Author + information
- Norvydas Zapustas1,
- Robertas Pranevicius2,
- Kasparas Briedis2,
- Azuolas Sirtautas1,
- Ramunas Unikas2 and
- Zivile Valuckiene2
Coronary plaque composition cannot be assessed accurately using gray-scale intravascular ultrasound (IVUS). Using virtual histology IVUS (VH-IVUS), a comparison of coronary plaque composition between acute coronary syndromes (ACS) and stable angina pectoris (SAP) was performed.
Pre-intervention IVUS of de novo culprit and target lesions was performed in 46 patients (20 with ACS and 26 with SAP). Using VH-IVUS, plaque was characterized as fibrotic, fibro-fatty, dense calcium, and necrotic core. VH-IVUS-derived thin-cap fibro-atheroma (VH-TCFA) was defined as necrotic core >10% of plaque area without overlying fibrous tissue in a plaque burden >40%. Lesions were classified into 3 groups: ruptured, VH-TCFA, and non-VH-TCFA plaque. Unstable lesions were defined as either VH-TCFA or ruptured plaque.
Compared with patients with SAP, those with ACS had significantly more unstable lesions (89% vs 62%, p <0.001). Planar VH-IVUS analysis at the minimum luminal site and at the largest necrotic core site and volumetric analysis over a 10-mm-long segment centered at the minimum luminal site showed that the percentage of necrotic core was significantly greater and that the percentage of fibro-fatty plaque was significantly smaller in patients with ACS. The percentages of fibrotic and fibro-fatty plaque areas and volumes were smaller, and the percentages of necrotic core areas and volumes were larger in VH-TCFAs compared with non-TCFAs. Ruptured plaques in VH-IVUS analyses showed intermediate findings between VH-TCFAs and non-VH-TCFAs.
Culprit lesions in patients with ACS were more unstable and had greater amounts of necrotic core and smaller amounts of fibro-fatty plaque compared with target lesions in patients with SAP.