A second company earned U.S. regulatory approval in the embolic protection field last month, with Boston Scientific's (Natick, Massachusetts) FilterWire EX Embolic Protection System joining Medtronic's (Minneapolis, Minnesota) PercuSurge GuardWire Plus system, which was approved by the FDA in June 2001. Such devices are designed to prevent particles that may be dislodged during a stent or angioplasty procedure from creating blockages of their own, especially in the small vessels of the brain or lungs. Boston Scientific received 510(k) clearance to market the FilterWire EX Embolic Protection System to treat saphenous vein graft (SVG) disease and immediately launched the product in the U.S. The FilterWire EX system is the first filter-based system approved for SVG treatment in the U.S., in contrast to Medtronic's device, which temporarily occludes the vessel and uses vacuum pressure to retrieve the particles.

Boston Scientific was granted the CE mark in Europe in 2001 for the FilterWire EX system for use in peripheral, coronary and carotid vessels.

The FilterWire EX system is a low-profile embolic filter mounted on a guidewire that is designed to reduce complications during balloon angioplasty and stenting procedures in SVGs. It captures embolic material that becomes dislodged during cardiovascular interventions. The debris captured by the filter would otherwise travel into the microvasculature where it could potentially cause a heart attack. "Patients with degenerated saphenous vein grafts undergoing angioplasty and stenting are at very high risk for complications," said Gregg Stone, MD, of Lenox Hill Hospital (New York). "The availability of the FilterWire EX Embolic Protection System is a major advance in our ability to safely treat these patients."

Embolic protection has traditionally been addressed in two ways: pharmaceutically, which generally impacts blood clotting but does not address debris embolization, and with protection devices that actually capture debris. The Boston Scientific and Medtronic devices are initially indicated for use in saphenous vein grafts that have become occluded after coronary artery bypass graft surgery. However, it is believed that the ultimate market for these devices may be expanded significantly with additional indications for use in carotid artery stenting, acute myocardial infarction (AMI) and other peripheral vascular applications. Tom Fleming, vice president of marketing for embolic protection at Boston Scientific, said that SVG is an important introductory market for the company, but acknowledged that it has bigger plans for the system. "It's [SVG] an area that's got a big need, with MACE [major adverse cardiac events] rates running in the 20% range, so it has a need but it's not the only area we've got an interest in," Fleming told Cardiovascular Device Update. He said the company has an ongoing study for the use of the device in carotid arteries in conjunction with its Carotid Wallstent device and also is looking at the AMI area.

Boston Scientific also reported final results from its FIRE clinical trial, which studied the FilterWire EX system. The objective of the trial was to establish the safety and efficacy of the FilterWire EX system during balloon angioplasty or stenting procedures in the treatment of SVGs. The multi-center study compared the FilterWire EX product to the PercuSurge GuardWire Plus System in a non-inferiority (equivalence) trial that enrolled 651 patients at 55 U.S (332 in the FilterWire arm and 319 in the PercuSurge arm) sites and four sites in Canada. The cumulative MACE incidence at 30 days was 9.9% for patients receiving treatment with the FilterWire EX system vs. 11.6% for those receiving treatment with the GuardWire Plus System.

Elsewhere in the product pipeline:

Arrow International (Reading, Pennsylvania) reported the outcome of the first human implant of the CorAide continuous-flow ventricular assist system. The device was implanted as a bridge to transplant in a 65-year-old German male patient on May 8. The operation was performed without incident. However, after three days, the patient's plasma-free hemoglobin (damaged red blood cells) level was sufficiently above normal to warrant replacement of the CorAide with another bridge device pending the availability of a donor heart. The elevated plasma-free hemoglobin was unexpected based on extensive animal testing, and the company is evaluating to what extent the surgical procedure, the patient's blood chemistry or the device may have contributed to this condition. It said that in every other respect, the CorAide performed as expected. Arrow said it is reviewing all aspects of this initial human implant and considering what action may be necessary to limit red blood cell damage during future tests.

