New-generation drug-eluting stents in patients with complex coronary artery disease: still a “work in progress”?

Treatment of complex obstructive coronary artery disease remains a challenge for physicians in practice around the globe. However, drug-eluting stent (DES) therapy represents an important breakthrough technology which has enabled cardiologists to offer percutaneous intervention to patients with complex disease patterns who were formerly precluded from such treatment due to a high rate of stent failure, mainly as a result of in-stent restenosis. Nevertheless, rates of certain adverse clinical events after stenting remain higher in patients with complex disease and in those where the indication for stenting is deemed “off-label” in comparison to patients with more straightforward disease.

Early-generation DES were associated with some important limitations, including very late stent thrombosis and late catch-up restenosis. The basis for these problems seems to be systematic delayed healing of the stented arterial segment. Although undoubtedly multifactorial in aetiology, persistent inflammatory response to the durable polymer coatings used on these stents plays a central role. However, iterative development of newer-generation DES has resulted in improved healing after stent implantation and has further improved patient outcomes with reduced rates of restenosis and stent thrombosis in comparison to early-generation DES.