Optical coherence tomography characterization of degradation kinetics between second- and third-generation resorbable magnesium scaffold.

Abstract

This preclinical study aimed to establish optical coherence tomography (OCT)-derived parameters that could be used in the clinical setting for assessing strut degradation in the third-generation drug-eluting resorbable magnesium scaffold (DREAMS-3G), and characterize the comparative degradation profile against its precursor device (MagmarisTM scaffold). Twelve DREAMS-3G and 10 MagmarisTM scaffolds were implanted in juvenile pigs, and OCT images obtained at baseline and follow-up (6 or 12 months). Strut degradation was assessed by planimetric analysis and compared with OCT-derived indices to validate their diagnostic accuracy. A total of 3327 struts of DREAMS-3G and 2995 struts of the MagmarisTM scaffold were delineated by OCT. DREAMS-3G exhibited a significantly higher number of visible struts per analyzed frame at 6 months than the MagmarisTM scaffold, in the absence of significant differences at 12 months. Attenuation index (AtI) analysis indicated DREAMS-3G degradation was less advanced at 6 months but more advanced at 12 months compared to the MagmarisTM scaffold. These OCT-derived indices significantly correlated with the results of the planimetric analysis. The current preclinical study validated OCT indices that may serve as clinical surrogate markers for scaffold degradation. AtI analysis indicated that DREAMS-3G showed less degradation at 6 months but more advanced degradation at 12 months compared to the MagmarisTM scaffold, which corroborates the findings from planimetric analysis.