With the advent of drug-eluting stents (DES), the clinical outcomes of percutaneous coronary intervention (PCI) improved dramatically. In particular, second-generation DES are characterized by thinner stent struts and improved new polymer coating, which facilitate vessel healing relative to first-generation DES. However, stent-related adverse events such as very late stent thrombosis (VLST) occur in the chronic phase even with second-generation DES. Local inflammation induced by stent struts combined with persistence of anti-proliferative drug remains an especially important nidus of late stent failure. To overcome those remaining issues, bioresorbable scaffolds (BRS) were introduced with the hope of achieving complete uncaging of the vessel wall following short-term scaffolding.

The everolimus-eluting Absorb BRS (Abbott Vascular, Santa Clara, CA, USA) is a first-generation drug-eluting BRS, composed of a poly-L-lactic acid (PLLA) backbone, with a strut thickness of 156 μm, and its efficacy and safety have been evaluated in various clinical trials. Five-year follow-up of the ABSORB Cohort B, where BRS were implanted in simple stenotic lesions indicated promising results with low restenosis and major adverse event rates [ ]. Based on the initial favorable outcome of the Absorb BRS, the next step was to compare its safety and efficacy with that of second-generation DES. In the 1-year results of the ABSORB III trial, BRS showed non-inferiority to everolimus-eluting stents (EES) with regard to target lesion failure (TLF) [ ]. However, unlike the 1-year results, the adverse event rates were higher with BVS than EES, particularly target-vessel myocardial infarction (TV-MI) and device thrombosis in the 3-year results of ABSORB III [ ]. Similarly, in ABSORB Japan, the rate of TLF at 2 years was higher in Absorb compared to the EES [ ]. In summary and contrast to earlier studies, the long-term outcomes of BRS were significantly worse compared to DES.