Study Finds Stents An Effective Alternative to Carotid Surgery
For years, doctors have used stents to clear clogged cardiac vessels and prevent heart attacks. Now there is conclusive evidence these expandable devices can be used to prevent strokes as well.
Abbott Laboratories’ Acculink Carotid stents were used in a clinical study that concluded that carotid stenting and surgery are both safe and effective treatments for people at risk of stroke. Photo courtesy of Abbott Laboratories.
Results of a 10-year study found that carotid stenting and surgery are both safe and effective treatments for people at risk of a stroke. The finding gives physicians another tool to prevent strokes, the nation’s third-leading cause of death. The National Stroke Association estimates that the affliction will affect 795,000 Americans this year and kill 137,000.
Many strokes are caused by a blood clot that forms in a partially blocked artery in the neck and travels to the brain (thus the moniker “brain attack”). Doctors usually check for clogged arteries by using a stethoscope to listen for abnormal sounds in the carotid (neck) arteries. An ultrasound can confirm a blockage.
Patients with clogged carotid arteries have had limited choices for clearing the blockage and preventing a stroke. They could either take medication and make lifestyle changes to improve their cardiovascular health, or they could undergo surgery to open the arteries. Poor candidates for surgery are allowed under federal regulations to undergo stent placements to help reduce their risk of stroke.
The clinical study, dubbed Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST), was funded by the National Institute of Neurological Disorders and Stroke in Bethesda, Md., and Abbott Laboratories in Abbott Park, Ill. One of the largest randomized stroke prevention trials ever held, CREST took place at 117 locations throughout the United States and Canada. Results of the trial were released earlier this year at the 2010 International Stroke Conference in San Antonio, Texas.
The study compared carotid endarterectomy, a fairly common procedure to treat a narrowing of the carotid artery, with the study procedure, carotid artery stenting. During stenting, a catheter is used to deliver a stent into the carotid artery to expand the constricted area and capture any dislodged plaque.
“The CREST data suggest that a larger group of patients, especially younger patients, are good candidates for carotid stenting,” said Kenneth Rosenfield, M.D., FSCAI, an interventional cardiologist and section head for vascular medicine and intervention at Massachusetts General Hospital in Boston, Mass. “These results will enable patients to have more choices, including less-invasive therapy, for clearing their carotid artery. Physicians will also be able to provide better guidance to their patients as to benefits and risks for the various alternative treatments, based on an individual's health history; this should lead to improved patient outcomes.”
The study found that patient outcomes generally were equal between carotid stenting procedures and the more invasive surgery, regardless of gender or stroke history. Researchers, however, noticed a difference in that equality among different age groups. Patients aged 69 and younger, for instance, responded better to carotid stenting, while patients older than 70 seemed to have better results with carotid endarterectomies.
About half the study’s patients had never suffered any symptoms of a stroke, despite showing significant blockages in their carotid arteries. These patients, as well as those who had suffered previous mini-strokes, benefitted equally from either artery-opening procedure.
While carotid surgery can significantly reduce the risk of stroke and death (by about half in people with major blockages, industry data indicate), drug therapy—particularly statins—can be effective as well. A steady improvement in drug therapy since the last landmark study of carotid surgery in 1995 has led many doctors to advise asymptomatic patients against undergoing stent procedures and surgery altogether. As a result, the CREST study’s lead investigator is now planning to conduct a new trial comparing all three approaches.
Surgery traditionally has been the most common treatment for blocked carotid arteries, though stenting has become popular in recent years. Not all doctors, however, believe stents are safe. Three studies have questioned the safety of these devices, including one that was published on the same day the CREST results were announced.
European researchers found a higher rate of stroke, death or heart attacks among stent patients after four months compared with those who underwent a carotid endarterectomy, according to results published in the Lancet. However, doctors have said the European studies did not take into account some of the factors that can improve the performance of stents, such as standard drug therapy, higher training certification for doctors performing the procedure and the use of embolic protection, devices that are used to catch dislodged plaque during the stenting procedure. Experts warn that loose plaque eventually can cause a stroke.
