Abstract 3788: A Virtual Histology Analysis of Plaque Shift after Drug-eluting Stent Implantation
Background. Virtual Histology (VH) intravascular ultrasound (IVUS) was developed to improve on the plaque classification of grey scale IVUS.
Methods. We used VH to evaluate plaque shift that occurs during stent implantation. 27 pts (30 lesions) were amenable to VH analysis before and after drug-eluting stent (DES) implantation. Standard IVUS measures were performed every 1mm within the lesion, stent, and stent edges. We divided the stented lesion and its reference into 7 segments including proximal and distal edge and compared the pre-intervention vs post-DES VH-IVUS (absolute amounts of fibrous, fibrofatty, dense calcium, and necrotic core). We excluded the stent strut and its artifact since these have not been validated for VH IVUS analysis.
Results. Pt age was 62±12yrs, 60% were males, and 17% were diabetic. Plaque areas increased at the proximal and distal stent edge after DES implantation: 7.60±3.65mm2 to 9.63±4.4μmm2 (p<0.001) at the proximal edge and 5.32±3.65mm2 to 7.86±3.79mm2 (p<0.0001) at the distal edge. As shown in the Table⇓, there was a consistent increase in necrotic core area at the proximal and distal edges and/or reference segments (p=0.423 and p=0.01, respectively), but no consistent change in other plaque components. Only fibro-fatty plaque area was decreased within the length of the stent.
Conclusion: Stent implantation is associated with redistribution (extrusion) of the necrotic core out of the stent proximally and distally. This may impact on acute complications - i.e., CK elevation - and long-term coronary events - i.e., edge restenosis and myocardial infarction.