Intravascular imaging to evaluate acute and long-term performance of bioresorbable vascular scaffold

In the field of interventional cardiology, the era of vascular reparative therapy has started with the advent of fully bioresorbable devices. The new “rosy” prophecy was that this technology would provide the ultimate solution to the problem of metallic stents, and that this rose would not have any thorns. However, long-term follow-up data of the leading bioresorbable vascular scaffold (Absorb; Abbott Vascular) is becoming available and has raised concerns about the relatively higher incidence of scaffold thrombosis (thorns of rose!). Due to the inherent material properties, polymeric bioresorbable scaffolds (BRS) have some limitations in mechanical aspects as compared to metallic stents. Biological aspect is also unique property of the BRS, which is however not fully elucidated. To reduce the rate of clinical events of BRS, procedural and device improvement are being evaluated. Deep understanding of pathophysiology of the clinical events would be a key to find a right course to follow. Intravascular imaging modalities such as OCT and IVUS would be the only way to precisely investigate mechanical and pathophysiological causes of the clinical events. Primary goals of the present thesis are as follows: 1) To develop novel methodologies for the specific assessment of acute and long-term performance of BRS; 2) To apply the dedicated intravascular imaging analysis in evaluating acute and long-term performance of BRS in a clinical setting; 3) To investigate mechanical and pathophysiological causes of the clinical events of BRS; 4) To give some in-depth insights into the possible solution of drawbacks of the current BRS.