Coronary Arterial Remodeling and Out-Stent Plaque Change After Drug-Eluting Stent Implantation

BACKGROUND: Out-stent plaque characteristics and eosinophilic inflammatory response, which correlates with positive remodeling after first-generation drug-eluting stent implantation, may be associated with late restenosis and very late stent thrombosis. The differences of out-stent plaque characteristics were compared between paclitaxel-eluting stents (PES) and zotarolimus-eluting stents (ZES), using integrated backscatter-intravascular ultrasound (IB-IVUS). METHODS AND RESULTS: Of 78 patients enrolled, 25 receiving PES and 25 receiving ZES had adequate IVUS assessment. Volumetric IVUS analysis was performed after stenting and at 8-month follow-up. Out-stent plaque change in the stented segment was compared on IB-IVUS. The relationship between systemic inflammatory response and out-stent plaque change was evaluated. In PES, vessel volume significantly increased (365-389 mm(3), P<0.0001), whereas it did not change in ZES (315-314 mm(3), P=0.81). In culprit lesions at baseline in PES, fibrous plaque tended to increase (3.1-3.6mm(2), P=0.051) and lipid plaque significantly increased (4.3-5.1mm(2), P=0.02), whereas in ZES the fibrous plaque significantly increased (2.9-4.0mm(2), P<0.0001) but lipid plaque significantly decreased (5.1-3.6mm(2), P<0.0001). Systemic eosinophil increase was significantly correlated with positive remodeling and out-stent lipid plaque increase. CONCLUSIONS: Chronic out-stent plaque change in ZES consisted of less positive remodeling and more favorable effects on out-stent plaque characteristics than PES. Systemic eosinophil change might be a marker of out-stent lipid plaque change.