Biotronik (Lake Oswego, Oregon) reported the first five nationwide implants of the Cardiac Airbag ICD System. This new device is designed to address the demand for affordable patient care by combining targeted therapy with an e-commerce business model. The Cardiac Airbag was commercially released during the annual meeting of the North American Society of Pacing and Electrophysiology in Washington, after receiving approval from the FDA. At 39 cc and 73 grams, the device delivers up to 30 joules of energy and incorporates the latest technologies. The system requires only 10 parameters to be programmed during implantation and follow-up procedures. In addition to providing 24-hour support, Biotronik is offering comprehensive training to allow each medical center to independently care for Cardiac Airbag recipients. The Cardiac Airbag ICD provides essential lifesaving features for patients at risk of sudden cardiac death, including a programmable therapy zone that provides shock therapy for the critical treatment of ventricular fibrillation. A dedicated monitoring zone also is available to record ventricular tachycardias with a full 30 minutes of two-channel electrograms. The Cardiac Airbag features the company's Automatic Sensitivity Control, a beat-to-beat sensing algorithm. Rate-adaptive pacing and post-shock, high-output pacing also are standard in the Cardiac Airbag ICD.

CardiacAssist (Pittsburgh, Pennsylvania) received 510(k) clearance from the FDA for its Transseptal Cannula, part of the company's TandemHeart Percutaneous Transseptal Ventricular Assist (PTVA) System. Cardiologists and cardiac surgeons typically prescribe the TandemHeart System in critically ill heart failure and cardiogenic shock patients for short-term circulatory support. The FDA clearance now allows the company to market the complete minimally invasive TandemHeart PTVA System to physicians across the U.S. as a short-term circulatory support system. The Transseptal Cannula is the final component of the TandemHeart PTVA System to be cleared by the FDA. The TandemHeart PTVA System was previously awarded the CE mark for commercial sale in Europe in 2000. CardiacAssist continues to evaluate the TandemHeart PTVA System in the U.S. at various centers through a pivotal FDA clinical trial. That cardiogenic shock trial is investigating the hemodynamic support of the TandemHeart PTVA System compared to conventional intra-aortic balloon pump therapy.

Cardiac Science (Irvine, California) said the June 1 edition of the American Journal of Cardiology included a clinical study that demonstrates the high level of sensitivity and specificity of the company's Powerheart CRM fully-automatic bedside monitor defibrillator in detecting and providing therapy for life-threatening supraventricular tachycardia (SVT) arrhythmias, which often result in sudden cardiac arrest. The 98-patient study was performed at the Arizona Heart Institute's (Phoenix, Arizona) electrophysiology laboratory and was designed to determine how well the Powerheart device and its embedded proprietary Rhythmx software technology could discriminate between SVT and ventricular tachycardia and determine if life-saving defibrillation therapy was appropriate.

The Circulatory System Devices panel of the FDA voted unanimously last month that Cardima's (Fremont, California) Revelation Tx Microcatheter Ablation System for the treatment of atrial fibrillation (AF) was "not approvable." The panel reacted favorably to the catheter's safety and agreed that it was needed in cardiac catheter labs, but it was less receptive to the device's efficacy data. "Bluntly, we all agree that the data does not prove the device's effectiveness, and based on the pained looks of the panel that's the consensus," said Warren Laskey, MD, panel chair and chief of interventional cardiovascular medicine at National Naval Medical Center (Bethesda, Maryland). "While we are disappointed by this panel decision, we intend to immediately undertake the activities necessary raised during the panel discussion," said Cardima CEO Gabriel Vegh in a statement following the meeting.

CardioDynamics (San Diego, California) repor-ted the publication of an international clinical study demonstrating the significance of the company's ICG technology for pacemaker optimization in Pace, a peer-reviewed publication in the field of electrophysiology. The independent study, conducted by researchers at Queen Mary Hospital (Hong Kong), the University of Hong Kong and St. Jude Medical (Sylmar, California), demonstrated the utility of the company's ICG technology to determine cardiac output (amount of blood the heart pumps each minute) during pacemaker optimization compared to the echocardiography/Doppler (echo) method. Although pacemaker optimization can significantly improve a patient's cardiac output, the vast majority of patients with dual-chamber pacemakers are not optimized with echo because it is a time-consuming, expensive and operator-dependent method. The study's investigators concluded, "Previous studies have shown that optimization of the AV (atrioventricular) interval can contribute up to 40% of the cardiac output. Therefore, it is an important step to maximize the hemodynamic benefits of cardiac pacing, especially during cardiac resynchronization therapy for congestive heart failure." They added, "This study demonstrates the feasibility and ease of use of the impedance technique to determine cardiac output during left ventricular pacing with close correlation with Doppler echo."

In what the company believes is a potentially huge breakthrough, CardioGenesis (Foothill Ranch, California), a developer of angina-relieving transmyocardial revascularization (TMR) and percutaneous myocardial revascularization (PMR) products, said last month that its TMR procedure was performed thoracoscopically with robotic assistance at the Healthpark Medical Center (Fort Myers, Florida) of Lee Memorial Health Systems by Gary Allen, MD, attending cardiothoracic surgeon. The robotically assisted thoracoscopic TMR procedure was facilitated by the company's flexible fiberoptic delivery system and resulted in a less-invasive application of the laser system, which may give CardioGenesis a backup plan in the minimally invasive space if the PMR procedure does not win approval in the U.S. The normal method for accessing the heart for TMR is via a left-thoracotomy, which is an incision of several inches under the patients left breast. By contrast, Allen performed this TMR procedure through a series of small incisions, made possible by the use of robotic control of a thoracoscopic visualization system. CardioGenesis Chairman and CEO Michael Quinn said that cardiothoracic surgeons have demonstrated the technical viability of minimally invasive surgical approaches to myocardial revascularization, including a thoracoscopic approach, in IDE studies using the company's flexible fiberoptic technology. He noted that the new approach could have a huge impact on the TMR market. "Right now, sole therapy is only 5% of the total cadre of procedures done by either ourselves or PLC Systems [Franklin, Massachusetts]."

CardioTech International (Woburn, Massachusetts) reported the conclusion of an in vivo study using a microporous polyurethane-encapsulated coronary artery stent. This opens a potential market of $3 billion annually in the drug-eluting stent field, the company said. Eleven Yorkshire pigs were implanted for 30 days with a microporous stent using CardioTech's proprietary ChronoFlex polyurethane. The microporous encapsulation was achieved by using a proprietary electrostatic technique. At the conclusion of the experiment, the implant sites were evaluated for neointimal area, medial area and percent stenosis at the proximal, middle and distal edge locations. The ChronoFlex polymer showed no signs of causing inflammation, or intimal hyperplasia in the arterial walls.

Fluke Biomedical (Everett, Washington) introduced the new multi-parameter patient simulator, MPS450, a complete redesign of the Bio-Tek Lionheart 3 product. The MPS450 has many new features and functions, including a menu-driven interface that provides an intuitive method of navigating through the multitude of tests and functions, an extra port for future expansion into the next logical test parameter, 43 arrhythmias for improved testing of today's advanced arrhythmia detection systems, a greater range of amplitudes and rates and a larger display. The company said the MPS450 retains the best features of the Lionheart 3, including full parameter simulations (ECG, arrhythmia, respiration, invasive blood pressure, temperature and cardiac output) and adds fetal simulations and a platform for future simulation enhancements. It is the first true Fluke Biomedical product, combining the best technologies from its former brands, Bio-Tek Instruments and DNI Nevada.

Gish Biomedical (Rancho Santa Margarita, California), a wholly owned subsidiary of CardioTech International (Woburn, Massachusetts), has gained FDA clearance for its heparin coating to be used in conjunction with its line of heart-lung bypass products, and it thus opens a door for use of heparin coatings on many more CardioTech products, according to the company. The company estimated that the potential market for coated heart-lung bypass products alone could reach $200 million annually. The GBS (Gish Biocompatible Surfaces) Coating is a heparin-based, covalently bound biocompatible coating that will be used to cover the surfaces of Gish disposable products. Heparin coatings are known to inhibit blood coagulation, decrease the risk of systemic inflammatory response syndrome, reduce complement activation and platelet adhesion, reduce blood loss and hemolysis, provide stable anti-thrombotic activity and reduce thrombus formation, as well as decrease leukocyte (white blood cells) activation. Gish was acquired by CardioTech in March.

Guidant (Indianapolis, Indiana) said it has enrolled the first patient in its second clinical trial designed to evaluate carotid artery stenting as a minimally invasive alternative for patients who are at high risk for stroke and who are ineligible for current surgical options or at high surgical risk. The clinical trial, called Acculink for Revascularization of Carotids in High-Risk Patients (ARCHeR RX), is a prospective, non-randomized, multi-center, single-arm study that will enroll 145 patients in the U.S., Europe and South America. The first patient was treated in late May at the Baptist Heart and Vascular Institute (Knoxville, Tennessee). Nearly 25% of strokes are attributed to embolic events. ARCHeR RX is designed to show equivalence in the safety and performance of Guidant's Rapid Exchange (RX) versions of the Accunet and Acculink devices with the over-the-wire Accunet and Acculink devices. The company plans to offer both the RX and OTW versions of the system. Both versions of the system already are available in Europe.

Imagyn Medical Technologies (Irvine, California), a developer of internal bioelectrical impedance technology, last month received 510(k) clearance to market its ECOM endotracheal cardiac output monitor in the U.S. The approval permits use of the system in patients who are orally intubated for an expected duration of 24 hours or less. ECOM is designed to measure cardiac output through an endotracheal tube, which is used to keep a patient's airway clear during the administration of anesthesia. The ECOM tube is characterized by an array of small electrodes imbedded on the balloon cuff that anchors the tube in the trachea. Once the tube is placed in the patient's airway, the electrodes reside, said the company, "right around the corner from the ascending aorta, which is an ideal location from which to measure cardiac output." Using the principle of bioimpedance, the system's electrodes sense the changes in electrical current with the arterial blood pumped for the heart. A proprietary algorithm in the system's software converts these changes into cardiac output, which is displayed on a bedside monitor for the anesthesiologist and surgeon to read.

i-STAT (East Windsor, New Jersey) said a study showed that its hand-held, point-of-care test for diagnosing heart attacks is comparable to tests evaluated by central laboratory instruments. The i-STAT system cardiac troponin I test scans the blood for cardiac troponin I, a protein marker observed in those who suffer heart attacks. The company said the study results, presented at 6th National Congress of Chest Pain Centers in San Francisco, California, would be used to support a 510(k) submission it intends to file with the FDA later this spring. Separately, i-STAT reported its submission of a 510(k) pre-market notification with the FDA for the new 10-minute i-STAT System Cardiac Troponin I (cTnI) test. A portion of the data used to support this 510(k) submission had previously been presented at the San Francisco meeting. These results demonstrated that the accuracy, precision, and analytical sensitivity of this test were comparable to state of the art central laboratory instruments. This test will be performed at the patient's side using i-STAT's single-use, disposable cartridge technology, with the laboratory-grade sensitivity required to appropriately diagnose patients in the ER. The cTnI cartridge will mark expansion of the capabilities of the i-STAT System to immunoassays, a major addition to the electrolyte, blood gas, chemistry and coagulation capabilities already available on the system.

Medtronic (Minneapolis, Minnesota) reported the first uses of the EnPulse pacing system in several patients to begin a clinical evaluation of this new device for slow-beating hearts. The device is designed to continuously measure changes in the heart's upper and lower chamber threshold levels the minimum level of electricity that needs to be delivered to stimulate a heart beat and, as necessary, automatically adjust the amount of pacing output that is delivered to both chambers. The trial will evaluate the safety and ability of the EnPulse system to help physicians better manage pacing therapy and simplify follow-up care for patients. The beginning of the EnPulse clinical evaluation included system implants in 11 patients in mid-May. Physicians at about 25 medical institutions worldwide will be involved in the clinical evaluation of the EnPulse pacemakers during the next few months. Medtronic also said it is distributing a Health Insurance Portability and Accountabilty Act-ready version of the Medtronic Paceart System that incorporates several new features designed to empower clinics to protect the privacy of patient data. The Paceart System is an arrhythmia information management system that allows clinicians to efficiently organize historical data about a patient's heart rhythm and the performance of his or her implanted device, which can contribute to the ability for them to make well-informed decisions about patient care needs. New features include capabilities to guard against unauthorized access to patient data; the ability to tailor its use based on the responsibilities of individual clinic staff members; and track and audit changes made to patient data within the system. The system now can receive data from all commercially released arrhythmia devices from leading U.S. suppliers, increasing the speed and accuracy of data management during the follow-up session. The system now automatically detects and displays multiple events and device leads from within event recorder data transmissions received via telephone.

MIV Therapeutics (MIVT; Vancouver, British Columbia) said it has achieved a significant milestone by successfully passing an independent thrombogenicity animal trial of its proprietary hydroxyapatite (HAp) coating. Stainless steel and cobalt-chromium stents coated with MIVT's biocompatible HAp coating were implanted in the arteries of dogs. MIVT has developed two formulations of a HAp stent coating and protected these collaborative technologies with three patents.

