Dr. Julio Palmaz, who with Dr. Richard Schatz patented the balloon-expandable stent, believes that, while the market for stents has evolved from bare metal stents to drug-eluting stents (DES), the inevitable limitation of DES will be that they lead to inflammatory response and that their real drawback is that they create a barrier between tissue and the metal of the stent itself.
A plenary speaker during the XXX Congresso Nazionale Della Societa Italiana Di Cardiologia Invasiva (GISE), Dr Julio Palmaz (University of Texas Health Science Center, San Antonio) predicted that coatings "of any kind" will prove to be the downfall of drug-eluting stents—even the bioerodable polymers or the coatings used on fully bioerodable stents that today represent the next great hope in DES technology. Pointing to the failure of gold-coated stents back in 2000, Palmaz called on stent manufacturers to "learn from the mistakes of the past."
"Any coating, of any kind, will have the potential to [produce] nonspecific inflammatory changes," he predicted.
Dr. Palmaz pointed out that, in a bare metal stent, the positive charges of the metal cause the natural formation of oxides that induce healing. The problem with first generation metal stents, he says, is that the constructions of the stents, and their deployment, cause an interruption of the smooth metal surface that lead to an "unhappy" environment surrounding the stent, leading to restenosis. Dr. Palmaz's focus now, through his own company, is to engineer "advanced metallurgical surface technologies" that address this.
PRLog (Press Release) – Sep 09, 2009 – The global market for coronary stents is owned largely by drug-eluting stents (DES), but the size of the patient pool, the drive for lowered cost, ever-increased efficacy and less trauma are spawning the development of multiple new technologies in coronary stents and competitive anti-restenosis technologies. The global market, products, companies, trends and opportunities are the subject of the 2009 report, "Worldwide Coronary Stents 2009," from MedMarket Diligence
In my regular review of industry press releases, patents (and applications), peer-reviewed journals and other medtech sources, I am occasionally struck by an article or paper that I find compellingly succinct or clear or detailed — or all of the above. The clinical background and technology development of coronary drug-eluting stents are areas I have monitored and published on through different media (most recently through our industry report), so even a particularly clear article may not provide me with more than a confirmation of my understanding. However, I find a geeky need (or social networking compulsion) to pass along such articles to my audience. Such is the article (mobile version) in an August 2009 issue of the Journal of the American Academy of Physician Assistants. See the opening, pithy synopsis:
Coronary atherosclerotic disease remains the leading cause of mortality in the industrialized world. One American dies from coronary heart disease (CHD) every minute, with an estimated 1.2 million MIs occurring annually in the United States.1 With the epidemic of obesity in this country and Americans’ increasingly sedentary lifestyle, more patients are at risk of developing CHD than ever before. Additionally, more patients are developing abnormal lipid profiles at younger ages, including elevated LDL and decreased HDL cholesterol levels. Abnormal lipid profiles are a well-documented risk factor for the development of atherosclerosis. The coupling of abnormal lipid profiles with vascular injury promotes atherosclerosis, causing symptomatic CHD, including angina pectoris and MI. When symptoms can no longer be medically managed, more invasive options, including percutaneous intervention (PCI) and coronary artery bypass grafting (CABG), may be advised. This article reviews the factors leading to development of CHD and the evolution of PCI technology, discusses how to identify which patients are the best candidates for drugeluting stent (DES) implantation, and explains how to maintain patient safety after PCI.
See also the 2009 report from MedMarket Diligence on the global coronary stents market at link.
The August 24, 2009, issue of the "Journal of the American Academy of Physician Assistants" presents a concise, yet accurately detailed view of the full context — coronary heart disease, clinical practice, demographics, complications, etc. — for the use of drug-eluting coronary stents. Having focused on drug-eluting stents (DES) from the product market analysis, I was impressed with the succinct detail of this overview.
"Coronary atherosclerotic disease remains the leading cause of mortality in the industrialized world. One American dies from coronary heart disease (CHD) every minute, with an estimated 1.2 million MIs occurring annually in the United States." continued
The May 2009 MedMarket Diligence Report #C245 details the global market for drug-eluting, bare metal, and other coronary stents.
Different material types, constructions and designs comprise devices for anti-restenosis following interventional cardiology (percutaneous coronary intervention). These include drug-eluting stents (such as those of J&J/Cordis, Boston Scientific, Abbott and Medtronic), the stainless steel or CoCr bare metal stents of J&J/Cordis, Abbott, Sahajanand Medical Technologies, and others. Below is a selection of the anti-restenosis device types and associated descriptions.