has been made in DES development. The BMS platform set the groundwork for the development of metal scaffolds with drug-eluting capability to prevent restenosis. Importantly, extensive research has shown long-term safety and efficacy of the newer generation DES. Available data suggest that DES can be safely and effectively used to treat a complex subset of patients and lesions, including patients presenting with acute myocardial infarction, lesions in saphenous vein grafts, chronic total occlusions, multivessel disease, small vessels, long lesions and bifurcations. One of the safety targets is to eliminate stent thrombosis.