Invasive Cardiology News II

Medtronic Advances Technology for Coronary Angioplasty with ‘Zipper’ Multi-Exchange Delivery Platform FDA Approves New Device That Facilitates Easy Exchange of Guidewires and Catheters; CE Mark for European Release Also Includes Stent Delivery Medtronic, Inc. has announced approval by the U.S. FDA and the European Union of the Stormer Balloon Dilatation Catheter with Zipper technology. The CE Mark approval applies to both catheter and stent delivery systems. The Medtronic Zipper Delivery Platform facilitates easy, quick exchange of wires and catheters during a coronary angioplasty or stenting procedure. Fundamental to the Zipper technology is a unique and proprietary Z-component seated in the channel of the catheter that delivers the guidewire. As the physician advances the catheter along the wire, the Z-component temporarily separates a small portion of the guidewire channel outside the body to feed the guidewire into the catheter. The separation automatically closes behind. The entire portion of the catheter inside the body is riding and surrounds the guidewire. Guidewires can be exchanged by using the Z-component to remove and introduce the wires while the catheter remains in place. The Zipper technology: Allows use of a short guidewire. Allows guidewires to be changed without removing the catheter from the patient’s body. Allows catheters of different sizes to be exchanged during the procedure without the long guidewire. Velocimed Announces Progress Toward Completion of a CE Mark Clinical Study of the Proxis Embolic Protection System Velocimed Incorporated has made progress toward completion of a CE mark clinical study in Europe of the Proxis Embolic Protection System, the first proximal embolic protection device designed for coronary applications. 15 of the 30 patients required for the CE mark trial have been enrolled. The vessels treated have included native and bypass graft coronary vessels. Velocimed started the trial August 12, 2002 at three hospitals in Germany. Velocimed has already met the EN 46001 and ISO 9001 requirements for the CE mark and will begin sales of the device in Europe upon successful completion of the CE mark clinical study. Catheter-based interventions in coronary blood vessels can be associated with a risk of a major adverse clinical event (MACE) (predominately myocardial infarction) or reduced blood flow to the vessels downstream of the treatment site. A recent study (SAFER Trial) suggests that embolization of atherosclerotic debris from the treatment site is an important determinant of major adverse clinical events, and that embolic protection devices play an important role in preventing such complications. The SAFER Trial in fact showed that distal occlusion embolic protection devices provided a 42% relative reduction (16.5% to 9.6%) in 30 day MACE when compared to no protection. Currently, physicians have the choice between distal occlusion balloon and distal filter wire technologies to protect patients from embolic events. These two distal embolic protection devices are either approved for clinical use or are being studied in clinical trials. However, these approaches are difficult to use and may not completely protect the patient from embolic events in certain anatomical situations. Additionally, since they are distal protection devices, they must initially cross the blockage without protection. The Proxis Embolic Protection System provides proximal protection allowing us to do cases we could not have done with distal embolic protection devices, said Prof. Horst Sievert of Cardiovascular Center Bethanien in Frankfurt, Germany. To date (September 16), the results have shown a 0% in-hospital MACE rate on the first 15 patients. This device is especially helpful in those lesions which are too distal to place a filter or distal occlusion balloon. It has the ability to capture small particles with a diameter of less than 100 micron. It is easier to introduce and we do not have to worry about retrieval. The Proxis Embolic Protection System is a proximal protection device that provides complete embolic protection from beginning to end of the procedure. Since the device is deployed upstream of the blockage (proximal) there is never a need to cross the blockage without first protecting the vessel. The Proxis device removes the embolic debris from the vessel by first stagnating blood flow, which suspends any embolic debris released and then removing it from the blood vessel by reversing flow in the vessel and capturing the embolic debris in a simple 20 cc syringe. Heart Attack Survival Less Likely if Kidneys Ailing Older people are less likely to survive a heart attack if they have even mild or moderate kidney disease, researchers report. Although severe kidney damage has long been known to decrease heart attack survival, the new findings suggest that other patients are at risk too and should receive special attention after a heart attack. The researchers also found that heart attack patients with moderate kidney disease were less likely than patients with healthy kidneys to get just about every treatment shown to improve survival after a heart attack including aspirin, beta-blockers, clot-busting drugs and angioplasty. In the study, Dr. Michael G. Shilpak of the