Wire Manufacturer Expands Medical Device Subsidiary
New England Wire Technologies finally made it official.
Several years after announcing the creation of a subsidiary, the Lisbon, N.H.-based wire and cable provider held a ribbon-cutting ceremony to celebrate its “official” foray into the medical device industry. The ceremony was held in early March to mark a 13,000-square-foot expansion of New England Catheter Corp. in the company’s original building in Lisbon.
“We have seen many changes and challenges over the years and the complexity of our wire and cable products have increased to meet the needs of our customers,” said Richard Jesseman, marketing director for New England Wire Technologies.
Customer demand, in fact, helped convince executives at New England Wire to “open” a subsidiary that manufactures custom braid reinforced tubing, lined catheter shafts, and hybrid tubing. The popularity of minimally invasive procedures involving catheters (those tiny hollow tubes that either deliver or remove fluids to or from the body) has led to shorter hospital stays, significantly reduced recovery times and improved treatment options for patients.
About 35 state and local dignitaries attended the ribbon-cutting celebration for New England Catheter, according to an article in the Littleton Courier, a small, community-based newspaper in Littleton, N.H. One official who attended the ribbon-cutting ceremony called the event a “big confidence boost” for both Lisbon and Grafton County.
“It shows that even in the worst recession since the Great Depression, American companies can still compete with overseas competition and develop new markets that hire U.S. workers,” said Mark Scarano, executive director of the Grafton County Economic Development Council.
New England Catheter employs about 15 people.
Growing New Blood Vessels
Scientists are continuing to blur the lines between science fiction and reality.
Researchers on both U.S. coasts are studying ways to grow blood vessels that can be implanted in the body. Such a technological breakthrough would revolutionize organ transplantation and lead to a “biological bypass” (or non-invasive way) to treat coronary artery disease.
At Yale School of Medicine in New Haven, Conn., researchers experimented with the signaling pathways of cells to grow arteries. Past efforts targeted proteins that stimulate cell growth to create new arteries, but that method was unsuccessful. Michael Simons, M.D., chief of the Section of Cardiology at Yale School of Medicine, and a team of researchers studied mice and zebrafish to determine whether they could grow new arteries by switching on and off two cell signaling pathways known as ERK1/2 and P13K.
“We found that there is a cross-talk between the two signaling pathways. One half of the signaling pathway inhibits the other,” Simons told ScienceDaily.com. “When we inhibit this mechanism, we are able to grow arteries. Instead of using growth factors, we stopped the inhibitor mechanism by using a drug that targets a particular enzyme called P13-kinase inhibitor.”
Simons wants to test the finding in a human clinical trial to determine whether his team can grow arteries by inhibiting the same signaling pathway in the human body.
“It opens the possibility of developing a new class of medication to grow arteries,” he noted. “Successfully growing new arteries could provide a biological option for patients facing bypass surgery.”
Bypass surgery patients also may benefit from regenerative medicine research at Organovo Inc., a San Diego, Calif.-based company that claims to have developed technology to “print” artificial blood vessels for transplant. The vessels are printed on a 3-D medical printer that was built by Invetech, a design and contract manufacturing firm with offices in Australia and San Diego.
The 3-D printer includes a software interface that allows engineers to build a model of the tissue to be transplanted before the printer starts constructing an organ cell by cell by using automated, laser-calibrated print heads. The cells are laid down in precise positions in three dimensions, accurate to within 20 microns. The particles used to build these model organs are composed of stem cells, formed into tiny spheres and cylinders.
“Scientists and engineers can use the 3-D bio printers to enable placing cells of almost any type into a desired pattern in 3-D,” said Keith Murphy, Organovo’s CEO. “Researchers can place liver cells on a preformed scaffold, support kidney cells with a co-printed scaffold, or form adjacent layers of epithelial and stromal soft tissue that grow into a mature tooth. Ultimately the idea would be for surgeons to have tissue on demand for various uses, and the best way to do that is get a number of bio-printers into the hands of researchers and give them the ability to make three dimensional tissues on demand.”
