REWARDS- In-stent Restenosis

Drug-eluting coronary stents (DES) significantly reduced the rate of neointimal hyperplasia and in-stent restenosis (ISR) compared to bare metal stents (BMS) for the treatment of coronary artery disease. In addition, the continued evolution in scaffold and polymer design with concomitant improvements in antiplatelet therapy has improved the rates of late and very late stent thrombosis. However, despite novel metal scaffold technology, increasing operator experience, and improvement in adjunctive implantation techniques, the incidence of ISR in durable-polymer DES remains a problem, with 1-year rates as high as 12 to 15%.

The outcomes associated with ISR highlight the fact that this is by no means a benign process and studies report MI rates as high as 19.4% with one study demonstrating a total rate of death or nonfatal MI of 3.5%. In addition, ISR presenting as acute coronary syndrome (ACS) has an independent effect on major adverse cardiac events. The emergence of fully bioresorbable vascular scaffolds (BVS) has provided an exciting alternative to combat the long-term structural and functional effects on the coronary vessel seen with implantation of a permanent metal scaffold, regardless of the drug coating. Initial studies have demonstrated the non-inferiority of BVS compared to contemporary DES in regards to death, MI, and MACE. In addition, intravascular imaging has confirmed complete resorbtion of the BVS by 3 years time. The long-term benefits of such technology have yet to be fully assessed. However, based on literature outlining the complicated course of ISR in short-term and that seen in the bare metal stent era, it is projected that complete resorbtion of the vascular scaffold should improve long-term outcomes of patients with ischemic heart disease.

Currently, the clinical presentation, incidence, and outcomes of ISR in contemporary DES are not completely understood. The goal of this particular study is to retrospectively evaluate the long-term impact of ISR over a 10-year period in current contemporary DES. The data can be compared to de novo coronary artery lesions with similar characteristics and complexity to highlight the significant differences in the clinical course of each disease. Ultimately, the investigators will hopefully demonstrate the need for improvement in this arena, which the BVS will potentially provide.