title: Plaque composition in the left main stem mimics the distal but not the proximal tract of the left coronary artery: influence of clinical presentation, length of the left main trunk, lipid profile, and systemic levels of C-reactive protein.
abstract: OBJECTIVE
  We sought to investigate whether plaques located in the left main stem (LMS) differ in terms of necrotic core content from those sited in the proximal tract of the left coronary artery.
  
  
  BACKGROUND
  Plaque composition, favoring propensity to vulnerability, might be nonuniformly distributed along the vessel, which might explain the greater likelihood for plaque erosion or rupture to occur in the proximal but not in the distal tracts of the coronary artery or in LMS.
  
  
  METHODS
  A total of 72 patients were included prospectively; 48 (32 men; mean age 57 +/- 11 years; 25 with stable angina and 23 affected by acute coronary syndromes) underwent a satisfactory nonculprit vessel investigation through spectral analysis of intravascular ultrasound radiofrequency data (IVUS-Virtual Histology, Volcano Corp., Rancho Cordova, California). The region of interest was subsequently divided into LMS and LMS carina, followed by 6 consecutive nonoverlapping 6-mm segments in left anterior descending artery in 34 patients or in circumflex artery in 14 patients.
  
  
  RESULTS
  Necrotic core content (%): 1) was minimal in LMS (median [interquartile range]: 4.6 [2 to 7]), peaked in the first 6-mm coronary segment (11.8 [8 to 16]; p < 0.01), and then progressively decreased distally; 2) was overall greater in patients with acute coronary syndromes (11.4 [5.5 to 19.8]) than stable angina (7.3 [3.2 to 12.9]; p < 0.001); 3) was largely independent from plaque size; and 4) did not correlate to systemic levels of C-reactive protein or lipid profile.
  
  
  CONCLUSIONS
  Plaques located in the LMS carry minimal necrotic content. Thus, they mimic the distal but not the proximal tract of the left coronary artery, where plaque rupture or vessel occlusion occurs more frequently.
authors.affiliation: Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands.
authors.forename: Marco
authors.initials: M
authors.lastname: Valgimigli
authors.forename: Gastón A
authors.initials: GA
authors.lastname: Rodriguez-Granillo
authors.forename: Héctor M
authors.initials: HM
authors.lastname: Garcia-Garcia
authors.forename: Sophia
authors.initials: S
authors.lastname: Vaina
authors.forename: Peter
authors.initials: P
authors.lastname: De Jaegere
authors.forename: Pim
authors.initials: P
authors.lastname: De Feyter
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D003331:Coronary Vessels / Q000737:chemistry*; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D011446:Prospective Studies; D018084:Ultrasonography, Interventional
chemical_list: D008055:Lipids; D002097:C-Reactive Protein