New Clip May
Offer Non-Surgical Repair of Mitral Regurgitation
November / December 2004
EVEREST I is the only study approved by the FDA under an
Investigational Device Exemption to research the percutaneous
treatment of mitral regurgitation (MR) utilizing the Evalve
Clip™. Interventional cardiologists at Penn are participating
in this investigational clinical trial, helping to pioneer
a novel approach to repair insufficient or leaky mitral valves.
This procedure may eliminate the need for open heart surgery
for some patients with severe MR. The condition occurs when
the flaps or leaflets of the mitral valve fail to close properly
and allow blood to leak backward through the valve to the
atrium.
Performed in the cardiac catheterization laboratory under
general anesthesia, the procedure uses standard flouroscopic
and echocardiographic imaging. After routine transseptal access,
the tiny, metallic clip is introduced, positioned and, once
MR has been adequately reduced, secured to the valve. The
patient may be discharged as soon as one day after the procedure.
The Evalve Clip was designed to perform an edge-to-edge (Alfieri
technique) repair of the mitral valve in a beating heart as
opposed to the conventional, open surgical approach. The edge-to-edge
technique involves apposing the middle scallops of the anterior
and posterior leaflet with a stitch creating a so-called “dual”
or “double orifice” mitral valve. This approach
has now been successfully used to treat degenerative MR due
to prolapse of either one or both leaflets and for functional
regurgitation secondary to ischemia and/or
cardiomyopathy.
“Although the Alfieri technique is used frequently
in Europe, it has not been practiced as regularly in the United
States, largely because it is a non-anatomic repair. When
performing an open procedure, the surgeon is more likely to
repair the valve using a technique that gives the closest
appearance to what it should look like when it was working
properly,” says
Howard C. Herrmann, MD, professor of cardiovascular medicine
and director of interventional cardiology and Cardiac Catheterization
Laboratories at the Hospital of the University of Pennsylvania.
“This is a novel, non-invasive approach to creating
a different type of valve.”
In addition to being the most common type of heart valve
insufficiency, MR is a familiar finding in patients with heart
failure and has a detrimental effect on left ventricular function.
Patients with mild MR may remain asymptomatic for many years.
However, moderate to severe MR gradually produces ventricular
contractile dysfunction and dilation. The most common symptoms
of MR include shortness of breath with exercise or at rest,
congestive heart failure, swelling of the extremities, and
decreased exercise tolerance. Successful surgery and now,
clip placement, with MR reduction will improve a patient’s
functional capacity, exercise tolerance, and ability to breathe.
Approximately 50,000 mitral valve replacement operations
are performed annually in the United States. It is estimated
that up to a million people may have some degree of MR that
is either not severe enough to warrant open heart surgery
or the patient is not a candidate for open heart surgery.
Some of these patients may, however, be candidates for less
invasive procedures.
“The early results are encouraging. There have been
no complications or safety issues and the majority of patients
have experienced an improvement in the severity of their MR,”
adds Dr. Herrmann. Performed for the first time in June 2003,
the Evalve clip surgery has been used to treat 16 patients
nationwide, with three of these performed by Dr. Herrmann
at Penn.
“Eventually, we hope to identify patients who will
routinely obtain excellent results with this procedure and
other patients for whom surgery is either relatively contraindicated
or for whom a perfect result with complete resolution of their
mitral regurgitation is not necessary,” says Dr. Herrmann.
“This procedure represents the early stages of what
may eventually be other percutaneous treatments for valvular
heart disease. Twenty-five years ago when balloon angioplasty
was invented for coronary artery disease, no one would have
predicted that today interventional cardiologists would perform
more revascularization procedures than cardiac surgeons. I
anticipate more innovations and engineering advances that
will allow us to eventually treat a substantial number of
patients with valvular heart disease without surgery,”
adds Dr. Herrmann.
Dr. Herrmann and his colleagues are actively investigating
other techniques to percutaneously repair valves, including
a clip that can be placed in the coronary sinus to remold
the annulus and change the shape of the mitral valve to improve
the closing of the leaflets, and a stented bioprosthetic valve
to treat malfunctions in the aortic valve.
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