Long-Term Follow-up of Neointimal Coverage of Sirolimus-Eluting Stents

Abstract

ecent clinical trials have proved that drug-eluting stents (DES) inhibit neointimal proliferation and reduce the risk of in-stent restenosis. 1,2 However, there have been major concerns regarding the potential development of late stent thrombosis related to delayed neointimal formation over the struts of the DES and the discontinuation of dual antiplatelet therapy. 3 Although the incidence of DES thrombosis is reported to be less than 1%, 4-8 the incidence of death or myocardial infarction associated with this thrombosis is greater than 60%, 9 and related mortality rates range from 20% to 45%. 6,10 In 2008, the AHA/ACC/SCAI recommended that dual antiplatelet drug therapy should continue for at least 12 months after DES implantation if patients are not at high risk of bleeding, 11 longer than had previously been suggested. In order to establish guidelines for the safe cessation of antiplatelet therapy after DES implantation, a large randomized clinical trial should be performed. Furthermore, it seems important to know whether adequate neointimal coverage of DES has been achieved before stopping dual antiplatelet therapy, especially the thienopyridines. With this clinical perspective, several intravascular ultrasound (IVUS) studies have sought to evaluate the neointimal coverage of sirolimuseluting stent (SES), but they have revealed that IVUS is unable to detect the neointimal layers covering the struts of most DES, even at long-term follow-up, because of its relatively low spatial resolution. 12 Editorial p 2210Intravascular optical coherence tomography (OCT) is a newly developed intravascular imaging modality with a maximal spatial resolution of 10 μm, 13-15 which is approximately 10-fold higher than that of IVUS. The aim of the present study was to use intravascular OCT to analyze the time course of neointimal coverage of SES in the chronic phase, and to identify the predictive factors influencing delayed neointimal coverage of stent struts. Background: Late stent thrombosis related to delayed neointimal growth is a major concern after drug-eluting stent (DES) implantation. The time course of neointimal growth and risk factors of uncovered stent struts after sirolimus-eluting stent (SES) was studied using optical coherence tomography (OCT). Methods Study Population Methods and Results:The 60 patients were enrolled and classified into G1 (follow-up period <9 months, n=27), G2 (9-24 months, n=18), and G3 (>25 months, n=15). The time elapsed since SES implantation was associated with a significant increase in mean neointimal area and neointimal thickness, and also with a significant decrease in the number of uncovered stent struts (G1: 14.8%, G2: 11.7%, and G3: 4.1%, P<0.001). However, only 17.6% of implanted SES was completely covered by neointima, even in the G3 period. Small-diameter SES, complex coronary lesions with lipid and calcium content adjacent to stent struts, and diabetes predicted delayed neointimal coverage of SES struts in G1. Conclusions: Neointima inside SES progressively increases after the rou...

Morphological and Quantitative Analysis of Vascular Wall and Neointimal Hyperplasia After Coronary Stenting - Comparison of Bare-Metal and Sirolimus-Eluting Stents Using Optical Coherence Tomography -

“…For example, the cause of late-or very-late stent thrombosis after DES implantation during the convalescent phase is not well understood, but recently, late malapposition, uncovered stent struts, and positive vessel remodeling have been identified, by IVUS and OCT analysis, as latent factors after DES implantation. [24][25][26][27][28][29] In the present study, the rate of malapposition and uncovered stent struts in the SES group was significantly higher than in the BMS group. The RESTART study, which examined stent thrombosis after SES implantation, showed that PSS visualized by coronary angiography (suggesting late malapposition) relates to very-late stent thrombosis.…”

Optical Coherence Tomography Is Superior to Intravascular Ultrasound for Diagnosis of Distal-Type Chronic Thromboembolic Pulmonary Hypertension

“…3,4,10 OCT is an interferometer-based imaging modality that produces a 2-D image of optical scattering from internal tissue microstructures with a high resolution of approximately 10-20 μm, 10-fold higher than that of IVUS. 11- 13 In the present study, we compared OCT with IVUS images in patients with CTEPH during PTPA.…”

Inter-Scan Reproducibility of Geometric Coronary Artery Measurements Using Frequency-Domain Optical Coherence Tomography

“…11) Several studies have investigated the accuracy of quantitative OCT measurements. [12][13][14][15] When OCT was performed in a plexiglass phantom manufactured with a precision of 10 μm, the OCT measurement correlated extremely well with the real luminal dimension (relative standard deviation 1.8%, r = 1.000, intercept 0.01, slope 1.02). 4) In addition, OCT measurement demonstrated a high correlation with IVUS in vivo (R 2 = 0.82, P < 0.001).…”