The Carillon Mitral Contour System safely treated leaky mitral valves even in patients with moderate-to-severe heart failure, and was effective in reducing the backward flow of blood from the left ventricle to the left atrium, according to a late-breaking clinical trial presented May 7 at the 32nd annual scientific sessions for the Society for Cardiovascular Angiography and Interventions (SCAI) in Las Vegas.
The Carillon Mitral Annuloplasty Device European Union Study (AMADEUS) also showed that after treatment, patients experienced less shortness of breath and reported a better quality of life.
"This system is an exciting new option for patients and represents a significant improvement over medical management, the current standard of care," said Tomasz Siminiak, MD, PhD, a professor of cardiology at Poznan University of Medical Sciences, Cardiac and Rehabilitation Hospital Kowanowko in Kowanowko, Poland. He added that the procedure can be performed in under an hour.
The AMADEUS study enrolled patients with functional mitral regurgitation due to an abnormally enlarged heart after a heart attack or some other illness. As the heart gets bigger, the valve opening stretches and the valve flaps no longer come together to form a tight seal. As a result, when the heart contracts, some of the blood in the left ventricle is propelled backward through the leaky valve into the left atrium, instead of being circulated to the rest of the body, resulting in shortness of breath, especially during physical activity.
The Carillon device consists of two anchors connected by a shaping ribbon, made of nitinol, which conforms to the natural contours of the veins. The device is passed through the catheter and into the great cardiac vein. One of the anchors is locked in place to restore the natural shape of the mitral valve and bring the valve flaps together. The second anchor is then locked in place. Imaging studies are used to confirm that the leaky valve is closing properly, and the implant is released. If the results are not satisfactory, the interventional cardiologist can recapture the system.
The AMADEUS study was designed to test the feasibility and safety of the Carillon system for the repair of leaky mitral valves. The study involved 48 patients with moderate-to-severe functional mitral regurgitation, an enlarged heart, reduced cardiac pumping ability, heart failure and limited exercise capacity.
Researchers were able to implant the Carillon device in 30 patients. In this group, echocardiography confirmed the improvement in mitral valve function after both one and six months. For example, the average volume of blood propelled backward through the mitral valve fell from 35 mL before the procedure to 23 mL after one month and 24 mL after six months. Similarly, the average size of the leaky opening between the mitral valve flaps was reduced from 0.25 cm2 before the procedure to 0.17 cm2 after one and six months.
In the 18 patients who could not be treated with the Carillon device--the heart's veins were too small--the device did not adequately reduce the backflow of blood through the mitral valve, or the device pressed on nearby coronary arteries and reduced blood flow to the heart muscle. However, when the coronary arteries are squeezed in this way, it is possible to successfully reposition the device almost half of the time, Siminiak said.
One patient died as a result of kidney failure, which was related to toxicity from the contrast dye used during interventional procedures. Three patients suffered an access-related puncture of the cardiac vein, but all of the blood vessels healed on their own. In three patients, abnormal lab tests hinted that the heart muscle might have been injured, but further investigation showed no problems.
Siminiak is continuing to follow-up patients to determine whether the improvements in mitral valve function are long lasting.
With these results, AMADEUS has demonstrated the safety of this coronary sinus approach and provided early feasibility data on the efficacy of the device in reducing functional mitral regurgitation and improving patient function and quality of life.
The researchers said they have begun discussions with the FDA about an investigational device exemption status for the Carillon system. If approved, this would enable a pivotal randomized clinical trial to be launched later this year. The Carillon system was recently granted CE Mark approval, which allows the device to