LAUSR

Background Everolimus-eluting bioresorbable vascular scaffold (BVS) (Absorb BVS; Abbott Vascular, Santa Clara, California, USA) technology emerged with the promise that late stent-related coronary events could be prevented and coronary artery vasomotion could be restored, returning the vessel to its native state, through the use of a device that dissipates over time, leaving no trace behind [1]. However, a recent meta-analysis of randomized controlled trials, with a median follow-up of 12 months, has shown unfavorable results for the Absorb BVS stent when compared with the metallic cobalt chromium everolimuseluting stent (CoCr-EES, Xience; Abbott Vascular) for definite or probable stent thrombosis (ST) or scaffold thrombosis (ScT) [odds ratio: 1.99 (95% confidence interval: 1.00–3.98), P= 0.05], with the highest risk being between 1 and 30 days after implantation [3.11 (1.24–7.82), P= 0.02] [2]. Furthermore, the Absorb II clinical trial failed in both its primary and secondary endpoints of restoring vasomotion and decreasing late lumen loss at 3 years while demonstrating significantly greater definite or probable ScT for Absorb versus CoCrEES [3]. More recently, Wykrzykowska et al. [4] reported the result of the Amsterdam Investigator-Initiated Absorb Strategy All-Comers Trial (AIDA) study that enrolled in a randomized manner 924 patients to receive Absorb BVS or CoCr-EES (921 patients). During the median follow-up of 707 days, device failure occurred in 11.7% of patients in the Absorb BVS arm and in 10.7% of patients in the CoCr-EES arm, mainly driven by definite or probable thrombosis occurring in 3.5% of patients in the Absorb BVS versus 0.9% in the CoCr-EES arm. Many meta-analyses of trials examining Absorb and CoCr-EES for 2-year outcomes have been published in the last 3 months, and not all are in favor of the Absorb BVS [5–7]. Given the consistent findings that the Absorb BVS scaffold is associated with worse outcomes when compared with metallic drug-eluting stents (DES), there is indeed a cause for concern. Although conceptually the idea of totally bioabsorbable scaffolds is appealing, we as scientists and clinicians need to understand whether such an advancement is realistic, or only a temporary setback due to limitations of the current-generation devices, or whether as a whole bioabsorbable stents will always remain a dream beyond reach. In this background, we will briefly discuss these issues from a pathological point of view.