title: Renal artery plaque composition is associated with changes in renal frame count following renal artery stenting.
abstract: BACKGROUND
  Benefit of percutaneous revascularization for atherosclerotic renal artery stenosis (RAS) may be attenuated by distal embolization of atheroemboli. The purpose of this study was to characterize RAS plaque composition with intravascular ultrasound virtual histology (IVUS-VH) and to explore the relationship between plaque components and renal frame count (RFC) after renal revascularization.
  
  
  METHODS
  Seventeen patients (75 ± 7.5 years; 18 lesions) undergoing RAS revascularization were included. Before stenting, automated IVUS-VH pullback (0.5 mm/sec) with analysis of the minimal luminal diameter (MLD) frame and entire atherosclerotic segment was performed. RFC was also determined before and after stenting.
  
  
  RESULTS
  The VH component analysis of the segment demonstrated predominantly fibrous tissue (56.3 ± 11.4%), followed by necrotic core (21.8 ± 8.6%), dense calcification (13.2 ± 6.6%) and fibrofatty tissue (8.7 ± 4.0%). Analysis of the MLD frame also demonstrated mostly fibrous tissue (62.1 ± 11.1%), with smaller amounts of necrotic core (15.6 ± 7.3%), fibrofatty (13.9 ± 9.6%), and dense calcification (8.4 ± 6.0%). A trend toward more fibrous tissue (p = 0.074), less necrotic core (p = 0.095) and less dense calcification (p = 0.075) at the MLD compared to the segment was observed. Analysis of the entire atherosclerotic segment revealed a positive correlation between % necrotic core and change in RFC (r = 0.582; p = 0.029), with increasing necrotic core associated with an increase in RFC after revascularization.
  
  
  CONCLUSIONS
  Both the MLD frame and segmental analysis of atherosclerotic RAS lesions demonstrate predominantly fibrous tissue with smaller amounts of necrotic core, fibrofatty tissue, and dense calcification. Increased necrotic core correlates with a lack of improvement in RFC after stenting.
authors.affiliation: University of California, San Diego, Division of Cardiology, UCSD Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8784, USA.
authors.forename: Anand
authors.initials: A
authors.lastname: Prasad
authors.forename: Manjusha
authors.initials: M
authors.lastname: Ilapakurti
authors.forename: Patrick
authors.initials: P
authors.lastname: Hu
authors.forename: Nayab
authors.initials: N
authors.lastname: Zafar
authors.forename: Vachaspathi
authors.initials: V
authors.lastname: Palakodeti
authors.forename: Sotirios
authors.initials: S
authors.lastname: Tsimikas
authors.forename: Ehtisham
authors.initials: E
authors.lastname: Mahmud
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology*; D008297:Male; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000473:pathology*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000628:therapy*; D015607:Stents; D018084:Ultrasonography, Interventional