Georg Nickenig (Department of Cardiology, Heart Center Bonn, University Hospital Bonn, Bonn, Germany) and others report in the Journal of the American College of Cardiology that the Mitralign percutaneous annuoplasty system (MPAS, Mitralign) is a feasible and safe treatment for high-risk patients with functional mitral regurgitation. The system was CE mark approved for functional mitral regurgitation earlier this year.
Nickenig et al state that the current treatment options for functional mitral regurgitation are not optimal, calling the prognostic and clinical benefit of surgical management “controversial” in this context. They add that the use of percutaneous edge-to-edge repair (MitraClip, Abbott Vascular) is also “a matter of debate” because of its “limited approach by targeting the mitral valve leaflets only.”
Therefore, the authors reviewed the use of MPAS in high-risk patients with functional mitral regurgitation, noting: “interventional therapies mimicking the surgical gold standard for functional mitral regurgitation treatment to reduce annular dimensions may be the preferred treatment option in this setting”. They explain that MPAS reduces mitral valve annular dilation and, therefore, “directly addresses the underlying pathology of functional mitral regurgitation and transseptal puncture is not needed during this procedure”.
In the prospective, multicentre, single-arm, feasibility study, 71 patients with moderate-to-severe functional mitral regurgitation were assigned to undergo percutaneous direct annuoplasty with the Mitralign system. After the first 20 patients were recruited, following technical refinements to the system, the remaining 51 patients were assigned to the second-generation version of MPAS. The primary endpoint of the study was to assess the safety and the performance of the system, with safety being defined as the 30-day composite of death, stroke, myocardial infarction, or emergent surgery and intervention.
Of the 71 patients enrolled in the study, 50 patients underwent successful treatment with device. At 30 days, data were available for 45 patients—consisting of 20 who were implanted with one pair of pledget devices and 25 who were implanted with two pairs of pledget devices. Nickenig et al comment that “there were no intraprocedural deaths and no necessity for acute conversation to open heart surgery.” Also, all-cause mortality (at 30 days) was 4.4%; lower (but not to a significant extent) than patients who did not receive treatment (14.3%; p=0.2 for the comparison). However, the authors note that the rate of pericardial tamponade (8%) was “relatively high” and may be associated with a learning curve. “All patients were treated uneventfully with pericardiocentesis; however, this safety aspect must be addressed with improved implantation strategies,” Nickenig et al state.
At six months (data were available for 30 patients), the rate of all-cause mortality was 12.2%, one patient had undergone non-emergent mitral valve surgery, and seven had received a MitraClip device. Overall, the severity of mitral regurgitation was improved in 50% of treated patients, stabilised and unchanged in 34.6% of patients, and worsened in 15.4%. The authors report: “When comparing patients treated with one or two pairs of pledgets, the benefit of percutaneous annuloplasty procedure in terms of mitral regurgitation severity reduction was pronounced in those patients who were successfully treated with two pairs of pledgets.” They add that it “seems reasonable to assume” that the study’s overall results would have been “more favourable” if all patients in the study received device treatment with multiple pairs of pledgets.
Among treated patients, at six months, heart failure symptoms and the six-minute walking distance were both significantly improved compared with baseline. There was also a trend towards improved quality of life.
The authors conclude: “Percutaneous annuloplasty with MPAS is feasible and safe in high-risk functional mitral regurgitation patients. The treatment initiates left ventricular reverse remodelling and provides clinical improvement during six months after treatment.”
Nickenig told Cardiovascular News: “The Mitralign system could be of use for patients with functional mitral regurgitation and dilation of the mitral annulus.”