title: Impact of stent over-expansion at distal edge: insights from a 12-month follow-up study.
abstract: OBJECTIVE
  Although the use of drug-eluting stents has significantly reduced the incidence of restenosis and target lesion revascularization, in-stent and in-segment restenosis remain clinically challenging problems, the underlying mechanisms of which remain unknown. This study aimed to explore the outcomes of different stenting strategies in target vessels with different proximal and distal reference diameters (∆D ≥ 0.25 mm).
  
  
  METHODS
  In this prospective clinical study, 167 patients undergoing percutaneous coronary intervention with ∆D ≥ 0.25 mm according to QCA results were randomized into 2 groups. Group A (n = 85) was treated by a single stent with high-pressure balloon inflation. Group B (n = 82) was treated by a single stent, with high- and low-pressure balloon inflation at the proximal and distal segment, respectively. The target vessel size and late lumen loss were determined by angiographic analysis.
  
  
  RESULTS
  Compared with normal expansion, overexpansion increased the early minimum lumen diameter (A: 2.40 ± 0.18 mm vs. 2.89 ± 0.21 mm; B: 2.45 ± 0.14 mm vs. 2.49 ± 0.24 mm, p < 0.001), but also increased the percentage of late lumen loss (A: 18.22 ± 0.56%; B: 5.63 ± 0.41%, p < 0.001). Although the total restenosis ratio was similar in 2 groups, the incidence of late lumen loss of group A was higher than that of group B.
  
  
  CONCLUSIONS
  Stent overexpansion increased the early minimum lumen diameter, but also increased the occurrence of late lumen loss at the distal edge of the stent.
authors.affiliation: Department of Cardiology, the First Affiliated Hospital of Xiamen University, Siming District, Xiamen City, Fujian, China. liweihua@medmail.com.cn.
authors.forename: K-M
authors.initials: KM
authors.lastname: Lin
authors.forename: D-H
authors.initials: DH
authors.lastname: He
authors.forename: W-H
authors.initials: WH
authors.lastname: Li
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D017023:Coronary Angiography / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D054855:Drug-Eluting Stents / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome