Angiographically 'silent' plaque in the left main coronary artery detected by intravascular ultrasound.
BACKGROUND
Left main coronary artery (LMCA) atherosclerosis is a high-risk disease but its occurrence is often underestimated by coronary angiography. Intravascular ultrasound (IVUS) has been shown to be more accurate and sensitive than coronary angiography in identifying coronary atherosclerotic lesions.


METHODS
Ninety-two patients (55 men and 37 women, aged 55.4 +/- 10.4 years) found to have angiographically normal coronary arteries or ambiguous lesions of the LMCA were examined by IVUS after diagnostic cardiac catheterization. The cross-sectional areas of the vessel, lumen, and atherosclerotic plaque (if any) of the LMCA were determined and the percentage area and diameter of stenosis were calculated.


RESULTS
Atherosclerotic plaques in the LMCA were detected in 31 of the 92 patients (34%); 83% of the plaques were eccentric, and 17% contained calcium deposits. In patients with plaques detected by IVUS, the vessel area was 23.3 +/- 6.1 mm2. The plaque area was 6.3 +/- 3.3 mm2 (1.8-16.7 mm2). The area of stenosis was 31.6 +/- 12.1% (12-57.2%). The diameter of stenosis was 19.3 +/- 7.2% (8.7-34.6%). The area of stenosis was over 50% in four patients. The vessel area (23.3 +/- 6.1 mm2) in patients with plaques was larger than that in those without plaques (19.0 +/- 6.5 mm2, P < 0.01).


CONCLUSIONS
Coronary angiography considerably underestimates the occurrence of atherosclerotic stenoses in the LMCA because of coronary remodelling and methodological limitations. The greater sensitivity and accuracy of IVUS in detecting LMCA lesions, at both early and advanced stages, is of great clinical importance in patient management.
Ge
J
J
Department of Cardiology, University of Essen, Germany.
Liu
F
F
Görge
G
G
Haude
M
M
Baumgart
D
D
Erbel
R
R
D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018084:Ultrasonography, Interventional