Drug-Eluting Stent Restenosis: Incidence, Predictors, Mechanisms, and Treatment

Drug-eluting stents (DES) represent a major advance in percutaneous coronary intervention (PCI). Clinical trials have shown significant reductions in restenosis with both sirolimus- and paclitaxel-eluting stents, with subsequent revascularization rates in the single digit range in most studies. Predictors of restenosis and target lesion revascularization include diabetes, prior restenosis, smaller post-PCI minimal lumen diameter and complex lesion features, such as long lesions, smaller vessels, ostial lesions, and bifurcations. DES restenosis is most commonly focal (or multifocal) within the stent and less commonly is manifest as a diffuse or proliferative narrowing. The mechanisms of DES include stent under-expansion, nonuniform stent strut distribution or stent malapposition, polymer disruption due to difficult stent delivery, stent fracture, and possibly drug resistance or failure. Although only limited data are available regarding treatment of DES restenosis, reintervention appears to be associated with relatively low subsequent recurrence rates and repeat DES implantation is generally accepted as the treatment of choice for DES restenosis.