Acute and long-term relocation of minimal lumen area after bioresorbable scaffold or metallic stent implantation.

The aim of this study was to investigate relocation of minimal lumen area (MLA) after implantation of a bioresorbable scaffold (BRS). In the ABSORB II randomised trial (BRS vs everolimus-eluting stent [EES]), lesions were investigated by serial intravascular ultrasound pre procedure, post procedure, and at three years. MLA relocation was defined as an axial MLA shift of more than 2.4 mm. MLA relocation from post procedure to three years was observed in 163/237 (68.8%) and 75/129 (58.1%) of lesions treated by BRS and EES, respectively (p=0.041). When matching preprocedural MLA site with the same topographical sites post procedure and at three years, BRS showed significant late lumen enlargement and expansive remodelling compensating for significant plaque increase, whereas EES showed significant late lumen narrowing with significant plaque growth not compensated for by expansive remodelling from post procedure to three years. In the multivariate analysis, female gender, previous PCI, BRS implantation, total device length, and maximal pressure (either at device implantation or post-dilatation) were independently associated with MLA relocation from post procedure to three years. MLA relocation from post procedure to three years was more frequent in BRS than EES. Late lumen enlargement and expansive vessel remodelling at the preprocedural MLA site was observed in BRS, but not in EES.