Privately held Concentric Medical (Mountain View, California) received clearance from the FDA in mid-August to market the Merci Retriever, the first medical device cleared by that agency to remove blood clots from the brain in patients experiencing an ischemic stroke. The move by the FDA came a little less than six months after the agency's Neurological Devices Panel declined to take a formal vote on the system based on what it said was an absence of randomized control data and a bothersome mortality rate. While the panel did not take a formal vote at that late-February meeting, most members agreed that the company's clinical trial demonstrated efficacy on the revascularization endpoint and thus has potential. However, panel members were troubled by the 38% death rate in the firm's single-arm, 114-patient trial.

Of the 700,000 annual strokes in the U.S., about 83% (or 581,000) are ischemic. The Merci Retriever is a novel therapy that removes clots, restores blood flow and offers hope for ischemic stroke patients with no other options. The FDA granted clearance after a review of patient data obtained in a clinical study at 25 medical centers in the U.S. The Mechanical Embolus Removal in Cerebral Ischemia (MERCI) trial ultimately evaluated the device in 141 patients who were ineligible for the "clot-busting" drug tissue plasminogen activator, or tPA, which can only be used within three hours of stroke onset. Physicians participating in the MERCI study navigated the Merci Retriever into the brain using standard catheterization techniques, introducing the device into an artery in the groin area, then leading to the brain. Upon reaching the targeted area, the Merci Retriever is designed to restore blood flow by engaging, capturing and removing the blood clot.

The Merci Retriever is made of a nitinol wire with a helical-shaped tip. The helix is covered with a platinum coil for radiopacity, and the nitinol core wire is coated with a hydrophilic coating, ending proximal to the helical-shaped tip. The tip of the retriever has five loops, which are designed to capture thrombus from the neurovasculature and foreign bodies from the neurovasculature, peripheral vascular and coronary vascular systems. For both foreign body retrieval and thrombus removal, a microcatheter is positioned beyond the obstruction and the retriever is deployed. The microcatheter and retriever are pulled back to engage the foreign body or thrombus. All are then withdrawn from the body.

Gary Curtis, president and CEO of Concentric, explained how the company was able to gain a clearance from the FDA despite the lack of a panel vote. "We had to supply more data to the [FDA] staff, one of the complete data set," he told Cardiovascular Device Update. Curtis said that when the company first presented the data from the MERCI study at the panel meeting, it had supplied information on 114 patients. "In our response to the panel questions, we had 141 patients in the final study that we closed out with all the data forms and then had those analyzed." He said that this enhanced data under statistical review "provided comfort to the FDA staff that the panel questions were answered."

Clearance under the new indication is a boon to stroke patients because clinical trials demonstrate that in certain patients the device can reverse damage caused by a stroke. The retriever extends the window of treatment to eight hours, compared to the three-hour window typically afforded by tPA therapy used to dissolve blood clots. "FDA clearance of the Merci Retriever heralds a new era in stroke management," said Wade Smith, MD, PhD, national principal investigator for the MERCI Study and associate professor of neurology at the University of California, San Francisco. "This is a very exciting result for all of our patients and for stroke research. We experienced some remarkable outcomes during the trial and look forward to having this available for patients experiencing devastating strokes."

Curtis said, "Our goal has been to develop a straightforward technology that will change how stroke is treated around the world. By working with stroke centers to increase public awareness of the Merci Retriever and stroke symptoms, we expect to greatly improve stroke management."

He said Concentric already has sold product to 35 of the 75 hospitals it has targeted in its sales plan and has hired the sales force it thinks it will need for the first year. On the reimbursement front, he said the company would have to do a long-term outcomes study prior to applying to the Centers for Medicare & Medicaid Services (CMS; Baltimore, Maryland) for a specific coding. However, he noted that a patient admitted to the hospital with stroke is automatically coded DRG 1, "so there is ample resource to a hospital that if they can shorten the patient's hospital stay, there's more than enough incentive for them to use the device."

Elsewhere in the product pipeline:

Abbott Laboratories (Abbott Park, Illinois) has secured 510(k) marketing clearance for a Troponin-I test for use on its newest platform, the Architect i2000 Immunoassay System and Architect ci8200 Immunochemistry System. The test was introduced in markets outside the U.S. beginning in April. "The Architect platform is our newest platform, and this is our first venture into the cardiac assays on that platform," said Carl Trippiedi, senior product manager in global marketing, noting that cardiac is one of the main disease state markers that its hospital laboratory customers are looking for. In addition, he told CDU, "We have a strategy to be, and are striving to be, a leader in cardiac diagnostics." Trippiedi described the test as an "aid in the diagnosis of heart attack that goes along with other parameters such as EKG [and] medical history presentation."

AngioScore (Alameda, California) reported the receipt of FDA approval to begin the U.S. clinical trial for its flagship AngioSculpt scoring catheter and the initiation of patient enrollment in the trial. The multi-center trial is a prospective clinical study of the safety and efficacy of the AngioSculpt in 200 patients undergoing angioplasty to treat coronary artery disease. The study examines acute outcomes when the AngioSculpt scoring catheter is used for the treatment of a hemodynamically significant coronary artery stenosis for the purpose of improving myocardial perfusion. Designed for use on a routine basis in most predilatation cases, the AngioSculpt is comprised of an angioplasty balloon surrounded by a system of nitinol struts that score arterial lesions as the balloon expands to open the target artery during angioplasty.

Bioheart (Weston, Florida) said it has entered into an agreement with the Powell Gene Therapy Center at the University of Florida (Gainesville, Florida) to develop a second-generation stem cell recruiting myoblast technology that includes controlled release of angiogenic growth factors for improving blood supply. Bioheart is moving forward with additional comparative studies in animals and plans to be ready to submit an investigational new drug application to the FDA by the first quarter of next year, and the partners said they hope to enter begin Phase II trials next year. The technology is targeted at recovering scarred heart tissue damaged from a heart attack.

CardioGenesis (Foothill Ranch, California), developer of surgical products and accessories used in angina- relieving transmyocardial revascularization (TMR) and percutaneous myocardial revascularization (PMR) procedures, apparently will get another chance to make its case for a PMR approval in the U.S., although it will have to conduct another trial to make that a reality. The company reported last month that it and the FDA had agreed on the steps needed to design and initiate a new clinical trial to confirm the safety and efficacy of the beleaguered PMR. Chairman and CEO Michael Quinn said an early-August meeting was a "significant step forward" with the FDA in the company's efforts to gain clearance of the PMR procedure. PMR is a less invasive, catheter-based version of the FDA-approved surgical TMR system, which is designed to trigger the mechanisms of angiogenesis, or the creation of new blood vessels in the heart to relieve the often-crippling chest pain called angina via the use of a Holmium:YAG laser. The PMR system has been under evaluation in pivotal human clinical trials since 1997. The current PMA application was filed in December 1999 and amended in July 2002 to address concerns raised during an advisory panel meeting. Late last year, the FDA's Office of Device Evaluation determined that there was not sufficient information to demonstrate reasonable assurance of PMR's safety and effectiveness. The company reported in March that the FDA was "unable to reach a favorable outcome" for its supplemental premarket approval application for PMR following a meeting held that month with the Center for Devices and Radiological Health. Shortly after that session, the company said it would seek a cooperative pathway with the FDA. At that time, Quinn said he would have a meeting with the agency and attempt to come up with a "reasonable" and "attainable" course of action that will allow CardioGenesis to finally reach the finish line for the PMR therapy, which already is being used in Europe.

Edwards Lifesciences (Irvine, California) reported the successful treatment of the first patient in its RESILIENT (Randomized Study Comparing the Edwards Self-ExpandIng LifeStent vs. Angioplasty-alone In LEsions INvolving The superficial femoral artery or proximal popliteal artery) clinical investigation using the LifeStent NT Self-Expanding Stent system to treat patients with peripheral vascular disease. The LifeStent is a percutaneously delivered flexible mesh tube that expands when deployed to prop open a diseased vessel. The RESILIENT study differs from other superficial femoral artery (SFA) investigations, Edwards said, because it is intended to demonstrate superiority, not equivalence, of the LifeStent NT Self-Expanding Stent system over angioplasty in treating blockages in the SFA and popliteal artery. The company also reported the limited launch of the first sizes of its Edwards LifeStent NT Self-Expanding Stent system for use in treating biliary disease, with additional stent sizes to be introduced throughout 3Q04.

Epix Medical (Cambridge, Massachusetts) said it has initiated its first human clinical trial of EP-2104R, an injectable magnetic resonance imaging (MRI) contrast agent that targets blood clots, or thrombi, in the body. EP-2104R binds selectively to fibrin, an important component of thrombus, and is designed to provide a bright MR image to allow the detection of small clots in arteries and veins, many of which may be undetectable with currently available imaging methods. The trial will be conducted in the U.S. under a FDA investigational new drug application. Epix is collaborating with Schering AG (Berlin) in the development of EP-2104R.

Kensey Nash (Exton, Pennsylvania) has submitted an application for 510(k) clearance for its TriActiv System to the FDA. The TriActiv, formerly called the Aegis Vortex System, is a protection system designed to prevent material or debris, dislodged during stent procedures, from embolizing downstream and causing adverse coronary events such as a heart attack. This is accomplished with three integrated system features: an embolic protection balloon, and a combined active flush and extraction system to remove the problematic debris from the target vessel. Kensey Nash estimated the current market for these types of embolic protection systems at $100 million worldwide, and expected to grow substantially over the next several years as next-generation products are developed and indications are expanded. The application for 510(k) clearance contained data from the company's PRIDE (PRotection during saphenous vein graft Intervention to prevent Distal Embolization) trial which compared the TriActiv device against other approved embolic protection systems for the treatment of saphenous vein graft disease.

Medtronic (Minneapolis) reported FDA approval of the Attain 4194 Bipolar over-the-wire left-heart lead for use with cardiac resynchronization systems. This new steroid-eluting lead has an angled shape and can be inserted using either a guidewire or a stylet delivery method, giving physicians an extra option to successfully maneuver and position the lead in a variety of difficult venous anatomies. The Attain 4194 lead is designed for use with the InSync family of cardiac resynchronization therapy pacemaker and defibrillator systems, and expands Medtronic's left-heart lead family to include a 6.2 Fr lead body for improved stability in larger vein sizes, with lengths of 78 cm and 88 cm. The Attain 4194 lead has a proprietary silicone tip seal that reduces the potential for blood flow into the body of the lead, helping maintain proper pacing stimulation after the implant.

Medtronic Vascular (Santa Rosa, California) reported receiving approval from the Japanese Ministry of Health, Labor and Welfare to market the Driver Coronary Stent System in Japan. The Driver stent also received reimbursement coverage and is immediately available in Japan in diameters of 3.0 mm, 3.5 mm and 4.0 mm and in lengths of 9 mm, 12 mm, 15 mm, 18 mm, 24 mm and 30 mm. The cobalt-based alloy stent incorporates thinner struts, a low profile and advanced alloy to create a clinically proven, effective stent therapy option for patients, the company said. The Driver will be the first cobalt-alloy stent available in Japan.

Orqis Medical (Lake Forest, California) received FDA conditional approval to conduct a clinical trial to prove the safety and efficacy of its Cancion Cardiac Recovery System (CRS), designed to create a "rest to recovery" environment for acutely decompensated heart failure patients. The company will be pitting its device against current medical therapy, which for most chronic congestive heart failure (CHF) patients means long lengths of hospitalization and a regiment of drugs. "The goal of the trial is that Cancion treatment will be an effective therapy for these patients who are not responding well to the current medical management that are admitted [to the hospital] with acutely decompensated heart failure," said Ken Charhut, president and CEO of Orqis. Acutely decompensated heart failure represents 1 million primary and 2.5 million secondary hospital admissions annually. CHF patients suffering an acute episode "have fluid backing up into their lungs and have severe shortness of breath, and that's what generally brings them into the hospital," he said. Orqis Medical's device would be used to treat that acute condition to send patients, deemed non-responsive to current medical therapy, home from the hospital. The extracorporeal, minimally invasive Cancion CRS system consists of two arterial access cannulas, a pump and motor, and a control system. Increasing blood velocity down the thoracic aorta, it provides a circulatory boost while unloading the patient's heart. The therapy is applied via routine percutaneous catheterization, making it available to a wider population of CHF patients.

