Stent Thrombosis After Percutaneous Coronary Intervention: From Bare-Metal to the Last Generation of Drug-Eluting Stents.

Since their introduction in clinical practice in 1986, different types of coronary stents have been developed and become available for the treatment of coronary artery disease. Stent thrombosis (ST) is an uncommon but harmful complication after percutaneous coronary implantation, with a high occurrence of acute myocardial infarction and risk of mortality. Among several procedural and clinical predictors, the type of coronary stent is a strong determinant of ST. This article reviews the available evidence on the most used coronary stent types in the modern era and the related risk of ST.

Molecular mechanisms of in-stent restenosis and approach to therapy with eluting stents.

Restenosis is the principal drawback of percutaneous coronary procedures. Until now, the only widely accepted way to reduce restenosis rate has been the stent. However, clinical restenosis still represents the major limitation of this technology. This article summarizes recent laboratory and clinical investigations concerning the mechanisms responsible for the transmission of mitogenic signals from plasma membrane to the nucleus in vascular smooth muscle cells that determine neointima formation after stent deployment. Recent experimental data on the impact of diabetes and physical exercise on restenosis also is reviewed. Finally, the new concept of local drugs that elute directly to the site of vascular injury from coated stents and the available clinical results obtained with rapamycin or paclitaxel-eluting stents are discussed.

The present and future of drug-eluting stents.

The only widely accepted way to reduce restenosis rate after percutaneous balloon angioplasty has been the use of coronary bare metal stents, and the last decade has witnessed a prompt and widespread adoption of bare metal stents that has revolutionized the field of interventional cardiology. The new millennium has seen the recent development of drug-eluting stents (DES), allowing controlled release of a drug directly to the injured artery, which seem to have prevented by large the problem of in-stent restenosis. The goal of this review was to summarize recent laboratory and clinical investigations concerning the effects of DES in various settings relevant to coronary heart disease. In the experimental setting, we examine the intracellular signaling and the role of smooth muscle cells after vascular injury. We also discuss recent observations from our laboratory showing the effects of coating per se on cell apoptosis and proliferation. In the clinical setting, the effects of DES in patients with stable or unstable angina pectoris is examined in detail for the relevant implications both in the treatment and prognosis. The results of a meta-analysis on the effects that have been overlooked in individual studies are reported which show a striking reduction in bypass surgery after DES implantation. Finally, we discuss the potential role of new materials and technologies (i.e., nanotechnology) that will improve DES performance allowing other future clinical applications in patients with ST-elevation myocardial infarction, vulnerable plaques, insulin-dependent diabetes mellitus, etc.