ClinicalEarly vascular healing with rapid breakdown biodegradable polymer sirolimus-eluting versus durable polymer everolimus-eluting stents assessed by optical coherence tomography☆,☆☆
Introduction
First-generation drug-eluting stents (DES) deliver high clinical efficacy at the collateral cost of delayed healing of the stented arterial segment [1]. Pathological studies have suggested that the absence of stent strut tissue coverage and the persistence of fibrin deposition are the pathological hallmarks of delayed arterial healing and mechanistically underlie the slight excess of very late stent thrombosis seen with these devices.
The ITRIX biodegradable polymer sirolimus-eluting stent (BP-SES) is a novel device coated with an ultra-thin layer (5 μm) of rapid breakdown biodegradable polymer designed to degrade completely in approximately 8 weeks. It is hypothesized that both the faster release kinetics of the antiproliferative drug and the early loss of biodegradable polymer coating may be associated with an earlier vascular healing response expressed by a higher degree of stent strut coverage. In addition, the durable polymer everolimus-eluting stent (EES) has shown signs of improved early vessel healing in preclinical study [2] and recently has received approval in Europe for implantation with shorter duration (3 months) of dual antiplatelet therapy [3].
High-resolution intracoronary optical diagnostics allow precise assessment of stent coverage and stent apposition permitting insights into vascular healing patterns in vivo [4], [5]. However few studies have examined vessel healing at an early time point after stenting. Accordingly we compared rapid breakdown BP-SES with the durable polymer EES using optical coherence tomography (OCT) at 4 months.
Section snippets
Study population, devices, randomization and intervention protocol
The Polymer Degrading-Sirolimus Eluting-Coronary Stent Trial (PILOT) was a prospective, multi-center pilot trial, enrolling a total of 20 patients, who were randomly assigned to treatment with either BP-SES or EES. Eligible patients (age, ≥ 18 years and < 80 years) had angina pectoris and/or objective signs of ischemia, in the presence of a ≥ 50% diameter stenosis de novo native coronary artery lesion. Key exclusion criteria included patients with cardiogenic shock, left ventricular function < 40%,
Baseline patient, lesion and procedural characteristics
Patient study flow is shown in Fig. 1. A total of 11 patients were allocated to BP-SES and 9 patients allocated to EES. Baseline characteristics of the patients, procedure, and lesions are shown in Table 1. There were no significant differences between two groups.
Clinical outcomes
One patient in EES group underwent revascularization for restenosis at the proximal stent margin. Otherwise there were no clinical events in either group at 4 months follow-up.
OCT results
Fifteen patients returned for intravascular imaging surveillance; 4 patients in the BP-SES and 1 in the EES group declined.
Coverage and apposition of the stent struts were analyzed with strut- and patient-level. The spread-out-vessel graphics showing the spatial distribution and coverage of individual analyzed struts are shown in Fig. 2. There were fewer total struts analyzed in the BP-SES compared with the EES group (545 struts in 7 patients in BP-SES group versus 954 struts in 8 patients in
Discussion
The main findings of the current pilot study are that (1) although a novel rapid breakdown biodegradable polymer sirolimus-eluting stents as compared to a durable polymer everolimus-eluting stent showed evidence of higher strut-level coverage as evaluated by OCT at 4 months follow-up, these differences were not significant when adjustment was made for intra-patient clustering; (2) heterogeneity analysis revealed no difference in strut coverage patterns between the 2 stents; and (3) there was no
Conclusions
A novel rapid-breakdown BP-SES as compared to durable polymer EES showed similar degree of early stent strut coverage as assessed by OCT at 4 months, though coverage patterns were more homogeneous with BP-SES. No differences in ability to suppress neointimal hyperplasia after stent implantation between the 2 stents were observed.
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Randomised comparison of vascular response to biodegradable polymer sirolimus eluting and permanent polymer everolimus eluting stents: An optical coherence tomography study
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2016, Cardiovascular Revascularization MedicineCitation Excerpt :Neointimal hyperplasia was calculated as the average of thickness of the tissue coverage of the luminal side of each strut. Coverage and apposition of the stent struts were analysed with strut- and cross section-level [10,11]. Struts were classified as malapposed if protruding into the lumen at a distance greater than the sum of the strut and polymer thickness (71 μm and 91 μm for the 2.25, 2.5 and 3.0 stent diameter and 3.5, 4.0 stent diameter respectively) plus the minimal axial OCT resolution (20 μm) Fig. 2.
Cell viability of fibroblasts to pifenidone and sirolimus: A future concept for drug eluting stents
2014, International Journal of PharmaceuticsCitation Excerpt :However, there is still no long term drug eluting product on the market. Drug eluting stents were found to be responsible for early vessel wound healing (Abhyankar et al., 2013; Tada et al., 2013). Moreover, it was observed that when two sirolimus eluting stents were placed proximally they formed a fibrinous tissue membrane (Yamada and Takahashi, 2013).
Long-term outcomes of biodegradable polymer versus durable polymer drug-eluting stents in patients with diabetes a pooled analysis of individual patient data from 3 randomized trials
2013, International Journal of CardiologyCitation Excerpt :This is hypothesized to confer a lower risk of late stent thrombosis, an effect potentially magnified in patients with diabetes. Indeed a number of intravascular imaging studies show encouraging data regarding vessel healing after biodegradable polymer DES implantation in man [25,26]. Our study represents the first analysis of long-term outcomes in patients with diabetes treated with biodegradable polymer DES.
Drug-eluting Stents: Will the transformation to bioabsorption make durable polymers obsolete?
2013, Cardiovascular Revascularization Medicine
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Funding: This study was supported by AMG international GmbH, Germany.
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Conflict of interest: Dr. Kastrati reports received lecture fees from Abbott, Biotronik, Cordis and Medtronic. The remaining authors report no conflicts of interest.