Coronary plaque dimensions and composition by intravascular ultrasound radio frequency lesion segment analysis in stable and unstable angina patients

Aims: We hypothesized that the plaque composition and plaque type classification differs between acute coronary syndrome (ACS) and stable angina (SA) patients. Methods and results: We analyzed culprit lesion (CL) and nonculprit lesion (NCL) of ACS patients compared with target lesion (TL) and nontarget lesion (NTL) of SA patients by intravascular ultrasound radio frequency analysis in 874 lesion segments of 424 patients (ACS: 193 patients/SA: 231patients). Comparing all lesion segments in ACS and SA patients did not show significant differences in absolute or relative plaque composition. However, necrotic core area was larger in CL versus TL (0.9 ± 0.7 vs. 0.7± 0.5mm2, P = 0.005) and all plaque components were significantly higher in CL compared with NCL and TL compared with NTL, respectively. A higher amount of thin cap fibroatheroma lesions (15.2 vs. 5.1%, P <0.0001) was detected in ACS compared with SA patients. Fibrocalcific lesions were lower in ACS patients (3 vs. 10.5%, P < 0.0001). Conclusion: The differentiation in CL/NCL of ACS and TL/NTL of SA patients revealed significant differences in plaque composition and plaque types when examined by intravascular ultrasound radiofrequency analysis. However, considerable overlap between plaque characteristics existsfor ACS and SA patients.