The stem cells used for research purposes will come from life sciences firms, but when the 3-D printer is used for treatment, the stem cells will come from the patient (bone marrow, for example). Since the patient is using his or her own (adult) stem cells, the body is unlikely to reject the new transplant, Murphy said.
American College of Cardiology Has New President
Ralph Brindis, M.D., M.P.H., F.A.C.C., has been elected president of the American College of Cardiology (ACC).
Brindis’ election occurred during ACC’s annual meeting last month in Atlanta, Ga. Upon assuming leadership of the 37,000-member nonprofit medical society, Brindis discussed threats to the cardiology industry and ways the ACC can fight for itself, its members and patients.
“I am honored for the trust my colleagues have placed in me to lead the College at this important time,”
Brindis said. “It’s my hope that throughout the next year we can promote the patient-cardiovascular specialist relationship as the nation pursues healthcare reform while we further improve our delivery of high quality cardiovascular care through the strengthening of the ACC’s science-based appropriate use criteria and our cardiovascular data registries.”
Brindis claimed the patient-cardiovascular specialist relationship is under unprecedented stress due to various issues, including the lack of a long-term, fair approach to cost containment, cuts to Med-icare reimbursements, and Medicare’s use of the Physician Practice Information Survey to determine this year’s fee schedule. Brindis said these issues threatens both the profession and the nation’s health.
“The ACC must adapt to the changing environment,” he noted, “but not in a way that would be destructive to our mission in providing high-quality CV care and destructive to our patient-CV specialist relationship.”
Brindis discussed the college’s strategic priorities for 2010, which include focusing on patient value, providing tools for practice survival and transformation, and advancing quality tools and resources.
Biotech in Brief
Brazil’s government will spend $573 million it secured from BNDES, the country's national economic development bank, on infrastructure projects and research and development (R&D) efforts in the bioscience field. The funding, which will be spent over five years, mainly will focus on R&D efforts related to diagnostic reagents… Indiana has unveiled a $58 million venture capital fund to support the continued growth of the state's life sciences industry. The INext Fund is being organized through Indiana’s life sciences initiative, BioCrossroads, and includes investments from Eli Lilly and Company, the Indiana State Teachers Retirement Fund, Indiana University, Purdue University, the University of Notre Dame and the Fairbanks Foundation…Unilife Medical Solutions Ltd., a designer, developer and manufacturer of retractable syringes, is relocating most of its key operations from Australia to central Pennsylvania. The company is building a new facility in York County to support future anticipated demand for its syringes…United Kingdom-based Lab21 has acquired Selah Technologies, a manufacturer of nanotech-based diagnostic products. Lab21 executives hope the deal will help boost its position in the worldwide diagnostics market. The company also will expand its operations to the United States by setting up a laboratory in Greenville, S.C., that is expected to open by early next year…Tool and equipment maker Danaher Corp. has acquired laboratory equipment specialist Genetix Group PLC for approximately $82 million. Headquartered in the United Kingdom, Genetix designs and manufactures equipment and supplies for laboratory research, focusing specifically on imaging and image analysis used to develop pharmaceuticals, biotherapeutics and clinical diagnostics…The board of directors of the Massachusetts Life Sciences Center has awarded 28 life sciences companies a total of $25 million in tax incentives. The first-year life sciences tax incentive program is designed to create and keep jobs in Massachusetts, as well as address the costs associated with life science research and development. The 28 companies, chosen from a pool of 85 applicants, have agreed to create 918 jobs in the next year. As part of the program, the newly created jobs must be maintained for a minimum of five years…Presidents Bill Clinton and George W. Bush will participate in a moderated discussion at the 2010 BIO International Convention, slated for May 3-6 in Chicago, Ill. The two former presidents will discuss various issues related to foreign policy.