The possibility of delayed arterial healing 5 years after implantation of sirolimus-eluting stents: Serial observations by coronary angioscopy

• Published in: The American heart journal 2011-06, Vol.161 (6), p.1200-1206
• Main Authors: Yamamoto, Masanori, MD, Takano, Masamichi, MD, Murakami, Daisuke, MD, Inami, Toru, MD, Kobayashi, Nobuaki, MD, Inami, Sigenobu, MD, Okamatsu, Kentaro, MD, Ohba, Takayoshi, MD, Ibuki, Chikao, MD, Hata, Noritake, MD, Seino, Yoshihiko, MD, Jang, Ik-Kyung, MD, Mizuno, Kyoichi, MD
• Format: Article
• Language: English
• Subjects: Aged; Angina pectoris; Angioplasty, Balloon, Coronary; Angioscopy; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Cardiology. Vascular system; Cardiovascular; Coronary Angiography; Coronary Artery Disease - therapy; Coronary heart disease; Coronary Thrombosis - diagnosis; Coronary Thrombosis - epidemiology; Coronary Thrombosis - prevention & control; Coronary vessels; Coronary Vessels - pathology; Female; Heart; Heart attacks; Humans; Immunosuppressive Agents - administration & dosage; Male; Medical imaging; Medical sciences; Middle Aged; Neointima - diagnosis; Neointima - epidemiology; Pharmacology. Drug treatments; Radiography, Interventional; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Sirolimus - administration & dosage; Stents; Time Factors
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2011.03.006

Background Although very late stent thrombosis occurs several years after implantation of sirolimus-eluting stent (SES), the morphologic changes of the stent beyond 2 years have not yet been systematically studied in living patients. The late vascular response to SES was therefore evaluated by serial angioscopic studies at 2 and 5 years after stent implantation. Methods A total of 17 patients with 17 SES underwent a repeated angioscopy procedure at 2 and 5 years. Neointimal stent coverage (NSC) was classified as follows: grade 0, presence of uncovered struts; grade 1, visible struts through a thin neointima; or grade 2, complete neointimal coverage without visible struts. For each patient, the minimum and maximum NSC grade and the existence of in-stent thrombus were recorded. Results The minimum and maximum NSC grade did not increase between the 2 and 5 years (0.59 ± 0.51 vs 0.88 ± 0.70, P = .17, and 1.82 ± 0.39 vs 1.94 ± 0.24, P = .30, respectively). The prevalence of patients with uncovered struts did not significantly decrease from 2 to 5 years (41% vs 29%, P = .49). During the follow-up period, 3 of 6 thrombi disappeared, whereas new thrombus formation was found in 3 patients without any clinical symptoms. In-stent thrombus did not decrease (35% vs 35%, P > .99). Conclusions The current serial angioscopic study suggests that incomplete NSC and the prevalence of latent thrombus within the SES segments did not decrease from 2 to 5 years. The risk of stent thrombosis related to incomplete healing of SES may continue for an extended period.