Serial Observation of Drug-Eluting Absorbable Metal Scaffold

Abstract

1,2 stent thrombosis, especially at the late phase, remains a major concern, probably related to delayed healing, chronic inflammation, and impaired endothelialization.3 Furthermore, metallic stents are associated with artifacts in noninvasive imaging of MRI or multislice computed tomography, impairment of vessel geometry, and often jailing of side branches. Because of their permanent nature, metallic stents can also induce neoatherosclerosis during long-term follow-up. 4 Polymeric bioabsorbable temporary scaffolds have been developed to resolve these limitations. Second-generation bioabsorbable everolimus-eluting scaffold systems (BVS 1.1, ABSORB; Abbott Vascular, Santa Clara, CA) have shown a late lumen loss at 12 months similar to that seen with permanent everolimus-eluting stents (EES), along with a major adverse cardiac event rate of 7.1%. 5 In addition, unlike permanent metallic stents, interesting observations of the bioresorbable vascular scaffold technology are vessel lumen enlargement during follow-up and the ability of the vessel to Background-The drug-eluting absorbable metal scaffold has demonstrated feasibility, safety, and promising clinical and angiographic outcomes at 12 months in human coronary arteries. This study aimed to evaluate the degradation rate and long-term vascular responses to drug-eluting absorbable metal scaffold. Methods and Results-BIOSOLVE-I was a multicenter, single-arm, first-in-man trial assessing the safety and performance of drug-eluting absorbable metal scaffold in 46 patients with coronary artery disease. Patients who underwent serial invasive imaging, such as quantitative coronary angiography, intravascular ultrasound, and optical coherence tomography, at 6 and 12 months were included in this study. From postimplantation to follow-up, arterial curvature and angulation were significantly increased by the degradation process. The greatest increase was seen from postimplantation to 6 months. The systolic-diastolic changes of the curvature and angulation gradually improved throughout the follow-up period. At the site of implantation, vasoconstriction (−10% mean reduction) was observed during the acetylcholine test at 6 months. The average percent hyperechogenicity of the scaffolded segments showed a continuous decrease over time, with the most pronounced changes within the first 6 months (from 22.1±7.0% to 15.8±3.7%; P<0.001). Struts discernible on optical coherence tomography at 6 and 12 months showed full neointimal coverage, with stabilization of the mean scaffold area from 6 to 12 months. Furthermore, the mean neointimal area (1.55±0.51 versus 1.58±0.34 mm 2 ; P=0.794) remained unchanged from 6 to 12 months. Conclusions-This

In vitroandin vivocorrosion properties of new iron–manganese alloys designed for cardiovascular applications

“…Therefore, they can be compared only inferiorly both to bare metal or drug eluting stents. 17,18 To expedite the corrosion of iron-based degradable implants iron-manganese alloys have been developed. Mn is the minor alloying component (<10%).…”

“…Pure iron stents were tested in different cellculture and animal models [10][11][12] and magnesium or magnesium-based alloy systems were implemented and tested in various in vitro and in vivo models. [13][14][15][16] Although the addition of antiproliferative drugs has recently proven to be beneficial in clinical trials with absorbable metal scaffolds, 17 to date, none of the approaches has reached routine clinical practice. Uncoated pure magnesium or magnesium based alloys exhibited ex stent restenosis and medial disruption leading to local adverse effects.…”

Assessing Bioresorbable Coronary Devices

“…The highest value of strain in the cross-section was taken as the strain level of the spot. The Echogenicity parameters have been shown to be able to detect temporal changes in the gray-level intensities for Absorb and DREAMS, being putatively correlated to scaffold degradation over time (8,35).…”

Effect of non‐compliant balloon postdilatation on magnesium‐based bioresorbable vascular scaffolds

“…No definite or probable scaffold thrombosis was observed with Magmaris™. Previous generations of magnesium‐based scaffolds showed no scaffold thrombosis up to 3 years . However, the patient cohorts included in these studies are relatively small.…”