Nonpolymer- and Polymer-Based Drug-Eluting Stents for Restenosis (ISAR-TEST-1)

Drug-eluting stents represent a major advance in the treatment of restenosis. They have dramatically reduced the need of repeat revascularization procedures, and, thanks to the excellent results obtained in various patient subsets, these devices are now used in almost 90% of the stent implantation procedures performed in US hospitals. Along with the increasing number of patients receiving drug-eluting stents and availability of long-term follow-up data, concern has arisen regarding the safety of these devices. At the core of this concern is the potential for increased inflammatory and thrombogenic responses and their life-threatening consequences associated with the polymers employed for the delivery of antirestenotic agents. A growing interest has been shown on polymer-free stents with a microporous surface as an alternative to stents employing polymeric coating for local drug delivery. Recently, we developed a mobile system which enables coating in the catheterization laboratory of polymeric free stents with different drug doses or combinations. Using a porcine coronary model of restenosis, we found that coating with rapamycin of a polymer-free microporous stent is feasible and effectively reduces neointimal proliferation. More recently, in a clinical study in which the efficacy of several doses of rapamycin was assessed, we showed that non-polymer coating with rapamycin is safe and leads to a dose-dependent reduction in restenosis. While the advantage deriving from the lack of polymeric cover in on-site coated rapamycin-eluting stents is readily understandable, their relative efficacy as compared with commercially available polymer-based drug-eluting stents has yet to be evaluated.

Comparison:

Polymer-free microporous stents coated with rapamycin versus standard polymer-based, paclitaxel-eluting stents