Bioresorbable Scaffolds for Atheroregression: Understanding of Transient Scaffolding

Abstract

This review focuses on the clinical and biological features of the bioresorbable scaffolds in interventional cardiology highlighting scientific achievements and challenges of the transient scaffolding with Absorb BVS. Special attention is granted to the vascular biology pathways which, involved in the resorption of scaffold, artery remodeling and mechanisms of Glagovian atheroregression setting the stage for subsequent clinical applications. Twenty five years ago Glagov described the phenomenon of limited external elastic membrane enlargement in response to an increase in plaque burden. We believe this threshold becomes the target for development of strategies that reverse atherosclerosis, and particularly transient scaffolding has a potential to be a tool to ultimately conquer atherosclerosis.

Undiscovered pathology of transient scaffolding remains a driver of failures in clinical trials

“…However, the histopathologic signs of the excessive extracellular matrix production (including VH-IVUS signs of the fibrous metamorphosis in the lesion) with the “hardening” hyaline arteriosclerosis cause debate for a potential of the transient scaffolding for the “restoration” of the artery wall. Frankly, a hyaline deposition in the middle-size arteries is typical for aging and very benign in elderly patients[ 22 , 23 ]. The nature and structure of hyaline (nonfibrillar glycoprotein) in the case of the transient scaffolding is not entirely clear.…”

“…A large PB of > 70% is related to higher risk of MACE being a predictor of events. Half of these events were related to nonculprit lesions (PROSPECT trial, 2011)[ 22 , 23 ]. The knowledge about the window of the EEM enlargement (“Glagov threshold”[ 23 , 50 , 51 ]) might be pivotal in the selection of the optimal strategy as a target for the reduction of PB.…”

“…Half of these events were related to nonculprit lesions (PROSPECT trial, 2011)[ 22 , 23 ]. The knowledge about the window of the EEM enlargement (“Glagov threshold”[ 23 , 50 , 51 ]) might be pivotal in the selection of the optimal strategy as a target for the reduction of PB. The decrease of PAV below that threshold or upper boundary bonds the restoration of the artery geometry and local circulation amid atheroprotective reorganization of the lesion and benign progressive hyalinosis.…”

“…Low long-term event rates were shown in the ABSORB EXTEND trial. Stable lumen area (OCT-documented compensated lumen enlargement) including a partial restoration of the vasomotor function was performed in the ABSORB cohort B trial[ 17 , 23 , 25 ]. A phenomenon of the vessel wall thinning was also shown.…”

“…The running fourth industrial revolution[ 23 - 38 ] supports us with the remarkable idea of the transient scaffolding[ 39 - 51 ] and a dream of the vascular restoration therapy[ 25 ] of coronary atherosclerosis that has a potential to revolutionize cardiology providing physicians with a tackle for both to revitalize a circulation[ 20 - 36 ] in the coronary pool tailoring atheroregression[ 37 - 52 ]. Since 2006 the multimodality imaging studies of ABSORB[ 31 ] and ABSORB B[ 53 - 56 ] clinical trials that examined BVS have crashed to perform significant regression of atherosclerosis but with a trend toward absolute reduction of the percent atheroma volume (PAV) at 60 mo (at least -2.62%), which claims further research efforts.…”