With ongoing concerns related to the possibility of thrombosis and death following implantation of a drug-eluting stents (DES), the sector has been focusing as much on follow-on drug therapy as the stent itself. These issues include the role of anti-coagulation therapy, how long it should be administered, and the patient's role in continuing this therapy, as prescribed.
Responding to these issues, the American Heart Association (Dallas), the American College of Cardiology (Washington) and the Society of Cardiovascular Angiography and Intervention (Washington) this month released updated guidelines, for those issued in 2005, concerning percutaneous coronary intervention (PCI) and follow-on drug compliance, emphasizing better conversation between cardiologist and patient.
The guidelines say that PCI is effective in treating myocardial infarction (MI) and angina, but that research has "identified a few caveats," according to a statement issued by the three groups. Among these "caveats" is that drug-eluting stents come with "a slightly higher risk of clots forming inside them," and the need for patients to receive "a combination of anti-clotting medicines for a year or longer after their procedure," the statement putting emphasis on the patient's "responsibility" in complying with such a regimen. It says that DES should be "considered" as an alternative to a bare-metal stent in patients with "a favorable effectiveness and safety profile," but that there must be some certainty that the patient really can follow this regimen.
Thus, "before implanting a drug-eluting stent, the interventional cardiologist should discuss with the patient the need for and the duration of dual antiplatelet therapy (clopidogrel plus aspirin) and confirm the patient's ability to comply with the recommended therapy." The guidelines writers also emphasize this means "active involvement of the patient with this follow-on treatment, suggesting that, to date, this has not been a large part of doctor/patient conversations.
It continues: "Continuing dual antiplatelet therapy is so important that the guidelines take into consideration future medical procedures that may require the therapy to be interrupted. If patients face additional surgery, recommendations call for implanting a bare-metal stent or performing a balloon angioplasty with provisional stent implantation instead of the routine use of a DES.
Additionally, the guidelines discuss the "timing" of PCI in certain groups and settings, primarily the use of "facilitated" PCI by performing fibrinolysis immediately before being transferred for PCI; and points to research citing the use of PCI for dealing with clogged vessels "in patients with one- or two- vessel coronary artery disease who are asymptomatic without evidence of ongoing ischemia if the procedure is performed between 24 hours and 28 days after a heart attack."
It says in this case that PCI is not recommended if the patients are "hemodynamically and electrically stable and have no ongoing or easily provoked chest pain. However for these patients or, a patient who responds favorably to initial fibrinolysis [treatment with a clot-busting drug], some physicians might use PCI selectively for those who don't continue to do well on drug therapy alone."
The guidelines also address recent research indicating that medical therapy is as effective as PCI/stenting. It says: "Members of the writing group said the balance of evidence supports an early invasive strategy for PCI for patients with unstable angina or non-ST elevation heart attack, who are at moderate and higher risk, but noted one recent study suggests that in those patients who are initially stabilized on comprehensive medical therapy, PCI may be used selectively" — the term "selectively" suggesting that it need not always be used. And the statement also says that this "selective invasive strategy" received "a lower level of recommendation than that given to early PCI."
The guidelines also reemphasize a variety of "secondary" prevention of MI, including the avoidance of smoking and second-hand smoke, the control of cholesterol and blood pressure and the need for continued coordination of primary care clinicians and specialists in the treatment of diabetes.----
Texas doc says Cypher, Taxus DES products infringe his patent
Wall Cardiovascular Technologies (Marshall, Texas) has filed a complaint in the Marshall Division of the U.S. District Court for the Eastern District of Texas, alleging infringement of a coronary stent technology patent by Boston Scientific (Natick, Massachusetts) and Johnson & Johnson (J&J; New Brunswick, New Jersey.
According to the complaint, U.S. patent No. 6,974,475 was issued in December of 2005 to W. Henry Wall, MD, founder of Wall Cardiovascular, for an invention titled "Angioplasty Stent" and that all rights to the '475 patent were assigned to Wall Cardiovascular on Nov. 2, 2007.
Wall is claiming that some of Boston Scientific's products are based on technology covered by the patent issued to Wall Cardiovascular and that in 1984 he conceived of the technology covered in the '475 patent, as well as several additional patents on related technology and medical devices.
The complaint states that Boston Scientific's Taxus DES "and other products and services related to coronary, carotid and peripheral stents" infringe Wall's patent and that Boston Scientific is "contributing to and inducement of others to manufacture, use, sell, import, and/or offer for sale of infringing products." The complaint says that Boston Scientific in September 2005 "attempted to license from Dr. Wall the patent application that subsequently issued as the '475 patent." But when the parties could reach no agreement, the company then proceeded to develop and market its infringing products, according to the allegations.
The lawsuit alleges also that J&J has also infringed the '475 patent through its Cypher DES product — made by Cordis (Miami Lakes, Florida), a unit of J&J — and other products and services related to coronary, carotid and peripheral stents.
"As early as 1988, Dr. Wall contacted J&J and Cordis to inform them of his recently filed patent application related to stent technology," the suit says. "Dr. Wall was seeking a partner with whom to jointly commercialize his invention."
Wall claims to have had periodic contact with both J&J and Cordis regarding his pending application, and within weeks of the issuance of the '475 patent, Wall's patent attorney contacted J&J. By that time, J&J had acquired Cordis. The court documents state that J&J agreed to meet with Wall to discuss the possibility of partnering to jointly commercialize the patented technology or to take a license under the '475 patent.
"Ultimately, J&J decided to forego a license under the '475 patent," the suit claims. Wall is an Air Force veteran and according to the lawsuit is "one of the early pioneers of stent technology."
An oral surgeon, Wall was assistant clinical professor at the Emory University School of Dentistry (Atlanta) in the early 1980s.
"Dr. Wall's interest in angioplasty and stent technology was piqued when the first angioplasty in the U.S. was performed at Emory Hospital during Dr. Wall's tenure there," the suit says. "Upon reading of the breakthroughs in angioplasty that were taking place at Emory Hospital, Dr. Wall began to develop methods and devices for preventing the restenosis of vessels following angioplasty."
Wall is seeking enhanced damages, claiming that the infringement has been willful. He is represented by Stephen Susman of the law firm of Susman Godfrey (Houston).----
Secretoneurin found to be possible therapy for stroke
In a new study, a team of researchers from the Academia Sinica, Republic of China, and the China Medical University, Republic of China, reported discovering a neuroprotective role for Secretoneurin (SN) — a neural protein with various roles in the normal functioning of the brain and nervous system function — in a rat model of stroke.
Previously, SN was found to increase blood vessel formation in mouse corneas, and its production is increased following transient brain ischemia in gerbils.
In the new study, SN production by rats was found to be increased in neuronal and endothelial brain cells following the induction of ischemia in the brain. In vitro, SN treatment improved the survival of primary brain cell cultures subjected to oxygen/glucose deprivation. Cell rescue was dependent on SN-induced expression of proteins that prevent a form of cell death called apoptosis.
Furthermore, when rats with ischemia-induced stroke were injected with SN, they exhibited reduced cerebral tissue death, improved motor performance, and enhanced brain function. In addition, stem cell targeting to the brain and subsequent blood vessel formation were also incited by SN injection in these animals.
From these results, the authors suggest that SN holds promise as a powerful small-molecule drug in the treatment of stroke.