Veterans Affairs Medical Center in San Francisco, California and colleagues evaluated the medical records of 130,099 men and women over the age of 65 who were hospitalized for a heart attack in the US between 1994 and 1995. Patients either had healthy kidneys or mild or moderate kidney disease. Death rates at 1 year were 66% for patients with moderate kidney disease, 46% for those with mild kidney disease and 24% for those with no kidney disease, according to the report. The elevated mortality risk continued until 6 months after the heart attack. Patients with healthy kidneys were more likely than those with kidney disease to receive many treatments, including aspirin, clot-busting drugs and certain procedures compared to either patients with moderate of mild kidney disease. Under-treatment of these patients with proven medical therapies could contribute to their excess mortality, Shilpak and colleagues note. Interventions such as clinical practice guidelines should address the quality of care for this high-risk subgroup of patients with (heart attack). Angioplasty Complication Fell Ten-Fold Since 1992 The risk of complications resulting from angioplasty has dropped dramatically from 10 years ago, according to a new report from the Cleveland Clinic Foundation in Ohio. During that time period, the likelihood of angioplasty patients at the institution requiring an emergency bypass decreased ten-fold. These improvements most likely stem from the use of better equipment and medications during angioplasty relative to 10 years ago, and from physicians growing more skilled at the technique, according to study author Dr. Patrick L. Whitlow. We still fail, he said. But it’s only one tenth the amount it used to be. During the study, Whitlow and his team reviewed records from 18,593 angioplasties performed at the Cleveland Clinic Foundation between 1992 and 2000. They found that only 113 patients required emergency bypass surgery after the procedure, and the rate of bypasses decreased from 1.5% of angioplasty procedures in 1992 to 0.14% in 2000. This translates to a ten-fold decrease in the need for bypass surgery during the study period. Fifteen percent of patients who underwent bypass surgery died in the hospital, while 12% experienced heart attack and 5% suffered a stroke. Whitlow explained much of the reduction in complications is likely due to improvements in the materials used during angioplasty, such as metal stents to prop open cleared arteries and anti-clotting drugs administered to the patient during surgery. Angioplasty was introduced in 1977, Whitlow added, so additional experience with the procedure has likely enabled surgeons to improve their techniques. Further refinements in surgical equipment and medications used during the procedure may reduce the rate of complications even more, he predicted. Interim Results of the ICE Cryotherapy Restenosis Trial Dr. Jean-Francois Tanguay of the Montreal Heart Institute presented interim acute and six-month follow-up results from the 15-patient Intraluminal Cryo Energy (ICE) Trial at the 14th Annual Transcatheter Cardiovascular Therapeutics Scientific Symposium (TCT) in Washington, D.C. The ICE trial was designed to assess the safety and feasibility of cryotherapy in peripheral arteries, and represents the first clinical use of CryoCath Technologies’ catheter cryotherapy system to treat patients with vascular occlusive (atherosclerotic) disease. The results from this initial study demonstrate the safety and feasibility of applying cryotherapy within the vascular system, said Dr. Tanguay. Although the study was not designed to determine efficacy, I am encouraged by the fact that most of the cryotreated patients exhibited clinical improvement at six months follow-up, and look forward to further clinical studies building upon what we’ve learned in the ICE Trial. Dr. Tanguay was the first physician to use cryotherapy to treat focal atherosclerotic disease in the superficial femoral artery with cryotherapy following percutaneous balloon angioplasty (PTA). In animal models, CryoCath has demonstrated that vessels treated with cryotherapy have larger luminal areas than corresponding arteries after balloon dilatation alone. The ICE trial was conducted at the Montreal Heart Institute, with Dr. Tanguay as the principal investigator, and at St. Michael’s Hospital in Toronto, under the direction of Dr. Bradley Strauss. Successful administration of cryotherapy was achieved using an early 7F design of the CryoCath CryoStent catheter in 11 of the 15 cases, with no acute or long-term complications attributed to cryotherapy, thereby demonstrating safety and clinical feasibility. Assessment of those cryotreated patients who have reached the six-month follow-up period indicate that 9 of 11 patients enjoy symptomatic improvement, with 8 of 9 patients having normal pedal artery pulses at follow-up. Although angiographic follow-up data have not yet been obtained on all patients, the available data suggest a significant reduction in luminal area (restenosis) in about half of the patients treated. CryoCath is currently in discussions with key investigators and potential development partners to design a protocol for further clinical studies. Since initiation of the ICE trial in 2001, preclinical and