In-Stent Restenosis

Restenosis and In-stent restenosis (ISR) have been the “enemy” for interventional cardiologists for the past 40 years and many of the technical improvements in the last 20 years were aimed at reducing its occurrence: firstly, with newer generation bare metal stents, and then drug-eluting stents and in more recent years drug-coated balloons have become the default treatment for ISR.

Restenosis is defined as a reduction in lumen diameter after PCI either with or without stent implantation. In case of no-stent strategy, it usually consists in vessel remodelling and elastic recoil; otherwise it is determined by an excessive tissue proliferation in the luminal vessel of the stent called “neointimal proliferation”, or by a new-occurring atherosclerotic process called “neoatherosclerosis”.