Relation between plaque type and dissections at the edges after stent implantation: an optical coherence tomography study.

BACKGROUND Stent implantation can create vessel damage such as edge dissections. The objectives were i) to evaluate the frequency of edge dissections after stenting visible by intracoronary optical coherence tomography (OCT) in comparison with angiography. ii) to assess with OCT the plaque type left at the stent edges after implantation, and iii) to study whether there is an association between plaque type and dissections at stent edges. METHODS Seventy-three consecutive patients (80 vessels) with OCT post-stent implantation were included in the study. By OCT, plaque type at stent edges and presence of edge dissection were assessed. Angiograms were analyzed by two independent observers to assess the presence of edge dissections. RESULTS Distal and proximal edges were visible by OCT in 72/80 and 45/80 vessels respectively. OCT and angiography agreed in the detection of 7 dissections at distal edge (κ=0.32) and 1 dissection at proximal edge (κ=0.22). Plaque type at distal edge was: fibrotic 55.6%, fibrocalcific 22.2%, fibroatheroma 15.3% and thin-cap fibroatheroma (TCFA) 6.9%. At proximal edge plaque type was: fibrotic 31.1%, fibrocalcific 33.3%, fibroatheroma 28.9% and TCFA 6.7%. In the distal edge, presence of edge dissection was significantly more frequent when the plaque type at the edge was fibrocalcific (43.8%) or lipid rich (37.5%) than when the plaque was fibrous (10%) p=0.009. CONCLUSIONS OCT showed higher sensitivity compared to angiography for the identification of edge dissections. A high proportion of patients showed lipid-rich plaques at stent edges. Plaque type at the stent edges has impact on the presence of edge dissections.