Nuvelo (Sunnyvale, California) reported the start of dosing in a Phase II trial with its lead product candidate, alfimeprase, for the treatment of catheter occlusion. The multi-center, randomized, double-blind study will evaluate the safety and efficacy of alfimeprase for restoring function to occluded central venous catheters. The study will compare three doses of alfimeprase against the approved dose of t-PA (alteplase). The study will be conducted in about 100 patients across 20 centers in the U.S. Alfimeprase is a modified fibrolase that directly degrades fibrin when delivered through a catheter at the site of a blood clot.

Rheologics (Exton, Pennsylvania) said that its scanning blood viscometer, the Rheolog, has been selected for use in a clinical study on congestive heart failure (CHF) at Christiana Care Health Services (Wilmington, Delaware). The six-month study will focus on whole blood viscosity changes during recovery from acute heart failure. In particular, the relationship between measured blood viscosity and other diagnostic variables in patient recovery over the progress of two to five days will be evaluated. The intent of the research will be to better understand congestive heart failure and possible treatments for the condition. The Rheolog is the industry's first clinically practical device capable of generating a comprehensive rheologic profile at the patient point of care, which measures the biophysical properties of blood in an environment that mimics the human vascular system, the company said.

St. Jude Medical (St. Paul, Minnesota) reported enrollment of the first patients in its RHYTHM ICD V-V (left ventricle, right ventricle) optimization phase of the RHYTHM (Resynchronization Hemodynamic Treatment for Heart Failure Management) ICD study. Enrollment in this phase of the study will be completed using both control patients from the original study phase, as well as patients newly enrolled in the V-V phase of the RHYTHM ICD study. The study is evaluating the efficacy of the Epic HF ICD. The V-V optimization phase extends the study's protocol to include cardiac resynchronization therapy (biventricular pacing) with programmable V-V timing (programmable interventricular pacing delay). This option is only available in the V-V optimization phase. The device also can be programmed to pace either the left or right ventricle first. The initial phase of the RHYTHM ICD study protocol evaluates simultaneous biventricular pacing only.

William Wagner, MD, associate professor of surgery and bioengineering and deputy director of the University of Pittsburgh's (Pittsburgh, Pennsylvania) McGowan Institute for Regenerative Medicine, has developed an engineered tissue to treat heart defects. Wagner's flexible and biodegradable material uses a specialized polymer that is porous, with that porosity encouraging the infiltration and growth of cells. So far, only adult rats with defects have been treated with the material, dubbed a "cardiac patch." After four weeks, the patches and surrounding tissue were studied for evidence of inflammation, scarring and appropriate cell growth. The results have been encouraging, said Wagner, and the levels of repair and cell regeneration are satisfactory, as well as showing minimal signs of inflammation. "Future application of this material as a cellular scaffold in cardiovascular tissue engineering appears promising," he said.

Vitatron (Minneapolis, Minnesota) reported FDA approval of its Vitatron Ventricular Rate Stabilization (VRS), a software upgrade for patients who have an implanted Vitatron Selection AFm pacemaker system. VRS can help stabilize the rate of the heart's lower chambers (ventricles) during episodes of conducted atrial fibrillation (AF), which may reduce the symptoms of AF. It is the first-ever U.S. pacemaker therapy enhancement to be installed without surgery through a programmable software upgrade. VRS can be uploaded into the Selection AFm pacemaker simply by placing a programming device on the chest over the patient's pacemaker. During a recent clinical study in Europe and Canada to evaluate the safety and effectiveness of VRS, a majority of patients with sporadic episodes of conducted, symptomatic AF who received VRS therapy preferred to have VRS turned on.

Zargis Medical (Princeton, New Jersey) said it has submitted a 510(k) application to the FDA for clearance to market the Zargis Acoustic CardioScan system (ZACS). ZACS is based on a computer-aided analysis of heart sounds and is designed to aid physicians in identifying sounds that may be indicative of congenital and valvular heart disease. ZACS will initially be targeted toward primary care physicians for use in general medical examinations. The ZACS system is a portable unit consisting of an electronic stethoscope and a laptop computer, which runs the complex analytical software. The system processes and analyzes the patient's heart sounds, then provides easily interpretable results to the physician. The company said it hopes to receive FDA clearance of the ZACS system by the end of 2003.