cryobiology data have been generated that better define the optimal cryotreatment dose. Future trials are planned with a dramatically improved cryotherapy system and at a precise cryotreatment dose that will optimize the clinical efficacy of cryotherapy for vascular disease. AVI Announces Positive Interim Results of Phase II Antisense Trial For Cardiovascular Restenosis AVI BioPharma, Inc., announced positive interim results of a Phase II clinical trial measuring the safety and efficacy of its antisense compound, Resten-NG, when delivered via catheter during balloon angioplasty procedures. The trial was designed to assess the safety and efficacy of Resten-NG in preventing coronary artery restenosis after angioplasty and stent placement for the treatment of atherosclerotic lesions. Resten-NG targets and blocks c-myc, a regulatory gene that is the key factor in the cascade of effects that lead to restenosis in many angioplasty patients. Data were presented for enrolled patients who have completed their six-month follow-up, including angiography and intravascular ultrasound (IVUS), to evaluate the restenosis level in patients in three study groups: a control group that received no drug treatment and two groups that received the antisense drug. The dose ranges for the antisense groups were determined from preclinical studies to be a sub-therapeutic dose (3 mg) and a therapeutic dose (10 mg). Patients who received 10 mg of Resten-NG had an 11 percent restenosis rate. Patients in the control group and those who received the sub-therapeutic dose (3 mg) of Resten-NG averaged approximately a 50 percent restenosis rate, which was expected in these high risk study patients. The patients who received the therapeutic dose (10 mg) of Resten-NG therefore experienced approximately an 80 percent reduction in the rate of restenosis. Patrick L. Iversen, PhD, senior vice president of research and development for AVI, said, Although these are interim results involving a small number of patients, the reduction in restenosis levels in antisense-treated patients compared to the control groups is substantial. Safety was evaluated by observation of adverse clinical events, particularly major adverse cardiac events (MACE) such as heart attack and the need for blood vessel or target lesion re-vascularization. Interim results indicate that Resten-NG is safe. No serious adverse events related to the drug have been observed. By blocking the c-myc gene, we've reduced the incidence of restenosis in patients predisposed to the disease, a crucial step in the development of Resten-NG, said Denis R. Burger, PhD, CEO of AVI. These preliminary results support our contention that AVI’s third-generation antisense compounds function as predicted by extensive pre-clinical studies and are clinically relevant. AVI has now demonstrated the effectiveness of its antisense compounds in human clinical trials against two gene targets, c-myc, as implicated in restenosis and other proliferative cell disorders, and cytochrome P450, a liver enzyme responsible for the metabolic breakdown of most FDA-approved pharmaceuticals. AVI is currently evaluating optimal delivery systems for Resten-NG in different therapeutic applications. Extensive preclinical testing has shown positive results in four different species and three different methods of delivery (drug-eluting stents, catheter delivery and targeted systemic delivery). Medtronic Inc. holds the rights for delivery of Resten-NG via medical devices (stents, catheters, etc.) for cardiovascular disease. AVI plans to initiate a human Phase II study using Resten-NG with its targeted systemic delivery technology in 2003. Pain Control Falls Short, Doctors Admit in Survey Nearly half of America’s physicians admit they do a poor job of controlling patients’ pain, especially for the terminally ill. Fear of litigation, disciplinary action, and criminal prosecution often stops them from following their own best clinical judgment. In fact, 1 in 4 doctors say such fears are the main reason they don’t adequately treat pain. Highlights of the survey include: Abortion and cloning 69% of doctors say abortion should remain legal. Yet nearly half say that partial-birth abortions should be illegal; only 27% favor them, and 28% aren’t sure. 72% favor parental notification laws when minors seek abortion. 21% of doctors say cloning of humans should be allowed; 84% support cloning to produce stem cells for medical research. End-of-life care Half of all surveyed doctors support physician-assisted suicide. But only 6% say they've personally helped a terminally ill patient end his life. Patient relations dilemmas 13% of doctors have intentionally withheld information from patients for their own good. 28% have revealed confidential information about a patient if his condition or behavior could adversely affect others. Two-thirds regularly practice defensive medicine, such as ordering unnecessary tests to protect themselves from malpractice suits. Managed care controversies 1 in 5 doctors have exaggerated a patient’s diagnosis in order to secure needed care from a health insurer. 