title: Predictors of stent strut malapposition in calcified vessels using frequency-domain optical coherence tomography.
abstract: OBJECTIVE
  Malapposition of stent struts to the arterial wall and suboptimal stent expansion have been linked with poor outcomes following percutaneous coronary intervention (PCI). The purpose of this study was to use optical coherence tomography (OCT) to investigate stent strut malapposition in relation to calcium distribution.
  
  
  RESULTS
  Twenty-three PCI patients underwent OCT before and after stent deployment. Patient and procedural details and lesion characteristics - including the extent and depth of calcification - were measured, and the number of malapposed struts following final postdilatation was quantified. Patient and lesion characteristics associated with malapposition were assessed using univariate and multivariate analyses. The mean lesion length was 25.2 ± 10.8 mm, with a minimal lumen area (MLA) of 2.2 ± 1.2 mm². Eight percent of all stent struts were malapposed, most commonly in the proximal part of the stent. By univariate analysis, the percentage of malapposed struts was found to correlate with the circumferential extent of calcification (P=.04); however, no correlation was seen with the depth of calcification. Using multivariate analysis, the circumferential extent of vessel wall calcification was the only plaque feature found to correlate with the percentage of malapposed struts (P=.01).
  
  
  CONCLUSIONS
  Using OCT to assess vessel wall characteristics, the circumferential extent of superficial calcification seen, and not the depth, correlated well with the percentage of malapposed struts following PCI.
authors.affiliation: NHLI Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, United Kingdom. c.dimario@rbht.nhs.uk.
authors.forename: Alistair C
authors.initials: AC
authors.lastname: Lindsay
authors.forename: Manuel
authors.initials: M
authors.lastname: Paulo
authors.forename: Kilickesmez
authors.initials: K
authors.lastname: Kadriye
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Tejeiro
authors.forename: Eduardo
authors.initials: E
authors.lastname: Alegría-Barrero
authors.forename: Pak Hei
authors.initials: PH
authors.lastname: Chan
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foin
authors.forename: Dimitris
authors.initials: D
authors.lastname: Syrseloudis
authors.forename: Carlo
authors.initials: C
authors.lastname: Di Mario
mesh_terms: D000368:Aged; D002114:Calcinosis / Q000175:diagnosis* / Q000453:epidemiology* / Q000473:pathology; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000473:pathology / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology*; D004868:Equipment Failure; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome