Long-term (≥2 years) follow-up optical coherence tomographic study after sirolimus- and paclitaxel-eluting stent implantation: comparison to 9-month follow-up results

Abstract

Many studies have demonstrated that late or very late thrombosis after drug-eluting stent (DES) implantation may be related with incomplete neointimal coverage. We investigated long-term (≥2 years) results of neointimal coverage following sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) implantation using optical coherence tomography (OCT). A follow-up angiography with OCT examination was performed in 29 patients with 32 lesions for more than 2 years (group 1; 1,066 ± 381 days) and 101 patients with 104 lesions at 9 months (group 2; 273 ± 33 days) after the index procedure. The status of neointimal coverage and stent apposition was evaluated. The number of stents with completely covered struts was higher (25.0% in group 1 vs. 13.5% in group 2, P = 0.12). The percentage of uncovered struts (5.4 ± 7.5% in group 1 vs. 8.5 ± 11.6% in group 2, P = 0.19) and that of malapposed strut (0.5 ± 1.4% vs. 1.5 ± 4.2%, respectively, P = 0.19) were lower in group 1. While the percentage of uncovered and malapposed struts were quite similar in the PES groups between the two groups (P = 0.54 and 0.65, respectively), there were lower trends in the percentage of uncovered and malapposed struts in the SES group (P = 0.09 and 0.09, respectively). In conclusion, incomplete neointimal coverage was still observed in a majority of DESs and considerable struts were not covered with neointima even at more than 2 years after DES implantation. The pattern of neointimal coverage between 9-month and 2-year appeared to be somewhat different between PES and SES.

Stent Thrombosis: Incidence, Predictors and New Technologies

“…One possible explanation for such late occurrence is incomplete neointimal coverage as a result of delayed arterial healing, ongoing vessel wall inflammation and late acquired stent malapposition [46–50]. These phenomena have been observed in patients with DES by real-time imaging studies (angioscopy and optical coherence tomography (OCT)) [47, 49–51] and also in some autopsy studies of stented segments in patients with very late ST [46]. Figure 2 demonstrates a definite ST in a patient 18 months following SES implantation and evidence of thrombus on malapposed struts.…”

Quantitative and Qualitative Changes in DES-Related Neointimal Tissue Based on Serial OCT

“…Previous OCT studies reported that the percentage of uncovered struts was 15% at 3 months (19), 8.9% to 13.3% at 6 months (20 -22), and 12.2% at 9 to 12 months after SES implantation (23). In addition, until now, serial or long-term (Ն2 years) follow-up OCT studies after DES implantation were very rare and the number of study patients in those studies was smaller (16,25). As the time interval from stent implantation to follow-up OCT was longer, there was a trend toward decreased rate of uncovered struts in general.…”

Very Late Mycotic Pseudoaneurysm Associated With Drug-Eluting Stent Fracture

“…Recent studies show the lack of endothelial coverage of drug-eluting-stent even years after stent implantation. 2 It is believed that the persistently exposed stent struts may provide a nidus for infection during an episode of bacteremia. However, in this particular case, we postulate that previous stent fracture was a predisposing condition for the infection.…”