1 in 4 have followed treatment guidelines promoted by insurers, hospitals, and others, even when they believed it wasn't in their patients’ best interests. Survey results were based on responses from more than 750 physicians in family and general practice, internal medicine, cardiology, ob/gyn, pediatrics, and other specialties, and full results are available at: www.memag.com Abbott Reintroduces Abbokinase (Urokinase) Abbott Laboratories has received approval from the U.S. Food and Drug Administration to reintroduce its clot-busting drug Abbokinase, which has been off the market for nearly four years due to safety questions. Abbokinase, known chemically as urokinase, is one of many drugs used to dissolve blood clots. It is made from kidney cells taken from newborns who have died and was used to treat an estimated 4 million patients from 1978-98. FDA inspectors halted shipments of Abbokinase in November 1998 after uncovering significant deviations from manufacturing rules that ensure drugs’ purity and safety. The agency said the kidney cells were taken from foreign newborns at high risk of carrying infectious diseases, yet Abbott didn't adequately test for infection and the cells were handled in a way that could have allowed contamination. Abbott has since upgraded its manufacturing facility and added controls throughout the production process to meet federal inspectors’ standards. Rate of Hospital Errors in Prescribing Meds Up More than Half of the Errors in Study Involve Cardiovascular Drugs Prescribers sometimes make mistakes when noting the physical form a prescription medication should take, such as a tablet, liquid or cream. However, these types of errors, known as dosage form errors, occur relatively often for hospitalized patients, and the rate at which they take place appears to have increased during the past 5 years, according to one U.S. researcher. Based on a review of dosage form errors at one hospital during that 5-year period, Dr. Timothy S. Lesar of the Albany Medical Center in Albany, New York, found that the rate of these errors increased from slightly higher than 0.6 for each 100 patients in 1996 to 1.3 per 100 patients in 2000. The findings are based on a review of all prescription errors stemming from mistakes in how the medication should be given to patients. The errors occurred at one 631 bed hospital in New York State between January 1, 1996 and December 31, 2000. Errors were considered to be orders that both the pharmacist and original prescriber believe contain an error that needs correcting. During the study period, a total of 1,115 errors involving dosage form took place, 52 of which were considered to be potentially fatal or have serious effects. The most common types of errors involved those in which the prescriber did not specify that the drug needed to be given to the patient in a controlled release form. Three of the instances of medication order errors, if not corrected, were considered to be potentially fatal or severe, while another 49 errors were classified as serious, Lesar reports. More than half of the errors involved cardiovascular drugs. Court Refuses to Stay Permanent Injunction in Paclitaxel-Coated Stent Dispute At a hearing in Chicago, the U.S. District Court for the Northern District of Illinois denied Cook, Inc.’s request for a stay of the permanent injunction issued last week in the dispute between Boston Scientific and Cook over Cook’s agreements with Guidant Corporation relating to the development and distribution of paclitaxel-coated stents. The Court ruled that the permanent injunction remains in place. The Court enjoined activities under the August 16, 2001 agreements between Cook and Guidant and enjoined Cook from distributing paclitaxel-coated stents through another party in a manner inconsistent with Cook’s and Boston Scientific’s co-exclusive license agreement with Angiotech Pharmaceuticals, Inc. In addition, the Court prohibited any commercial use of Guidant clinical data generated in connection with the Cook agreements, including obtaining regulatory approval to sell paclitaxel-coated stents in the United States or elsewhere. Researchers Find a Marker for Blood Clotting in Patients Who Suffer Cardiac Arrest Outside the Hospital Researchers in the department of emergency medicine at the University of Pittsburgh School of Medicine tried to determine the extent to which increased blood clotting occurs in patients who suffer cardiac arrest outside the hospital. Using blood samples collected from 28 patients, the researchers found that all but one patient showed evidence of clot formation within the veins and that clotting increased the longer the patient was in cardiac arrest. The researchers conducted their study by collaborating with municipal paramedics who were called to the scene of cardiac arrest. Blood samples were taken from those 28 patients who were between 30 and 80 years of age (with a mean age of 55). Seventy-five percent of the patients were male. It is worth noting that the one patient with no sign of clotting went into cardiac arrest in the presence of paramedics and was immediately resuscitated with an external defibrillator. The patient responded quickly with no impaired mental or neurological complications, explained one researcher. The researchers also determined from the blood tests that the longer a patient was in cardiac arrest, the more the patient's blood clotted.

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