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

Aims: 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 (Magmaris^TM scaffold). Methods and Results: Twelve DREAMS-3G and 10 Magmaris^TM 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 Magmaris^TM scaffold were delineated by OCT. DREAMS-3G exhibited a significantly higher number of visible struts per analyzed frame at 6 months than the Magmaris^TM 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 Magmaris^TM scaffold. These OCT-derived indices significantly correlated with the results of the planimetric analysis. Conclusion: 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 Magmaris^TM scaffold, which corroborates the findings from planimetric analysis.