First-in-man evaluation of the MOMO cobalt-chromium carbon-coated stent

Surface engineering at the nanoscale: A way forward to improve coronary stent efficacy

Coronary in-stent restenosis and late stent thrombosis are the two major inadequacies of vascular stents that limit its long-term efficacy. Although restenosis has been successfully inhibited through the use of the current clinical drug-eluting stent which releases antiproliferative drugs, problems of late-stent thrombosis remain a concern due to polymer hypersensitivity and delayed re-endothelialization. Thus, the field of coronary stenting demands devices having enhanced compatibility and effectiveness to endothelial cells. Nanotechnology allows for efficient modulation of surface roughness, chemistry, feature size, and drug/biologics loading, to attain the desired biological response. Hence, surface topographical modification at the nanoscale is a plausible strategy to improve stent performance by utilizing novel design schemes that incorporate nanofeatures via the use of nanostructures, particles, or fibers, with or without the use of drugs/biologics. The main intent of this review is to deliberate on the impact of nanotechnology approaches for stent design and development and the recent advancements in this field on vascular stent performance.

Biodegradable polymer-based, argatroban-eluting, cobalt-chromium stent (JF-04) for treatment of native coronary lesions: final results of the first-in-man study and lessons learned

AIMS

The aim of the study was to investigate the six-month angiographic and nine-month clinical follow-up outcomes in a first-in-man study using the biodegradable polymer-based cobalt-chromium argatroban-eluting stent (JF-04) for treatment of native coronary atherosclerotic lesions.

METHODS AND RESULTS

A total of 31 patients with either stable or unstable angina, or silent myocardial ischaemia, exhibiting de novo coronary lesions were enrolled at seven Japanese sites. The lesions were treated with the JF-04 stent after predilatation. The primary endpoint was angiographic in-stent late loss six months after implantation. The secondary endpoints included angiographic restenosis and in-stent volume obstruction by intravascular ultrasound at six months and target vessel failure (TVF) at nine months. Procedural success was achieved in 100% of cases. At six months, angiographic in-stent late loss was 1.01±0.48 mm and binary restenosis was observed in nine cases (29.0%). Among these restenotic cases, most (n=8) demonstrated advanced angiographic restenosis patterns, including diffuse/proliferative restenosis and total occlusion. At nine months, TVF was observed in four cases (12.9%), exclusively attributed to target vessel revascularisation.

CONCLUSIONS

This argatroban-eluting stent failed to inhibit neointimal hyperplasia sufficiently, despite the theoretical benefits and promising clinical experience with local drug delivery.

Prospective multi-center registry to evaluate efficacy and safety of the newly developed diamond-like carbon-coated cobalt-chromium coronary stent system

The purpose of this multi-center, non-randomized, and open-label clinical trial was to determine the non-inferiority of diamond-like carbon (DLC)-coated cobalt–chromium coronary stent, the MOMO DLC coronary stent, relative to commercially available bare-metal stents (MULTI-LINK VISION^®). Nineteen centers in Japan participated. The study cohort consisted of 99 patients from 19 Japanese centers with single or double native coronary vessel disease with de novo and restenosis lesions who met the study eligibility criteria. This cohort formed the safety analysis set. The efficacy analysis set consisted of 98 patients (one case was excluded for violating the eligibility criteria). The primary endpoint was target vessel failure (TVF) rate at 9 months after stent placement. Of the 98 efficacy analysis set patients, TVF occurred in 11 patients (11.2 %, 95 % confidence interval 5.7–19.2 %) at 9 months after the index stent implantation. The upper 95 % confidence interval for TVF of the study stent was lower than that previously reported for the commercially available MULTI-LINK VISION^® (19.6 %), demonstrating non-inferiority of the study stent to MULTI-LINK VISION^®. All the TVF cases were related to target vascular revascularization. None of the cases developed in-stent thrombosis or myocardial infarction. The average in-stent late loss and binary restenosis rate at the 6-month follow-up angiography were 0.69 mm and 10.5 %, respectively, which are lower than the reported values for commercially available bare-metal stents. In conclusion, the current pivotal clinical study evaluating the new MOMO DLC-coated coronary stent suggested its low rates of TVF and angiographic binary restenosis, and small in-stent late loss, although the data were considered preliminary considering the small sample size and single arm study design.

Clinical and angiographic outcomes following first-in-man implantation of a novel thin-strut low-profile fixed-wire stent: the Svelte Coronary Stent Integrated Delivery System first-in-man trial

AIMS

The Svelte Stent Integrated Delivery System (IDS) is a novel fixed-wire thin-strut cobalt-chromium stent characterised by a very low entry profile. The aim of the present study is to evaluate the safety and the feasibility of the Svelte stent IDS implantation in humans.

METHODS AND RESULTS

The present investigation is a prospective, multicentre non-randomised single-arm study. The primary endpoint was freedom from major adverse cardiac events (MACE) at 30 days post-procedure. Invasive follow-up was scheduled at six months post implantation. A total of 47 patients were enrolled and serial OCT imaging was performed in a subgroup of 18 patients. At the index procedure the lesion success rate was 97.9% (46 patients), the mean acute gain was 1.56 ± 0.43 mm with a mean minimum lumen diameter of 2.48 ± 0.43 mm. Post-implantation OCT imaging revealed a minimal mean prolapse area (0.10 ± 0.06 mm²), mean incomplete stent apposition area (0.12 ± 0.13 mm²) and mean intraluminal mass area (0.05 ± 0.03 mm²). Edge dissections were reported in eight cases (mean dissection width 0.17 ± 0.07 mm proximally and 0.25 ± 0.24 mm distally). At 30-day clinical follow-up, one case of myocardial infarction was reported. At six months, the angiographic mean in-stent late loss was 0.95 ± 0.76 mm. By OCT, a high percentage of struts was covered (97.6 ± 15.00 %) with a mean neointimal thickness of 0.31 ± 0.14 mm, all edge dissections were clinically silent and healed. Target lesion revascularisation (TLR) occurred in 11 patients (23.4%) and clinically driven TLR in three of these patients (6.4%). No cases of death or stent thrombosis were reported during the study.

CONCLUSIONS

Implantation of the Svelte stent IDS was observed to be safe, feasible and associated with a low acute vascular injury and a high percentage of strut coverage at 6-month follow-up.