title: Histological validation of frequency domain optical coherence tomography for the evaluation of neointimal formation after a novel polymer-free sirolimus-eluting stent implantation.
abstract: Novel polymer-free drug-eluting stents have been developed to reduce polymer-related adverse events. However, neointimal coverage after polymer-free DES implantation is unclear and validation between optical coherence tomography (OCT) and histology is required. Sixteen polymer-free sirolimus-eluting stents were randomly implanted into coronary arteries of 8 normal swine. OCT and histological measurement were conducted at 3 or 6 months after stent placement. For quantitative measures, lumen area, stent area, neointimal area and neointimal thickness were validated in every single OCT and histology matched cross-section. Moreover, for qualitative analysis, OCT signal patterns of neointimal tissue were classified as homogeneous, layered and heterogeneous patterns based on optical intensity and backscatter pattern and peri-strut inflammation was also determined by histology. In total, 70 OCT and histology matched cross-sections were analyzed. At quantitative analysis, good correlations and agreements were found in the measurement of lumen area (ICC = 0.67, P<0.001), neointimal area (ICC = 0.89, P<0.001) and neointimal thickness (ICC = 0.94, P<0.001) except for stent area (ICC 0.19, P = 0.13) between OCT and histology. At qualitative analysis, lymphocyte infiltrations of peri-strut were more frequently seen in heterogeneous sections than in homogeneous sections (10/14 sections, 71.4% vs. 12/50 sections, 24%; P = 0.003). In conclusion, OCT has proper correlation and agreement with histology in assessment of neointimal formation and heterogeneous neointima assessed by OCT may also be associated with peri-strut inflammation detected in histology after polymer-free sirolimus-eluting stents implantation, supporting the use of OCT to evaluate neointimal coverage after polymer-free stent implantation in clinical practice.
authors.affiliation: Department of Cardiology, Beijing Tiantan Hospital, Capital Medical University Beijing, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: Department of Cardiology, Beijing Tiantan Hospital, Capital Medical University Beijing, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Hu
authors.affiliation: Department of Cardiology, Beijing Tiantan Hospital, Capital Medical University Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Cardiology, Beijing Tiantan Hospital, Capital Medical University Beijing, China.
authors.forename: Zhixu
authors.initials: Z
authors.lastname: Tan
authors.affiliation: Department of Pathology, National Center for Cardiovascular Disease, China and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Cardiology, Beijing Tiantan Hospital, Capital Medical University Beijing, China.
authors.forename: Dezhao
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Beijing Tiantan Hospital, Capital Medical University Beijing, China.
authors.forename: Buxing
authors.initials: B
authors.lastname: Chen
mesh_terms: D000818:Animals; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D003331:Coronary Vessels / Q000187:drug effects* / Q000473:pathology; D054855:Drug-Eluting Stents; D023421:Models, Animal; D058426:Neointima; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation*; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D015203:Reproducibility of Results; D020123:Sirolimus / Q000008:administration & dosage*; D013552:Swine; D013997:Time Factors; D041623:Tomography, Optical Coherence
chemical_list: D002317:Cardiovascular Agents; D020123:Sirolimus
keywords: Polymer-free; histology; neointima; optical coherence tomography