Impact of bioresorbable versus permanent polymer on longterm vessel wall inflammation and healing: a comparative drug-eluting stent experimental study

Five-year clinical outcomes of a 2.25 mm sirolimus-eluting stent in Japanese patients with very small coronary artery disease: final results of the CENTURY JSV study

The aim of this study is to evaluate the long-term safety and efficacy of the 2.25 mm bioresorbable-polymer sirolimus-eluting Ultimaster stent in a Japanese patient population. Treatment of coronary artery disease in very small vessels is associated with an increased risk for cardiac events. The CENTURY JSV study is a prospective, multicenter, single-arm study. Seventy patients with stable and unstable coronary artery disease with a coronary lesion eligible for implantation with a 2.25 mm stent were enrolled in this study. Patients underwent clinical follow-up through 5-year after the PCI procedure. The mean age was 70.4 ± 9.2 years. The prevalence of diabetes mellitus was 37.1%, all not insulin dependent. The incidence of major adverse cardiac events, defined as cardiac death, target vessel myocardial infarction (MI), and clinically driven target lesion revascularization (CD-TLR) at 5 years was 5.7%. A non-Q wave MI was noted in 1.4% and 4.3% underwent a CD-TLR. There was no stent thrombosis during the entire follow-up period. No cardiac events were reported between 2 and 5 years. This is the first study to demonstrate safety and effectiveness for 5 years after treatment of very small coronary disease with 2.25 mm-diameter DES.Clinical trial registration: UMIN000012928.

2-Year Results With a Sirolimus-Eluting Self-Expanding Stent for Femoropopliteal Lesions: The First-in-Human ILLUMINA Study

OBJECTIVES

The aim of the study was to assess 24-month efficacy and safety of a novel drug-eluting stent (DES) for femoropopliteal interventions with an innovative stent design and abluminal reservoir technology releasing the amphilimus formulation (sirolimus plus fatty acid) for efficient drug transfer and optimized release kinetics.

BACKGROUND

DES releasing paclitaxel exhibited good patency rates after femoropopliteal interventions. No benefit has been reported when sirolimus or everolimus were used for antiproliferative stent coating.

METHODS

Within a multicenter, first-in-man, single-arm study, 100 patients with symptomatic femoropopliteal disease (Rutherford category 2-4, mean lesion length 5.8 ± 3.9 cm, 35.0% total occlusions) were treated with the NiTiDES stent (Alvimedica). Two-year follow-up included assessment of primary patency (defined as absence of clinically driven target lesion revascularization or binary restenosis with a peak systolic velocity ratio >2.4 by duplex ultrasound), safety, functional, and clinical outcomes.

RESULTS

At 24 months, Kaplan-Meier estimates of primary patency and freedom from clinically driven target lesion revascularization were 83.4% (95% CI: 73.9%-89.6%) and 93.1% (95% CI: 85.3%-96.9%), respectively. Over the study period, 3 deaths were reported with no major limb amputation. Functional and clinical benefits were sustained, as 82.1% of patients fell into Rutherford category 0 or 1 at 24 months, which was associated with preserved improvements in all walking disability questionnaire scores.

CONCLUSIONS

The 2-year results of the ILLUMINA (Innovative siroLimus seLf expanding drUg-eluting stent for the treatMent of perIpheral disease: evaluation of safety aNd efficAcy) study demonstrate a sustained treatment benefit with a novel sirolimus-eluting stent that also compares favorably to other femoropopliteal intervention trials. Head-to-head comparisons of NiTiDES with a paclitaxel-based DES are warranted. (The ILLUMINA Study [ILLUMINA]; NCT03510676).

Inflammation as a determinant of healing response after coronary stent implantation

Cardiovascular disease remains the leading cause of death and morbidity worldwide. Inflammation plays an important role in the development of atherosclerosis and is associated with adverse clinical outcomes in patients after percutaneous coronary interventions. Data on stent elements that lead to excessive inflammatory response, proper identification of high-risk patients, prevention and treatment targeting residual inflammatory risk are limited. This review aims to present the role of inflammation in the context of evolving stent technologies and appraise the potential imaging modalities in detection of inflammatory response and anti-inflammatory therapies.

Comparative preclinical evaluation of a polymer-free sirolimus-eluting stent in porcine coronary arteries

Background:

Polymer-free drug-eluting stents (DES) without permanent-polymer coating may be associated with rapid vessel healing, providing a rationale to reduce dual-antiplatelet therapy (DAPT). The aim of the current study was to compare vessel healing of a polymer-free sirolimus-eluting stent (PF-SES), its bare metal stent (BMS) analogue to a permanent polymer-based sirolimus-eluting stent (SES) with proven effectiveness in porcine coronary arteries.

Material and methods:

An ultrathin-strut cobalt–chromium PF-SES, its BMS analogue and an SES with a permanent polymer were used to study vessel healing and their antistenotic potential. Stents were implanted in porcine coronary arteries for histopathologic analysis at 7, 28 and 180 days.

In an additional in vitro study, the thrombogenicity of PF-SES was compared with a fluoropolymer-coated everolimus-eluting stent (EES) which demonstrated low stent thrombosis rates in numerous studies.

