Original Studies Angioscopy Study From a Large Patient Population Comparing Sirolimus-Eluting Stent With Biodegradable Versus Durable Polymer Shao-Liang Chen, 1,2 * MD, Tian Xu, 2 MBBS, Jun-Jie Zhang, 1 MD, Fei Ye, 1 MD, Zuo-Ying Hu, 2 MD, Nai-Liang Tian, 2 MD, Yao-Jun Zhang, 1 MD, Junichi Kotani, 3 MD, and Jun-Xia Zhang, 2 MD Aims: This study aimed to compare the neointimal coverage (NIC), subclinical thrombus, color of plaque underneath the stent at 9-month after implantation of sirolimus-eluting stent (SES) either with durable or with biodegradable polymer (BDPM). Methods: A total of 175 patients were assigned as Cypher (n 5 81, 97 stents with durable polymer) and Excel (n 5 94, 112 stents with BDPM) stent at 9-month after indexed procedure. NIC was classi- fied from grade 0–3. Color of plaque was divided into white, light-yellow, yellow, and dark yellow. Thrombus was diagnosed as white or red material with cotton-like or ragged appearance. Incomplete NIC (grade 0/1) circled by a blush was termed by ‘‘inflaming.’’ Results: There were significant differences in unstable angina (90.5 vs. 52.4%, P 5 0.015), previous myocardial infarction (33.3 vs. 4.0%, P 5 0.045) and left ventricular eject fraction (55.2 6 7.8 vs. 62.6 6 6.3%, P 5 0.021) between the Excel and Cypher groups. The mini- mal- and maximal-NIC grades in the Cypher group were 0.67 6 0.58 and 2.29 6 0.46, respectively, when compared with 1.45 6 0.67 (P < 0.001) and 2.64 6 0.49 (P 5 0.023) in the Excel group. The percentage of yellow plaque, thrombus, ‘‘inflaming’’ and NIC grade of 0 in the Excel and Cypher groups, respectively, were as follows: 8.0 vs. 26.8% (P 5 0.031), 9.8 vs. 32.9% (P 5 0.024), 8.0 vs. 38.1% (P 5 0.017), and 38.1 vs. 0% (P < 0.001). Of the stents with ‘‘inflaming,’’ 63.6% had thrombus when compared with 20.1% of the non- erosion stents (P < 0.001). Overlapping segments had the lowest NIC grades and more ‘‘inflaming’’ demonstrating a significant difference between Cypher vs. Excel stents. NIC grade was positively correlated with thrombus. Conclusions: SES with BDPM has improved NIC resulting in less yellow plaque, thrombus, and ‘‘inflaming.’’ Overlapping segments had the lowest NIC grade and more ‘‘inflaming.’’ V C 2011 Wiley Periodicals, Inc. Key words: biodegradable polymer; angioscopy; neointimal coverage; thrombus INTRODUCTION Implantation of sirolimus-eluting (SES) when com- pared with bare-metal stent is associated with signifi- cant reduction of restenosis by inhibiting neointimal hyperplasia, resulting in decreased target lesion/vessel revascularization [1–3]. Insufficient neointimal cover- age (NIC), as seen after brachytherapy [4,5], may be prolonged up to 1-year after SES implantation [6,7] and may contribute to the development of stent throm- bosis. Angioscopy, allowing for detailed visualization of lumen/stent surface, has demonstrated suppressed NIC after use of first-generation DES [8,9]. Pathological studies have reported that the presence of permanent polymer plays a central role in delayed 1 Division of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China 2 Division of Cardiology, Nanjing Heart Center, Nanjing, China 3 National Cerebral and Cardiovascular Center, Osaka, Japan Conflict of interest: Nothing to report. *Correspondence to: Dr. Shao-Liang Chen, MD, Cardiological Department, Nanjing First Hospital, Nanjing Medical University, 210006 Nanjing, China. E-mail: chmengx@126.com Received 14 May 2011; Revision accepted 2 July 2011 DOI 10.1002/ccd.23306 Published online in Wiley Online Library (wiley onlinelibrary.com) V C 2011 Wiley Periodicals, Inc. Catheterization and Cardiovascular Interventions 00:000–000 (2011)