Objective We analyzed local vessel responses including neointimal hyperplasia(NIH) and plaque behind the struts(PBS) in drug-eluting stents(DES). Method We used POET trial data which is a prospective, multicenter, randomized trial to evaluate the efficacy of adjuvant balloons in procedure using DES randomly allocated(SES vs.PES). Serial(baseline and 8month follow-up) IVUS analysis was performed and we selected cases with 28mm long stents, which length is identically available with both stents, for subsegment analysis(7subsegments/4mm long for each). Result Total 44 lesions were valid for analysis and baseline characteristics were not different between groups. At follow up, significantly larger NIH and PBS increase were seen in PES compared with SES(1.09±0.84 vs. 0.34±0.46 for NIH p=0.019, 1.92±1.57 vs. -0.16±1.46 for PBS p=0.002). Subsegmental analysis showed positive correlation between NIH and PBS in PES(r=0.558, p<0.001), contrary to no correlation in SES(r=-0.181, p=ns). Unlike the data with bare metal stents, any relation between plaque burden and neointimal growth was not observed(r=-0.254, p=ns for SES, r=-0.263, p=ns for PES). Conclusion We found somewhat inert responses around SES, which is different from tissue growth around PES. The clinical impact of different perivascular responses between stents needs to be further investigated.
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