Screening of ruptured plaques in patients with coronary artery disease by intravascular ultrasound
- J Gea,
- F Chirillob,
- J Schwedtmanna,
- G Görgea,
- M Haudea,
- D Baumgarta,
- V Shaha,
- C von Birgelena,
- S Sacka,
- H Boudoulasc,
- R Erbela
- aDepartment of Cardiology, University Essen, Hufelandstr 55, 45122 Essen, Germany, bDepartment of Cardiology, Regional Hospital Treviso, Italy, cDivision of Cardiology, Ohio State University, Ohio, USA
- Dr Ge.
- Accepted 15 December 1998
Abstract
AIM 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)% v67.9 (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.
