Abstract 1986: Incidence of Ruptured Plaque and Thin-Cap Fibroatheroma Using a 3-Vessel Virtual Histology Intravascular Ultrasound in 212 Patients
Using a 3-vessel Virtual Histology (VH) intravascular ultrasound (IVUS), we evaluated incidence of VH-IVUS-derived thin-cap fibroatheroma (VH-TCFA) and ruptured plaque between acute coronary syndrome (ACS) and stable angina pectoris (SAP). Pre-intervention VH-IVUS study was performed in 212 patients (105 ACS and 107 SAP). Plaque was characterized as fibrotic, fibrofatty, dense calcium, and necrotic core. 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. Culprit lesions in ACS contained 32 ruptured plaques (31%), 64 VH-TCFAs (61%), and 9 non-VH-TCFA (9%); conversely, 11 (10%), 55 (51%) and 41 (38%) in target lesions in SAP, p<0.001 ACS vs. SAP. There were ruptured plaque in 55 lesions in ACS and 21 lesions in SAP. VH-TCFAs were observed in 262 lesions in ACS and 177 lesions in SAP. Number of ruptured plaque per patient was 0.5±0.8 and 0.2±0.5 (p<0.001). Number of VH-TCFA per patient was 2.5±1.5 and 1.7±1.1 (p<0.001). Frequency distribution of VH-TCFA between ACS and SAP is shown in Figure⇓. Multiple (≥ 2) ruptured plaques were found in 12 (11%) ACS and 1 (1%) SAP (p<0.001). Seventy-six (72%) ACS and 58 (54%) SAP had multiple VH-TCFA (p=0.009). The only independent predictor for multiple ruptured plaque and multiple VH-TCFAs was ACS (p=0.013, OR=13.672, 95% CI=1.745 to 107.120 and p=0.011, OR=2.181, 95% CI=1.197 to 3.972).
Conclusion: Three-vessel VH-IVUS imaging showed that average numbers of VH-FCTA as well as ruptured plaque were greater in ACS than SAP. Both multiple ruptured plaques and VH-TCFAs were more common in ACS.