St. Jude Medical (St. Paul, Minnesota) reported FDA approval and first implants of the Frontier II biventricular (BiV) stimulation device. The device is part of an easy-to-implant system that maintains synchrony of the left and right ventricles in patients with atrial fibrillation and NYHA Class II or III heart failure who undergo atrioventricular (AV) nodal ablation. The Frontier II device and the previously released Frontier device are the only devices approved by the FDA for the application of biventricular pacing in a post-AV nodal ablation patient population. The U.S. version of the Frontier II device includes independently programmable right ventricle and left ventricle amplitudes and pulse widths to meet the individual energy requirements of each chamber of the heart and maintain capture, and negative AV/PV Hysteresis and DDT/R Modes Trigger designed to ensure BiV pacing. The first implant was performed in the U.S. at the University of Virginia Health System (Charlottesville, Virginia) and the first European implant at Philipps-University Marburg (Marburg, Germany).

Thoratec (Pleasanton, California) said that a notice filed in the Federal Register by the Centers for Medicare & Medicaid Services last month will result in increased reimbursement for the use of ventricular assist devices (VADs) and should impact physician uptake of its VAD systems. The notice indicated that for the fiscal year beginning Oct. 1, all VADs implanted for destination therapy (DT) will be reimbursed under DRG (diagnosis-related group) 103, which currently covers heart transplantation procedures. This is the finalization of a proposed rule from CMS, first reported in May. With the decision, reimbursement for the destination therapy indication will increase by about 30%, with the average Medicare payment to CMS-recognized destination therapy facilities increasing to about $125,000 to $130,000. Currently, 69 centers are recognized by CMS for destination therapy reimbursement. At this point, destination therapy is reimbursed under DRG 525, which covers the implantation of heart-assist devices and only covers about $90,000 to $96,000 of the roughly $140,000 to $145,000 price tag for implanting the device. Thoratec's HeartMate XVE LVAS (left ventricular assist system) is the only FDA-approved device for DT, or the permanent support of end-stage heart failure patients who are not eligible for heart transplantation. The company received that approval in November 2002 for its HeartMate VE, with the XVE device garnering a clearance via a PMA supplement in April 2003. "This is another important step in offering new therapeutic options for people with end-stage heart failure," said Keith Grossman, president and CEO of Thoratec. "As the second reimbursement increase in about a year, we believe this further reinforces CMS' recognition of the value of this therapy."

Ventracor (Sydney, Australia) reported the eighth implant of the VentrAssist "artificial heart" as part of a pilot trial conducted at The Alfred Hospital (Melbourne, Australia). Chief medical investigators Professor Don Esmore and Professor David Kaye said the patient was in a serious but stable condition after an eight-hour operation. The aim of the pilot trial at the hospital is to evaluate the safety of the VentrAssist in patients who are gravely ill from congestive heart failure, are no longer responding to optimal medical therapy and had no other options available to them. Ventracor's VentrAssist left ventricular assist system is designed as a permanent alternative to a heart transplant for patients suffering end-stage heart failure.

Viasys Healthcare (Conshohocken, Pennsylvania) reported the introduction of the VMAX Encore system for pulmonary function, cardiopulmonary stress and metabolic assessment testing. Marketed through Viasys Respiratory Technologies, the VMAX Encore system combines what Viasys said are unparalleled data acquisition capabilities, workflow efficiencies and seamless data flow to the patient electronic health record. The product also offers Viasys' Impulse Oscillometry, which allows for effort-independent testing to accommodate the most compromised patients and provides the clinician with both central and peripheral airway resistance measurements.

WorldHeart (Ottawa, Ontario) said the FDA has approved its premarket approval supplement application for a revision to the labeling of the Novacor LVAS (left ventricular assist system) to reflect the current device reliability data available to patients and physicians. Notable in the revised labeling is the demonstrated performance longevity of the Novacor LVAS, which encompasses implant duration from zero to more than 36 months. The revised labeling, which is based upon statistical analysis of 1,077 device implants, shows the chance for re-operation to either fix or replace the Novacor LVAS is 1.6% between zero and six months; 2.1% between six and 12 months; 11% between 12 and 24 months; and, 16% between 24 and 36 months. The physician's manual now will also include the statement that testing "revealed a single, noncatastrophic, device wear-out mechanism – main bearing wear – that is progressive and has detectable symptoms that can be proactively and non-invasively monitored before wear-out, permitting elective pump replacement."

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