An Innovative Percutaneous Procedure for the Mitral Valve
TMCA Transcatheter Mitral Cerclage Annuloplasty
Patients with symptomatic severe mitral valve regurgitation are benefitting from an investigational percutaneous procedure to reduce regurgitation, prevent further annular dilation, and diminish symptoms. As of this date, the procedure has been performed successfully in seven patients nationwide.
“Patients with severe, symptomatic mitral valve regurgitation with underlying cardiomyopathy have been difficult to treat before now,” says Toby Rogers, MD, an interventional cardiologist and study director at MHVI. “They can be very symptomatic, with shortness of breath, edema, and frequent hospitalizations. Surgery is rarely beneficial for these patients.”
Called Transcatheter Mitral Cerclage Annuloplasty (TMCA), the procedure involves a new technique and new devices developed at the National Institutes of Health (NIH). An Early Feasibility Study is underway at just three hospitals in the United States, including MHVI.
TMCA is performed under general anesthesia in the cardiac catheterization lab, supported by transesophageal echocardiography. Currently, the procedure is performed through the jugular vein, but researchers are modifying the device to gain access through the femoral vein.
Here’s How The Procedure Is Performed:
Coronary guidewires and microcatheters navigate through the veins of the heart to create a loop around the leaky mitral valve.
The guidewire is then exchanged for a permanent implant that looks like a shoe-string and incorporates a coronary protection element. The position of the implant is adjusted so the coronary protection element lies directly over any underlying coronary artery to protect it from compression as the device is tightened.
A wishbone-shaped lock is then advanced over the two limbs of the implant suture and the desired tension is adjusted to reduce the mitral regurgitation guided by echocardiography.
The device exerts compressive force on the mitral annulus, reducing regurgitation and preventing further annular enlargement.
TMCA builds on preliminary success with the MitraClip™ device. In the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Trial (COAPT) published in 2018, researchers compared outcomes of patients who received the MitraClip with patients who received medical therapy alone. They found a dramatic reduction in the number of hospital admissions for patients who received the MitraClip. However, the MitraClip does not prevent ongoing enlargement of the mitral annulus, so the valve may begin leaking again in the future.
Other techniques to reduce mitral regurgitation are also being studied at MHVI, including percutaneous valve replacements using different transcatheter techniques rather than open heart surgery, Dr. Rogers says. “We’re at the forefront of a new wave of treatments for patients with symptomatic severe mitral regurgitation.”
To learn more about the procedure, please email Toby Rogers, MD, at [email protected].