Replacement and repair of heart valves without opening the chest is one of the largest new opportunities in the cardiovascular space over the next five years. And it is one that Medtronic (Minneapolis) is attempting to mine with a new interventional system designed to reduce the number of times certain patients with congenital heart disease may need open-heart surgery.

Medtronic just reported the first implant procedure in the launch of a feasibility study of its melody transcatheter pulmonary valve and ensemble transcatheter delivery system. The Melody valve and delivery system is used to treat patients requiring congenital pulmonary heart valve replacement. And the company said it is the first of its kind in North America.

The study, a prospective, non-randomized trial, will enroll 30 patients at three U.S. medical centers: at Children's Hospital Boston by investigators James Lock, MD, cardiologist-in-chief and Emile Bacha, MD, senior associate in cardiac surgery; Morgan Stanley Children's Hospital of New York — Presbyterian (New York) by investigators William Hellenbrand, MD, director of catheterization laboratory for congenital heart disease and Ralph Mosca, MD, director of pediatric cardiac surgery; and Miami Children's Hospital (Miami, Florida) by investigators Evan Zahn, MD, chief of cardiology, and Redmond Burke, MD, chief of cardiovascular surgery.

Jill Hennesen, a senior marketing development manager for Medtronic, told Medical Device Daily that the Melody valve and Ensemble delivery system provides another choice for clinicians who are managing patients with congenital heart disease, not just following birth but throughout their lives.

"This is one more treatment option that the interventional cardiologist and cardiac surgeon — who are very closely collaborating in managing these patients — have when deciding what kind of treatment option is going to provide the most benefit to these patients," she said.

The transcatheter approach represents a less invasive approach since the physician can deliver replacement valves via a catheter through the body's cardiovascular system, rather than by opening the chest via insertion through the patient's femoral vein (MDD, Oct. 6, 2006).

Hennesen emphasized the importance of the cardiologist/cardiac surgeon cooperation in treating congenital heart disease because patients suffering from the disease tend to be very sick and usually have to undergo multiple surgeries.

"It's not uncommon for these patients to undergo surgery almost immediately after birth or as infants, depending on the situation," Hennesen said.

John Mayer, MD, senior associate in cardiac surgery at Children's Hospital Boston also stressed the importance of this clinical partnership.

"Effective management of congenital heart defects over a patient's lifetime requires dedicated collaboration between cardiac surgeons and interventional cardiologists," Mayer said. "Together, members of these two disciplines draw on a variety of treatment options and clinical pathways. We hope that the Melody valve will be an important addition to the choices available for our patients."

Medtronic said this type of defect normally requires open-heart surgery early in life to implant a prosthetic or bioprosthetic valved-conduit to establish adequate blood flow from the heart to the lungs. But the functional life span of these conduits is relatively limited and, as a result, most patients with this type of defect may require multiple open heart surgeries to place new valved conduits as they grow over their lifetime.

Thus, Medtronic said it would use this trial to evaluate the Melody valve and Ensemble delivery system as a catheter-based alternative treatment in order to restore pulmonary valve function and prolong the functional life of the right ventricle to pulmonary artery conduits, thus hopefully reducing the need for later open-heart surgeries.

Lock, of Children's Hospital Boston, said the implant procedure was conducted both "clinically and from a quality-of-life perspective for the patient."

According to the American Heart Association (Dallas), heart defects make up the No. 1 birth defect worldwide. In the U.S., more than 25,000 babies are born each year with a congenital heart defect. About 22% of those born with congenital heart disease have defects disrupting the blood flow from the right ventricle to the pulmonary artery.

Patients with this condition tire easily, because the heart over-exerts trying to get oxygenated blood throughout the body.

Medtronic has partnered with Philipp Bonhoeffer, professor and chief of cardiology and director of the Catheterization Laboratory, Great Ormond Street Hospital for Children (GOSH; London), and NuMed Canada (Cornwall, Ontario), a pediatric catheter company in the development of the Melody valve and Ensemble system. A pioneer in transcatheter valve technology, Bonhoeffer implanted the world's first transcatheter valve in September 2000. Medtronic said that, to date, more than 200 patients have been treated with the therapy worldwide.

Hennesen said the feasibility trial is Medtronic's first step towards FDA approval of the device.

The company reported receiving Canadian approval in January (MDD, Jan. 11, 2007) and CE Mark approval in September 2006 of the Medtronic Melody Transcatheter Pulmonary Valve and Ensemble Transcatheter Delivery System.