Comparison of incidence and time course of neoatherosclerosis between bare metal stents and drug-eluting stents using optical coherence tomography.

Recent studies have reported the development of neoatherosclerosis inside stents and subsequent acute coronary syndrome secondary to disruption of neointimal hyperplasia. The aim of the study was to compare the characteristics of neointimal hyperplasia and its time course between bare metal stents (BMSs) and drug-eluting stents (DESs) using optical coherence tomography. A total of 138 stents were divided into 3 groups according to the follow-up period: early phase, <9 months (25 BMSs and 27 DESs); intermediate phase, ≥9 and <48 months (18 BMSs and 43 DESs); and delayed phase, ≥48 months (13 BMSs and 12 DESs). Optical coherence tomographic analysis included the presence of lipid-laden intima, percentage of lipid-rich plaque, and signal attenuation. The optical coherence tomographic findings were compared between the BMSs and DESs in each period, and the difference between the periods was also determined. In the early phase, a greater incidence of lipid-laden plaque (37% vs 8%, p = 0.02) and a greater percentage of lipid-rich plaque (12.9 ± 25.1% vs 1.2 ± 4.3%, p = 0.01) were found in the DESs than in the BMSs. In the intermediate phase, the DES group continuously showed a significantly greater incidence of lipid-laden plaque (63% vs 28%, p = 0.03) and greater percentage of lipid-rich plaque (24.8 ± 28.1% vs 4.1 ± 7.3%, p <0.01). In addition, signal attenuation was greater in the DES group, suggesting early changes in neointimal hyperplasia properties. In the delayed phase, lipid-laden plaque was the predominant type in both groups. In conclusion, lipid-rich neoatherosclerosis develops inside stents earlier in DESs than in BMSs. After 48 months, most restenotic stents will have developed lipid-laden neointima in both groups.
(Copyright © 2012. Published by Elsevier Inc.)