NEW ORLEANS, La. (March 25, 2007) — Advances in catheter-based therapies continue to expand non-surgical treatment options for patients with a wide range of cardiovascular conditions, according to research presented today at the American College of Cardiology's Innovation in Intervention: i2 Summit 2007 in New Orleans, La. Innovation in Intervention: i2 Summit is an annual meeting for practicing cardiovascular interventionalists sponsored by the American College of Cardiology in partnership with the Society for Cardiovascular Angiography and Interventions. New catheter-based, or percutaneous, techniques are proving their mettle in restoring valve function, maintaining blood flow through branch arteries during stenting, and temporarily assisting the heart in patients with life-threatening shock as a result of a heart attack.
A Percutaneous Approach to Treat Moderate to Severe Mitral Valve Regurgitation Using the Edwards MONARC™ System - Interim Results of the Feasibility Experience (Presentation Number: 2406-13)
New studies are exploring the effectiveness of catheter-based approaches to repairing the mitral valve, the dual-flapped portal that controls blood flow between the left atrium (the upper chamber) and left ventricle (the lower chamber) of the heart. When the heart becomes enlarged, the flaps, or leaflets, of the mitral valve no longer fit snugly together when closed. The result: As the ventricle contracts, a portion of the blood shoots backward, or regurgitates, into the atrium rather than circulating to the rest of the body. Until recently, major surgery was the only way to reshape the mitral valve; therefore, many patients received medical therapy alone.
"The standard treatment for functional mitral regurgitation is medical therapy, or surgical replacement or repair of the mitral valve, which is associated with the risks of open-heart surgery," said Dr. Karl-Heinz Kuck, cardiology director at Allgemeines Krankenhaus St. Georg, Hamburg, Germany.
A team led by Dr. Kuck evaluated one approach to non-surgical mitral repair, the MONARC system (Edwards Life Sciences, Irvine, CA). The MONARC system consists of two stent-like anchors, a spring bridge that connects the anchors, and a biodegradeable element within the bridge. Mounted on a catheter, the device is threaded into the coronary sinus, a vein in the heart that runs next to the tissue ring, or annulus, that defines the opening of the mitral valve. The anchors are implanted in separate positions in the coronary sinus, so that the metal bridge surrounds a significant portion of the mitral valve annulus. Over several weeks, the spring bridge shortens, creating tension around the mitral valve, gradually reshaping the leaflets and surrounding structures. The result is an improvement in leaflet function and a reduction in mitral regurgitation.
The researchers evaluated the safety and feasibility of the MONARC system in patients with moderate-to-severe mitral regurgitation. To date, they have interim data on 36 patients. The system was successfully implanted in 32 of 36 patients, all without serious complications. Approximately three months after implantation of the MONARC system, echocardiography showed significant improvement in mitral regurgitation in most patients.
Dr. Kuck will present this study on Sunday, March 25, at 3:00 p.m. in La Nouvelle Orleans C.
A Novel Device for the Enhancement of Percutaneous Coronary Intervention in Bifurcation Lesions: First-In-Man Experience (2406-11)
In the first study of its kind in humans, a novel stenting catheter improved the treatment of coronary plaque located at the branch between two arteries, simplifying the positioning and orientation of the stent and avoiding the complications that can arise when a side branch becomes blocked during the procedure.
"The sideKick stent delivery system allows for stent deployment in the main coronary branch while protecting the side branch, perfectly positioning the stent struts so there is minimal interference with the side branch," said Dr. David Meerkin, director of experimental cardiology at Shaare Zedek Medical Center in Jerusalem, Israel. If the side branch was to become blocked by the stent in the main artery, blood flow could be cut off to part of the heart, causing a heart attack.
The sideKick catheter is designed with openings on the side, through which a flexible wire can be passed into a side artery. In addition, a unique set of markers enables precise positioning of the stent in relation to the side branch.
To evaluate the safety and feasibility of the sideKick stenting system, Dr. Meerkin and his colleagues recruited 17 patients, treating a total of 20 branch-point plaques. The procedure was successful in all cases and was without any serious complications. It was necessary to inflate a balloon to widen the side branch after stenting in only 4 patients.
"This system may offer the interventional cardiologist a simpler procedure with less risk of side-branch loss and subsequent heart attack," Dr. Meerkin said.
Dr. Meerkin will present this study on Sunday, March 25, at 2:40 p.m. in La Nouvelle Orleans C.
Left Ventricular Assist Device (Impella LP 2.5) Versus Intraaortic Balloon Counterpulsation for Patients With Cardiogenic Shock by Myocardial Infarction: A Prospective, Randomized Trial (ISAR-SHOCK) (Presentation Number: 2406-9)
A miniature pump inserted by catheter into the left ventricle is significantly better than a commonly used pulsating balloon system for maintaining blood circulation in patients who have gone into shock after a severe heart attack, according to the ISAR-SHOCK study, the first prospective, randomized comparison of the two devices.
"Cardiogenic shock is a life-threatening condition with a mortality of 50 percent to 60 percent," said, Dr. Melchior Seyfarth, a professor of cardiology at Deutsches Herzzentrum, Technische Universitaet, Muenchen, Germany.
"This new pump more effectively supports the circulation, providing a bridge for the patient and the failing heart until the heart is able to recover."
The Impella LP 2.5 (Abiomed, Danvers, MA) is a rotating pump that is placed in the left ventricle over a wire, pumping blood into the aorta at flow rates of up to 2.5 L/min. By comparison, intra-aortic balloon counterpulsation (IABP)—standard therapy—passively improves circulation by through inflation of a balloon in the aorta when the heart is filling and deflation of the balloon when the heart is contracting.
To compare the effectiveness of the two devices, Dr. Seyfarth and his colleagues randomly assigned 26 patients who were in shock following a heart attack to circulatory support with the IABP or the Impella pump. After 20 minutes, they found that the amount of blood being circulated by the heart was significantly better with the Impella pump. Cardiac output increased by 1.1 L/min in patients supported by the Impella pump, as compared to 0.2 L/min with the IABP. Investigators also noted a trend toward better mean arterial pressures with the Impella pump, which produced an increase of nearly 9.8 mmHg, as compared to a decrease of 1.2 mmHg with the IABP. During and after hospitalization, they measured additional indicators of blood circulation and clinical status as well.
Dr. Seyfarth will present the ISAR-SHOCK study at the Late Breaking Emerging Technologies and Innovations session on Sunday, March 25, at 2:30 p.m.
The American College of Cardiology (www.acc.org) represents the majority of board certified cardiovascular physicians in the United States. Its mission is to advocate for quality cardiovascular care through education, research, promotion, development and application of standards and guidelines- and to influence health care policy. ACC.07 and the i2 Summit is the largest cardiovascular meeting, bringing together cardiologists and cardiovascular specialists to share the newest discoveries in treatment and prevention, while helping the ACC achieve its mission to address and improve issues in cardiovascular medicine.