Drug-eluting stents: the end of restenosis?
One of the major advancements in interventional cardiology has been the introduction of drug-eluting stents (DES). By incorporating anti-proliferative agents onto the surface of the stent, neointimal hyperplasia occurring within the stent, which is the main cause of in-stent restenosis (ISR), is markedly reduced. Stents coated with agents, like sirolimus or paclitaxel, when compared to bare metal stents (BMS), had shown remarkable reduction in binary restenosis and target vessel revascularisation (TVR) rates in large randomised clinical trials. The final hurdle of percutaneous coronary intervention (PCI) seems to have been overcome. However, there are still many uncertainties that need to be clarified. The long-term safety of DES remains a major concern; in particular, stent thrombosis and incomplete stent apposition. In the real world, there is a tendency to implant DES in smaller vessels, longer lesions, and complex lesions, as these are high risk for ISR and would yield the greatest benefit. Whether the excellent results of clinical trials of DES can be replicated in these more complex lesions is still unknown and awaits further studies. Although early experience with DES in complex lesions had shown improved results, a higher number of ISR were seen. Finally, the high cost of these devices has precluded their use in all patients undergoing PCI and deliberation among healthcare policy-makers on who should receive DES has centred not only on financial, but also legal and ethical issues. As DES has not completely eliminated ISR and not all patients can afford DES, ISR may survive the initial assault of DES, albeit considerably less in number, for now.
Wong
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Department of Cardiology, National Heart Centre, Singapore 168752.
Chan
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C
D023903:Coronary Restenosis / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D006965:Hyperplasia; D008670:Metals; D017239:Paclitaxel / Q000008:administration & dosage; D011474:Prosthesis Design; D020123:Sirolimus / Q000008:administration & dosage; D015607:Stents; D013927:Thrombosis / Q000517:prevention & control; D017539:Tunica Intima / Q000473:pathology
D008670:Metals; D017239:Paclitaxel; D020123:Sirolimus