title: Definitions and methodology for the grayscale and radiofrequency intravascular ultrasound and coronary angiographic analyses.
abstract: OBJECTIVE
  In a prospective study of the natural history of coronary atherosclerosis using angiography and grayscale and radiofrequency intravascular ultrasound (IVUS)-virtual histology (VH), larger plaque burden, smaller luminal area, and plaque composition thin-cap fibroatheroma emerged as independent predictors of future adverse cardiovascular events.
  
  
  BACKGROUND
  The methodology for IVUS-VH classification for an in vivo natural history study and the prospective image mapping by angiography and grayscale and IVUS-VH have not been established.
  
  
  METHODS
  All culprit and nonculprit lesions (defined as ≥ 30% angiographic visual diameter stenoses) were analyzed. Three epicardial vessels as well as all ≥ 1.5-mm-diameter side branches were divided into 29 CASS (Coronary Artery Surgery Study) segments. Each CASS segment was then subdivided into 1.5-mm-long subsegments, and dimensions were analyzed. All grayscale and IVUS-VH slices from the proximal 6 to 8 cm of the 3 coronary arteries were analyzed, with lesions defined as having more than 3 consecutive slices with ≥ 40% plaque burden categorized as: 1) VH thin-cap fibroatheroma; 2) thick-cap fibroatheroma; 3) pathological intimal thickening; 4) fibrotic plaque; or 5) fibrocalcific plaque. The locations of angiographic and grayscale and IVUS-VH lesions were recorded in relation to the corresponding coronary artery ostium and nearby side branches.
  
  
  RESULTS
  The 3-year cumulative rate of major adverse cardiovascular events was 20.4%. Events were adjudicated to culprit lesions in 12.9% of patients and to nonculprit lesions in 11.6%. On multivariate analysis, nonculprit lesions associated with recurrent events were characterized by a plaque burden ≥ 70% (hazard ratio: 5.03; 95% confidence interval: 2.51 to 10.11; p < 0.0001), a minimal luminal area ≤ 4.0 mm(2) (hazard ratio: 3.21; 95% confidence interval: 1.61 to 6.42; p = 0.001), and IVUS-VH phenotype of a thin-cap fibroatheroma (hazard ratio: 3.35; 95% confidence interval: 1.77 to 6.36; p < 0.001).
  
  
  CONCLUSIONS
  Three-vessel multimodality coronary artery imaging was feasible and allowed the identification of lesion-level predictors for future events in this natural history study.
authors.affiliation: Columbia University Medical Center and the Cardiovascular Research Foundation, New York, New York 10022, USA. amaehara@crf.org
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
authors.forename: Ecaterina
authors.initials: E
authors.lastname: Cristea
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Lansky
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Dressler
authors.forename: Sinan
authors.initials: S
authors.lastname: Biro
authors.forename: Barry
authors.initials: B
authors.lastname: Templin
authors.forename: Renu
authors.initials: R
authors.lastname: Virmani
authors.forename: Bernard
authors.initials: B
authors.lastname: de Bruyne
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000401:mortality; D017023:Coronary Angiography / Q000592:standards; D003324:Coronary Artery Disease / Q000145:classification / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D023921:Coronary Stenosis / Q000145:classification / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D018450:Disease Progression; D005060:Europe / Q000453:epidemiology; D005260:Female; D005355:Fibrosis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000592:standards; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058426:Neointima / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D009626:Terminology as Topic; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000592:standards; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000000981:diagnostic imaging