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Belluschi et al. Mini-invasive Surg 2020;4:58 I http://dx.doi.org/10.20517/2574-1225.2020.48 Page 7 of 12

A B

Figure 3. The MitraClip system. On the left, the MitraClip structure with two arms, now 5 mm longer in the XTR version, and grippers (A);
on the right the 24 Fr delivery steerable guiding catheter (B) (Courtesy of Abbott)

was 3.1 ± 1.75 (95%CI: 0.83-8.02). Only 4 patients (4.1%) were reoperated for recurrent severe mitral
regurgitation (MR). At 16 years, CIF of reoperation and recurrence of MR ≥ 3+ with death as a competing
risk were 3.1% ± 1.76% (95%CI: 0.83-8.02) and 5.6% ± 2.47% (95%CI: 2.06-11.83) respectively.

It is of pivotal importance that the long-term outcomes are excellent in patients with degenerative MV
disease, because current guidelines recommend early repair for asymptomatic patients with severe MR,
[2]
whenever long durability is predicted . Providing the patients with the option of a cosmetically favorable
procedure without sacrificing efficacy and long-term durability, will facilitate early surgical correction of
MR before the development of LV dysfunction. Indeed, most of the target population for this approach will
face a long life-expectancy (the mean age of the series previously reported was 35 ± 9 years).

THE ORIGIN OF TRANSCATHETER MITRAL VALVE REPAIR
Simplicity of the edge-to-edge technique enables the possibility of it being translated into a percutaneous
approach and constitutes a milestone in the field of cardiovascular medicine, thus paving the way to an era
[37]
of transcatheter mitral valve repair .

Indeed, the Alfieri’s stitch has inspired the development of percutaneous leaflet repair devices such as the
MitraClip and the PASCAL systems.

The MitraClip system (Abbott, Chicago, IL, USA) was the first device designed to simulate the surgical
edge-to-edge repair. Designed by the Californian start-up Evalve Inc. (purchased by Abbott in 2009), the
MitraClip device [Figure 3] was first implanted in 2003 . It has obtained CE mark and FDA approval
[38]
for treatment of primary MR in 2008 and 2013, respectively. Nowadays, more than 100,000 patients have
been treated with the Abbott MitraClip device. After the feasibility study (EVEREST I trial), in 2011 the
EVEREST II randomized clinical trial (Endovascular Valve Edge-to-edge REpair Study II trial) reported the
[39]
outcome of MitraClip compared to surgery in a 2:1 ratio . A total of 279 patients suffering of moderate-
to-severe or severe MR, both degenerative and functional and with a jet originating from malcoaptation
of the A2-P2 scallops, were enrolled. Despite the fact that the transcatheter repair showed less efficacy
to reduce MR-grade at 1-year, it was found to be superior in terms of safety (major adverse events:
15% clip vs. 48% surgery; P < 0.001, almost exclusively driven by difference in blood transfusion) and
demonstrated similar clinical outcome improvements (primary composite endpoint were 55% and 73% for
the percutaneous edge-to-edge and surgical option, respectively; P = 0.007). The 5-year follow-up revealed
persistence of a significant difference between groups when considering the primary endpoint (44% vs. 64%