Till now metallic stents are used in coronary artery stenting in patients suffering from atherosclerotic arterial blockade in ischaemic heart disease (IHD) i.e. significantly decreased the blood flow to the heart musculature.
The main problem with metallic stents were arterial clogging of the part or thrombosis, life long presence and continued medicine use to prevent thrombosis.
Image of A Drug-Eluting StentRecently, Abbot has developed absorable stents whose 30 days examination results in 101 patients are announced. The stents are called Bioresorabable vascular scaffold (BVS). There was no cases of blood clots (thrombosis), no need for repeat procedures (ischemia-driven target lesion revascularization) and a very low rate of major adverse cardiac events (MACE1 rate of 2.0 percent) at 30 days; as reported in a press release. According to the company 6.9 percent of patients suffered major cardiac events -- including heart attacks -- over a 12-month period, which the device maker described as a low rate.
Image Heart with Coronary ArteriesThe stent was approved in Europe in January, but will not be widely available there until late next year. It was cleared by European regulators even though large so-called pivotal trials have not yet been conducted on the product.
Abbott’s investigational BVS, they call “Absorb” is made of a corn-based bioplastic called polylactic acid (PLA). This same material is being used in a number of other ways, including food packaging, textile fibers and even gift cards. It is a proven bio-compatible material that is also commonly used in medical implants such as dissolving sutures.
The bioresorbable technology is designed to restore blood flow by opening a clogged vessel and providing support until it is healed. Once the vessel can remain open without the extra support, the bioresorbable scaffold is designed to be slowly metabolised by the body, and is completely dissolved over time. Since a permanent implant is not left behind, a vessel treated with BVS has the ability to ultimately move, flex and pulsate similar to an untreated vessel.
The bioresorbable technology delivers everolimus, a drug that inhibits tissue proliferation. Everolimus, developed by Novartis Pharma AG, is a proliferation signal inhibitor, or mTOR inhibitor. Everolimus has been shown to inhibit treated site neointimal growth in the coronary vessels following vascular device implantation, due to its anti-proliferative properties.
Image of StentThe ABSORB trial is a prospective, non-randomized (open label), two-phase study that enrolled 131 patients from Australia, Belgium, Denmark, France, the Netherlands, New Zealand, Poland and Switzerland.
Key endpoints of the study include assessments of safety – major adverse cardiac events and treated site thrombosis rates – at 30 days; six, nine, 12, 18 and 24 months; with additional annual clinical follow-up for up to five years.
Image of Coronary Angioplasty and Stent PlacementOther key endpoints of the study include imaging assessments by angiography, intravascular ultrasound (IVUS), optical coherence tomography (OCT), and other state-of-the-art invasive and non-invasive imaging modalities at six, 12, 18 and 24 months.
Abbott plans to begin a 500-patient pivotal trial in Europe later this year and to conduct a 2,000-patient trial in the United States by the end of 2011. It hopes to seek U.S. approval for the product in 2015, several years before any competitor.