Results:

In the animal study, neointimal growth and injury scores were minimal and inflammation scores were low in the neointima and adventitia in all study groups. After 28 days, neointimal area was lowest in PF-SES when compared with SES and BMS (1.48 ± 0.55 mm² versus 2.43 ± 0.69 mm² versus 1.90 ± 0.85 mm², respectively, p < 0.05) and endothelialization of luminal surfaces was nearly complete in all groups, though SES show the least coverage with occasional adherent luminal inflammatory cells (p > 0.05). At 180 days, neointimal area and thickness were most pronounced in SES (p < 0.05) and comparable with BMS implantations, which were characterized by nearly completed vessel healing. PF-SES and BMS had complete endothelialization, absence of fibrin and sustained low inflammatory reaction when compared with the permanent polymer-based SES (inflammation score: PF-SES 0.41 ± 0.74 versus SES 2.52 ± 1.72 versus BMS 0.30 ± 0.65, respectively, p < 0.05 BMS versus SES). Granuloma formation and fibrin accumulation were most pronounced in SES but did not reach statistical significance, p > 0.05). In the in vitro thrombogenicity study, the PF-SES confirmed comparable antithrombogenic properties with regard to the parameters fibrin and platelet binding, and platelet aggregation when compared with the EES.

Conclusions:

As compared with BMS, the ultrathin-strut cobalt–chromium PF-SES showed similar endothelialization at 28 days and comparable healing characteristics at 180 days efficacious inhibition of neointimal proliferation in porcine coronary arteries with low inflammation responses and a BMS-like endothelialization at 180 days. In addition, in an in vitro model, the PF-SES also confirmed low thrombogenicity as compared with the EES.

Balloons and Stents and Scaffolds: Preclinical Evaluation of Interventional Devices for Occlusive Arterial Disease

Atherosclerosis places a significant burden on humankind; it is the leading cause of mortality globally, and for those living with atherosclerosis, it can significantly impact quality of life. Fortunately, treatment advances have effectively reduced the morbidity and mortality related to atherosclerosis, with one such modality being percutaneous intervention (PCI) to open occluded arteries. Over the 40-year history of PCI, preclinical models have played a critical role in demonstrating proof of concept, characterizing the in vivo behavior (pharmacokinetics, degradation) and providing a reasonable assurance of biologic safety of interventional devices before entering into clinical trials. Further, preclinical models may provide insight into the potential efficacy of these devices with the appropriate study design and end points. While several species have been used in the evaluation of interventional devices, the porcine model has been the principal model used in the evaluation of safety of devices for both coronary and endovascular treatments. This article reviews the fundamentals of permanent stents, transient scaffolds, and drug-coated balloons and the models, objectives, and methods used in their preclinical evaluation.

Polymer-free versus durable polymer drug-eluting stents in patients with coronary artery disease: A meta-analysis

Background

Polymer-free drug-eluting stents (PF-DES) were introduced with the aim of reducing the risk of stent thrombosis associated with durable polymer drug-eluting stents (DP-DES). The comparison of safety and efficacy profiles between these two stent platforms remains unclear.

Materials and methods

We conducted electronic database searches for randomized controlled trials (RCTs) comparing patients treated with either PF-DES or DP-DES. Outcomes included definite or probable stent thrombosis (ST), myocardial infarction (MI), cardiac death, all-cause death, target lesion revascularization (TLR), and target vessel revascularization (TVR). A random-effects model was used to derive risk ratios (RRs) with 95% confidence intervals (CIs). Subgroup analyses based on different variables were also performed. After screening a total of 1026 articles, the present meta-analysis included 13 RCTs comprising 8021 patients.

Results

No significant differences were found for the risks of definite or probable ST (RR, 0.94; 95% CI, 0.62–1.43; P = 0.77), MI (RR, 1.06; 95% CI, 0.85–1.33; P = 0.61), cardiac death (RR, 0.98; 95% CI, 0.80–1.21; P = 0.88), all-cause death (RR, 0.87; 95% CI, 0.76–1.00; P = 0.06), TLR (RR, 1.12; 95% CI, 0.94–1.33; P = 0.22), and TVR (RR, 1.18; 95% CI, 0.87–1.61; P = 0.29). Similarly, no significant differences were found for all outcomes regardless of anti-proliferative drug, except for an increased risk of TLR for polymer-free paclitaxel-eluting stents compared with DP-DES (RR, 2.32, 95% CI, 1.30–4.14; P = 0.005).

Conclusions

Our findings showed that PF-DES and DP-DES confer equivalent safety and efficacy profiles, with similar rates of stent thrombosis.

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Polymer-free and durable polymer drug-eluting stents confer similar safety and efficacy profiles.

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There were comparable rates of stent thrombosis between the two stent platforms.

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Further trials with greater length of follow-up are warranted to assess long-term safety and efficacy outcomes.

Evolution of the SYNERGY bioresorbable polymer metallic coronary stent

The SYNERGY stent is composed of thin, platinum-chromium metal alloy struts and an ultrathin, bioabsorbable poly-DL-lactide-co-glycolide polymer limited to the abluminal strut surface which elutes everolimus prior to complete resorption within 3–4 months. SYNERGY was designed to reduce inflammation and facilitate stent healing compared with permanent polymer drug eluting stents. This review summarizes the preclinical and clinical development of SYNERGY, its integration into clinical practice and future directions.