title: Intima-media thickness in the origin of right subclavian artery as an early marker of cardiovascular risk.
abstract: OBJECTIVE
  Common carotid artery intima-media thickness (IMT) is considered a factor of cardiovascular risk and an early marker of coronary artery disease. This study aimed to investigate the existence of a correlation between IMT in the carotid arteries and at the origin of the right subclavian artery, as well as to evaluate IMT in the subclavian artery as an earlier marker of cardiovascular risk.
  
  
  METHODS
  One hundred and six consecutive patients, 52 males and 54 females, average age 51 years, underwent color Doppler ultrasonography to evaluate carotid and right subclavian arteries. The relationship between carotid IMT and right subclavian IMT was assessed using the Pearson's correlation coefficient analysis and a 95% confidence interval. Reliability of right subclavian artery IMT measurement for the diagnosis of early thickening (considering a > 0.8 mm carotid thickness as reference) was described as to sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Cut-off values for the right subclavian IMT were indicated by the ROC curve, and p values < or = 0.05 were considered statistically significant.
  
  
  RESULTS
  Out of the 41 patients whose carotid arteries were IMT-free, 30 (73%) had right subclavian artery IMT values > 0.8 mm. The mean IMT value for the carotid artery was 0.87 mm (SD = 0.23) and for the subclavian artery, 1.17 mm (SD = 0.46), with a 0.31 correlation coefficient (95% CI: 0.12; 0.47). The ROC curve analysis indicated a cut-off value of 0.7 mm for the right subclavian artery IMT, using as reference a 0.8 mm cut-off value for the carotid artery (91% sensitivity, 27% specificity, 66% PPV, 65% NPV, and 66% accuracy).
  
  
  CONCLUSIONS
  Our study showed that carotid artery IMT correlates well with right subclavian artery IMT. With a 0.7 mm cut-off value, it is possible to detect IMT in the right subclavian artery earlier than in the carotid arteries. The IMT at the origin of the right subclavian artery can be considered an earlier marker for the assessment of cardiovascular risk.
authors.affiliation: Pontifícia Universidade Católica do Paraná e Angiolab, Curitiba, PR, Brazil. carlos.engelhorn@pucpr.br
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Engelhorn
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Engelhorn
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Cassou
authors.forename: Cassiana Casagrande
authors.initials: CC
authors.lastname: Zanoni
authors.forename: Carlos José
authors.initials: CJ
authors.lastname: Gosalan
authors.forename: Emerson
authors.initials: E
authors.lastname: Ribas
authors.forename: Adriana
authors.initials: A
authors.lastname: Pacholok
authors.forename: Marcela de Fátima
authors.initials: Mde F
authors.lastname: Koehler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology*; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013348:Subclavian Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography
chemical_list: D015415:Biomarkers