A bioabsorbable everolimus-eluting coronary stent system for patients with single de-novo coronary artery lesions (ABSORB): a prospective open-label trial

Background A fully bioabsorbable drug-eluting coronary stent that scaffolds the vessel wall when needed and then disappears once the acute recoil and constrictive remodelling processes have subsided has theoretical advantages. The bioasorbable everolimus-eluting stent (BVS) has a backbone of poly-L-lactic acid that provides the support and a coating of poly-D,L-lactic acid that contains and controls the release of the antiproliferative agent everolimus. We assessed the feasibility and safety of this BVS stent. Methods In this prospective, open-label study we enrolled 30 patients who had either stable, unstable, or silent ischaemia and a single de-novo lesion that was suitable for treatment with a single 3 . 0x12 mm or 3 . 0x18 mm stent. Patients were enrolled from four academic hospitals in Auckland, Rotterdam, Krakow, and Skejby. The composite endpoint was cardiac death, myocardial infarction, and ischaemia-driven target lesion revascularisation. Angiographic endpoints were available for 26 patients and intravascular-ultrasound endpoints for 24 patients. Clinical endpoints were assessed in all 30 patients at 6 and 12 months. In a subset of 13 patients, optical coherence tomography was undertaken at baseline and follow-up. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00300131. Findings Procedural success was 100% (30/30 patients), and device success 94% (29/31 attempts at implantation of the stent). At 1 year, the rate of major adverse cardiac events was 3 . 3%, with only one patient having a non-Q wave myocardial infarction and no target lesion revascularisations. No late stent thromboses were recorded. At 6-month follow-up, the angiographic in-stent late loss was 0 . 44 (0.35) mm and was mainly due to a mild reduction of the stent area (-11 . 8%) as measured by intravascular ultrasound. The neointimal area was small (0 . 30 [SD 0 . 44] mm(2)), with a minimal area obstruction of 5.5%. Interpretation This study shows the feasibility of implantation of the bioabsorbable everolimus-eluting stent, with an acceptable in-stent late loss, minimal intrastent neointimal hyperplasia, and a low stent area obstruction

Monitoring In Vivo Absorption of a Drug-Eluting Bioabsorbable Stent With Intravascular Ultrasound-Derived Parameters A Feasibility Study

Objectives The aim of this study was to investigate the feasibility of using quantitative differential echogenicity to monitor the in vivo absorption process of a drug-eluting poly-l-lactic-acid (PLLA) bioabsorbable stent (BVS, Abbott Vascular, Santa Clara, California). Background A new bioabsorbable, balloon-expanded coronary stent was recently evaluated in a first-in-man study. Little is known about the absorption process in vivo in diseased human coronary arteries. Methods In the ABSORB (Clinical Evaluation of the BVS everolimus eluting stent system) study, 30 patients underwent treatment with the BVS coronary stent system and were examined with intracoronary ultrasound (ICUS) after implantation, at 6 months and at 2-year follow-up. Quantitative ICUS was used to measure dimensional changes, and automated ICUS-based tissue composition software (differential echogenicity) was used to quantify plaque compositional changes over time in the treated regions. Results The BVS struts appeared as bright hyperechogenic structures and showed a continuous decrease of their echogenicity over time, most likely due to the polymer degradation process. In 12 patients in whom pre-implantation ICUS was available, at 2 years the percentage-hyperechogenic tissue was close to pre-implantation values, indicating that the absorption process was either completed or the remaining material was no longer differentially echogenic from surrounding tissues. Conclusions Quantitative differential echogenicity is a useful plaque compositional measurement tool. Furthermore, it seems to be valuable for monitoring the absorption process of bioabsorbable coronary stents made of semi-crystalline polymers. (J Am Coll Cardiol Intv 2010;3:449-56) (C) 2010 by the American College of Cardiology Foundatio