Screening of ruptured plaques in patients with coronary artery disease by intravascular ultrasound.
OBJECTIVE
To visualise the characteristics of ruptured plaques by intravascular ultrasound (IVUS) and to correlate plaque characteristics with clinical symptoms to establish a quantitative index of plaque vulnerability.


METHODS
144 consecutive patients with angina were examined using IVUS. Ruptured plaques, characterised by a plaque cavity and a tear on the thin fibrous cap, were identified in 31 patients (group A), of whom 23 (74%) presented with unstable angina. Plaque rupture was confirmed by injecting contrast medium filling the plaque cavity during IVUS examination. Of the patients without plaque rupture (group B, n = 108), only 19 (18%) had unstable angina.


RESULTS
No significant differences were found between groups A and B in relation to plaque and vessel area (p > 0.05). Mean (SD) per cent stenosis in group A was less than in group B, at 56.2 (16.5)% v 67.9 (13.4)%; p < 0.001. Area of the emptied plaque cavity in group A (4.1 (3.2) mm2) was larger than the echolucent zone in group B (1.32 (0.79) mm2) (p < 0.001). The plaque cavity to plaque ratio in group A (38.5 (17.1)%) was larger than the echolucent area to plaque ratio in group B (11.2 (8.9)%) (p < 0.001). The thickness of the fibrous cap in group A was less than in group B, at 0.47 (0.20) mm v 0.96 (0.94) mm; p < 0.001.


CONCLUSIONS
Plaques seem to be prone to rupture when the echolucent area is larger than 4.1 (3.2) mm2, when the echolucent area to plaque ratio is greater than 38.5 (17.1)%, and when the fibrous cap is thinner than 0.7 mm. IVUS can identify plaque rupture and vulnerable plaques. This may influence patient management and treatment.
Ge
J
J
Department of Cardiology, University Essen, Hufelandstr 55, 45122 Essen, Germany.
Chirillo
F
F
Schwedtmann
J
J
Görge
G
G
Haude
M
M
Baumgart
D
D
Shah
V
V
von Birgelen
C
C
Sack
S
S
Boudoulas
H
H
Erbel
R
R
D000328:Adult; D000368:Aged; D000789:Angina, Unstable / Q000000981:diagnostic imaging* / Q000209:etiology; D002118:Calcium / Q000032:analysis; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D012307:Risk Factors; D012422:Rupture, Spontaneous / Q000000981:diagnostic imaging; D018084:Ultrasonography, Interventional
D002118:Calcium