title: Assessing intermediate coronary lesions: angiographic prediction of lesion severity on intravascular ultrasound.
abstract: BACKGROUND
  Intravascular ultrasound (IVUS) can detect atherosclerotic compromise in coronary segments where conventional angiography cannot. However, IVUS is more invasive, expensive and laborious than angiography. We compared the detection of stenosis by IVUS and angiography and identified angiographic predictors of severe luminal stenosis on IVUS in patients with angiographically-intermediate coronary lesions.
  
  
  METHODS
  Fifty-six patients with myocardial ischemia and intermediate stenosis by quantitative coronary angiography (QCA) underwent IVUS assessment of the culprit artery. The results from IVUS and QCA were compared using the two-tailed unpaired t-test. Multiple regression analysis was performed to identify QCA parameters that could predict the presence of severe stenosis on IVUS, defined as a minimum luminal area (MLA) < or = 4 mm2.
  
  
  RESULTS
  A total of 63 stenotic coronary lesions were classified as intermediate by QCA; 68% of these were found to be severe on IVUS. There was a weak correlation between IVUS and QCA with respect to percentage of stenosis, minimum luminal diameter, reference segment diameter and length of atherosclerotic compromise. In contrast, there was a significant difference in the assessment of reference segment luminal diameter, which was 2.83 +/- 0.56 mm by angiography versus 3.45 +/- 0.69 mm by IVUS (p < 0.0001). The only angiographic predictor of the presence of severe coronary stenosis on IVUS was a distal reference segment diameter < or = 2.42 mm.
  
  
  CONCLUSIONS
  In patients with angiographically-intermediate lesions, the frequency of severe stenosis detected by IVUS was high, indicating that angiography underestimated the severity of stenosis. Distal reference segment diameter was the only predictor of a small MLA and could be used to stratify these lesions into groups with higher and lower risk of severe stenosis.
authors: Rede D'or Hospitais, Rio de Janeiro, Brazil. mfernandes@heart.thi.tmc.edu
authors: Marlos R
authors: MR
authors: Fernandes
authors: Guilherme V
authors: GV
authors: Silva
authors: Adriano
authors: A
authors: Caixeta
authors: Miguel
authors: M
authors: Rati
authors: Nelson A
authors: NA
authors: de Sousa e Silva
authors: Emerson C
authors: EC
authors: Perin
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000592:standards; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000592:standards