Catheter-based mitral valve repair with MitraClip is the best-studied type of percutaneous mitral valve therapy, said Ted Feldman, Evanston Hospital, NorthShore University Health System, Evanston, USA, at the International Symposium on Endovascular Therapy (ISET) in Miami.
The EVEREST II (Endovascular valve edge-to-edge repair study) study assessed the safety and effectiveness of the MitraClip device (Abbott Vascular) in patients with significant mitral regurgitation at high risk of surgical mortality rate. The study, published by Feldman et al (N Engl J Med 2011;364:1395–1406), concluded that although percutaneous repair with the MitraClip device “was less effective at reducing mitral regurgitation than conventional surgery, the procedure was associated with superior safety and similar improvements in clinical outcomes.”
A substudy was done on high risk patients. An analysis of the acute and 12-month results of 78 patients showed that the survival rate at one year was 76% in the high risk study and 55% in the concurrent comparator group (p=0.047) of screened concurrently but not enrolled patients.
Feldman showed delegates research behind various other mitral valve devices, including the Carillon Mitral Contour System (Cardiac Dimensions). The TITAN trial showed 40% reduction in mitral regurgitation, improvements in reverse remodeling and functional improvement in patients implanted with the device. “Outcomes in terms of reduced mitral regurgitation and improved chamber function are notable,” he said.
The future of the field may be direct annuloplasty using different delivery devices, including the transventricular approach, which is used in the Mitralign Percutaneous Annuloplasty System or the Guided Delivery System, Feldman said. In this transcatheter procedure, surgical implants are placed directly into the mitral annulus and tensioned through a catheter to reduce the annular circumference, thus mimicking the surgical techniques.
One of the most interesting devices is the Myocor Surgical Coapsys System, he said. This is a novel approach that uses a cathether passed through the left ventricle to reshape the left ventricle and reduce the mitral regurgitation. In the RESTOR-MV (Randomized evaluation of a surgical treatment for off-pump repair of the mitral valve) trial, the system was shown to reduce mortality. The investigators concluded that “patients with functional mitral regurgitation requiring revascularisation treated with ventricular reshaping rather than standard surgery had improved survival and a significant decrease in major adverse outcomes. This trial validates the concept of the ventricular reshaping strategy in this subset of patients with heart failure.”
Another innovation in the field is transcatheter mitral valve replacement, Feldman noted. This approach will use a catheter to deliver a new mitral valve. The major challenge for valve replacement is anchoring of the new valve in the native annulus.
“There is a lot happening in the field, and we will see steady progress over the next couple of years,” Feldman concluded.
