title: The triple line pattern on carotid intima media thickness imaging and its relationship to cardiovascular risk factors in patients on lipid lowering therapy.
abstract: BACKGROUND
  Carotid intima media thickness (CIMT) infrequently identifies a triple line pattern (TLP) in the visualization of the internal elastic lamina. We examined the prevalence and predictors of the TLP among a consecutive series of subjects enrolled in a CIMT clinical trial, and also the effects of lipid lowering therapy.
  
  
  METHODS
  Baseline CIMT studies of subjects with known heart disease, or high risk for heart disease, were evaluated from a single site of the Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 6-HDL and LDL Treatment Strategies in Atherosclerosis trial (N=120). One sonographer obtained four views of the right and left far wall common CIMT, using a 13 MHz ultrasound probe. Images were blindly reviewed for the presence of the TLP. The TLP was defined as absent (0), possible (1), or definite (2). A composite score from all four views was calculated. A patient was defined as having the TLP if the composite score was ≥4. Univariate predictors of the TLP were explored. Follow-up ultrasounds at 14 months were also reviewed for presence of the TLP.
  
  
  RESULTS
  The prevalence of the TLP at baseline was 22.5%. Among cardiovascular risk variables, systolic blood pressure was significantly higher in subjects displaying the TLP (141.3±15.6 mmHg versus 133.1±18.4 mmHg; P=0.036). There were no differences among those with, and without, the TLP, with respect to other cardiovascular risk variables (age, sex, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, C-reactive protein, glucose, weight, waist girth, tobacco use, medications, quantitative CIMT), or image quality. During ongoing lipid lowering therapy, the prevalence of the TLP increased to 54.2% (P<0.001). However, it was unrelated to changes in lipid concentrations or cardiovascular risk variables.
  
  
  CONCLUSIONS
  The TLP in CIMT imaging is commonly identifiable using high-frequency ultrasound, and appears to be associated with higher systolic blood pressure. Its prevalence and incidence is unrelated to lipid parameters.
authors.affiliation: Division of Cardiology, Medstar Georgetown University Hospital, Bethesda, MD.
authors.forename: Tania A
authors.initials: TA
authors.lastname: Singh
authors.affiliation: Walter Reed National Military Medical Center, Bethesda, MD.
authors.forename: Todd C
authors.initials: TC
authors.lastname: Villines
authors.affiliation: Georgetown University School of Medicine, Washington, DC, USA.
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Taylor
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D002340:Carotid Artery Diseases / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000187:drug effects*; D059168:Carotid Intima-Media Thickness; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008055:Lipids
keywords: CIMT; HTN; atherosclerosis; risk factors