Coronary artery stents

Summary

Percutaneous coronary interventions were revolutionised by the introduction of coronary stents, which were designed to prevent many of the shortcomings of balloon angioplasty. Despite their benefits in the early phase after PCI, the initial bare metal stent devices were associated with neointimal hyperplasia due to deep arterial injury giving rise to in-stent restenosis in 20-30% of cases. The latter was one of the primary driving forces behind the development of drug-eluting stents with controlled release of anti-proliferative agents released from polymers directly immobilised on the stent surface. Early generation drug-eluting stents releasing sirolimus or paclitaxel successfully addressed the problem of neointimal hyperplasia by reducing the risk of restenosis and subsequent need of repeat target lesion revascularisation by 50-70% compared with bare metal stents in nearly all patient and lesion subsets. However, safety concerns were raised in relation to their potential to delay arterial healing and to increase the risk of very late stent thrombosis. These concerns have led to significant modifications in stent design, resulting in a broad spectrum of new-generation drug-eluting stents. These stents feature novel anti-proliferative agents with lower drug loads, modified stent platforms, and a variety of polymers - ranging from biodegradable and durable to polymer-free...