Quality difference of neointima following the implantation of bioresorbable scaffold and metallic stent in patients with ST elevation myocardial infarction: quantitative assessments by light intensity, light attenuation, and backscatter on optical coherence tomography in TROFI II trial.

Aims: We aimed to assess possible differences in neointimal quality after everolimus-eluting bioresorbable scaffold (BVS) implantation in comparison with cobalt-chromium everolimus-eluting scaffold (CoCr-EES) implantation by optical frequency domain imaging (OFDI). Methods and results: This study is a post hoc analysis of the TROFI II trial assessing neointimal quality six months after the implantation of BVS (N=82) and CoCr-EES (N=87) in STEMI patients. Neointimal light property analysis by OFDI fully automatically computed light attenuation, backscatter and light intensity for superficial and deep neointima. High light attenuation/backscatter and high light intensity are reportedly associated with lipidic change and tissue maturation, respectively. Superficial and deep neointima in BVS presented lower light attenuation than CoCr-EES (superficial: 0.77 +/- 0.15 vs. 1.271 +/- 0.55 mm(-1), p<0.001; deep: 0.88 +/- 0.20 vs. 1.17 +/- 0.27 mm(-1), p<0.001). Superficial neointima in BVS showed comparable backscatter to that of CoCr-EES (4.81 +/- 0.52 vs. 4.94 +/- 0.61, p=0.141), while deep neointima in BVS showed lower backscatter than that of CoCr-EES (4.60 +/- 0.62 vs. 4.97 +/- 0.62, p<0.001). Light intensity of superficial neointima was comparable between both aims (139 +/- 13 vs. 144 +/- 30, p=0.236), whereas light intensity of deep neointima in BVS was lower than CoCr-EES (129 +/- 14 vs. 138 +/- 21, p<0.001). Conclusions: The present OFDI comparison suggested that tissue maturation was comparable but lipidic change of neointima was less prominent after BVS than after CoCr-EES implantation.