title: Analysis of saphenous vein graft lesion composition using near-infrared spectroscopy and intravascular ultrasonography with virtual histology.
abstract: OBJECTIVE
  To examine the composition of saphenous vein graft (SVG) lesions using two novel modalities, near-infrared spectroscopy (NIRS) and intravascular ultrasonography with virtual histology (IVUS-VH).
  
  
  METHODS
  We performed NIRS and IVUS-VH imaging of 23 SVGs in 21 patients undergoing clinically-indicated angiography.
  
  
  RESULTS
  Mean patient and SVG age was 66±7 and 10±7 years, respectively. SVG lesion location was aorto-ostial in 8 (35%), body in 13 (57%) and distal anastomotic in 2 (9%). Compared to anastomotic lesions, body lesions had larger mean lumen area (6.4±1.8 mm2 vs. 4.2±6.4 mm2, P=0.02) but similar mean plaque burden (73±5% vs. 70±10%, P=0.66). A NIRS lipid core plaque was identified in 9 of 13 body lesions vs. 1 of 10 anastomotic lesions (69% vs. 10%, P=0.005). SVG body lesions had higher lipid core burden index (LCBI) compared to anastomotic lesions (184±76 vs. 49±54, P<0.001). By IVUS-VH, SVG lesions had high % necrotic core (28±10%) and % dense calcium (13±10%), without any significant difference between body and anastomotic sites. Older SVG age was associated with higher lesion and vessel LCBI (r=0.76 and r=0.64, respectively, P<0.001), but was not associated with IVUS-VH determined plaque composition. Higher HDL-cholesterol was associated with lower lesion LCBI (r=-0.43, P=0.04).
  
  
  CONCLUSIONS
  NIRS-measured lipid core plaque in SVGs increases with increasing SVG age and is infrequent in anastomotic lesions. No association was found between IVUS-VH plaque composition measurements and SVG lesion location or age.
authors.affiliation: VA North Texas Healthcare System and University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75216, USA.
authors.forename: Frances O
authors.initials: FO
authors.lastname: Wood
authors.forename: Neeraj
authors.initials: N
authors.lastname: Badhey
authors.forename: Bobby
authors.initials: B
authors.lastname: Garcia
authors.forename: Abdul-rahman
authors.initials: AR
authors.lastname: Abdel-karim
authors.forename: Brij
authors.initials: B
authors.lastname: Maini
authors.forename: Subhash
authors.initials: S
authors.lastname: Banerjee
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
mesh_terms: D000368:Aged; D000792:Angiography / Q000379:methods; D002118:Calcium / Q000378:metabolism; D008076:Cholesterol, HDL / Q000378:metabolism; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D012501:Saphenous Vein / Q000000981:diagnostic imaging* / Q000637:transplantation*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D008076:Cholesterol, HDL; D008055:Lipids; D002118:Calcium