*2.2.3.3. Mitralign®*

The Mitralign® (Mitralign, Inc., Tewksbury, MA, USA) is a transcatheter direct annuloplasty system that mimics the Kay-Wooler commissuroplasty [75]. The device allows selective plication of the medial and lateral aspects of the MA by deploying pairs of transannular "pledgets". The procedure is carried out from a transfemoral retrograde approach under live echo and fluoroscopic guidance. Each pledget pair can be pulled together resulting in a segmental posterior annuloplasty [76]. In the CE Mark Trial, the system was successfully implanted in 70.4% of 71 high-risk subjects with FMR [77]. No intraprocedural death occurred, but four (8.9%) patients experienced cardiac tamponade. 30-days and 6-month reported all-cause mortality were 4.4 and 12.2%, respectively. Significant improvements in MR and clinical functional class, reduction in MA dimensions and LV remodeling were demonstrated at 6 months.

#### *2.2.4. Transcatheter multimodal approach for mitral regurgitation*

One of the lessons learned from heart valve surgery is that a combination of diverse techniques addressing different mechanisms of MR may improve long-term outcomes [67]. Recently, first experiences of direct and indirect TMVA after failure of PMVR with MitraClip® have been published [78, 79]. MitraClip® is currently the most widespread technique that focus on MV leaflets, with contrasted effective results. Nevertheless, reported recurrence of significant MR can surpass 20% at 1 year [29]. Notably, transcatheter mitral rings may play a role as valuable adjunct catheter-based procedures to Mitraclip® (or percutaneous chordal replacement) in selected patients (such as very dilated LA and MA).

#### **2.3. Transcatheter mitral valve replacement (TMVR)**

The simpler structure of the aortic valve (AV) has probably facilitated the success of a stentlike transcatheter approach for the treatment of AV disease. On the contrary, the much more complex structure of the MV may explain the slower way to find a safe and effective alternative for TMVR. Many companies have completed first-in-human cases; however, no devices are currently approved beyond compassionate use, and several others remain in preclinical development. These percutaneous MV prostheses vary either in the access site, the design and the anchoring technology within the MA or the subvalvular apparatus [80] (**Figure 1**). Currently, eight different devices have been already implanted in-human since 2012 (CardiAQ®, Neovasc Tiara®, Edwards Fortis®, Tendyne®, Twelve®, Navigate®, Highlife®, Caisson®) [81–84]. These initial experiences showed heterogeneous rates of morbidity and mortality across different platforms and pointed out some important challenging issues that might be determinant in the development of this technique: the LV outflow obstruction, the delivery profile and the access route (transapical vs transeptal). Interestingly, patients with Percutaneous Treatment of Mitral and Tricuspid Regurgitation in Heart Failure http://dx.doi.org/10.5772/intechopen.68493 127

**Figure 1.** Current mitral valve platforms under development.

(2 of 31 patients, neither procedure nor device-related). At 30 days, 22 of the 25 patients (88%) had MR grade ≤ 2+. Following results of this trial showed persistent reduction in MR (92% MR ≤ 2+) and improvement in functional class (77% NYHA I–II) at 24-month follow up. Reported procedural success rate (reduction in at least one grade in MR at discharge) was 86%. In 2017, an

The Mitralign® (Mitralign, Inc., Tewksbury, MA, USA) is a transcatheter direct annuloplasty system that mimics the Kay-Wooler commissuroplasty [75]. The device allows selective plication of the medial and lateral aspects of the MA by deploying pairs of transannular "pledgets". The procedure is carried out from a transfemoral retrograde approach under live echo and fluoroscopic guidance. Each pledget pair can be pulled together resulting in a segmental posterior annuloplasty [76]. In the CE Mark Trial, the system was successfully implanted in 70.4% of 71 high-risk subjects with FMR [77]. No intraprocedural death occurred, but four (8.9%) patients experienced cardiac tamponade. 30-days and 6-month reported all-cause mortality were 4.4 and 12.2%, respectively. Significant improvements in MR and clinical functional class, reduction in MA dimensions and LV remodeling were demonstrated at 6 months.

One of the lessons learned from heart valve surgery is that a combination of diverse techniques addressing different mechanisms of MR may improve long-term outcomes [67]. Recently, first experiences of direct and indirect TMVA after failure of PMVR with MitraClip® have been published [78, 79]. MitraClip® is currently the most widespread technique that focus on MV leaflets, with contrasted effective results. Nevertheless, reported recurrence of significant MR can surpass 20% at 1 year [29]. Notably, transcatheter mitral rings may play a role as valuable adjunct catheter-based procedures to Mitraclip® (or percutaneous chordal replacement) in

The simpler structure of the aortic valve (AV) has probably facilitated the success of a stentlike transcatheter approach for the treatment of AV disease. On the contrary, the much more complex structure of the MV may explain the slower way to find a safe and effective alternative for TMVR. Many companies have completed first-in-human cases; however, no devices are currently approved beyond compassionate use, and several others remain in preclinical development. These percutaneous MV prostheses vary either in the access site, the design and the anchoring technology within the MA or the subvalvular apparatus [80] (**Figure 1**). Currently, eight different devices have been already implanted in-human since 2012 (CardiAQ®, Neovasc Tiara®, Edwards Fortis®, Tendyne®, Twelve®, Navigate®, Highlife®, Caisson®) [81–84]. These initial experiences showed heterogeneous rates of morbidity and mortality across different platforms and pointed out some important challenging issues that might be determinant in the development of this technique: the LV outflow obstruction, the delivery profile and the access route (transapical vs transeptal). Interestingly, patients with

RCT comparing Cardioband® versus stand-alone OMT will start recruiting in the USA.

*2.2.4. Transcatheter multimodal approach for mitral regurgitation*

selected patients (such as very dilated LA and MA).

**2.3. Transcatheter mitral valve replacement (TMVR)**

*2.2.3.3. Mitralign®*

126 Interventional Cardiology

poor ejection fraction presented the higher rates of adverse outcomes and might not benefit from this procedure.

Recently, promising results from the Tendyne® feasibility trial have been published [85]. In this study 30 high-risk patients (mean age 75.6 years) with predominantly FMR (76.6%) grade 3 or 4 underwent TMVR. Successful device implantation was achieved in 28 patients (93.3%). No acute major cardiovascular adverse events were reported. One patient died 13 days after TMVR from hospital-acquired pneumonia and prosthetic leaflet thrombosis was detected in one patient at follow-up. At 30 days, transthoracic echocardiography showed mild central MR in 1 patient, and no residual MR in the remaining 26 patients with valves *in situ*. A significant decrease in LV dimensions was documented. Seventy-five percent of the patients reported mild or no symptoms at follow-up. Successful device implantation free of cardiovascular mortality, stroke and device malfunction at 30 days was 86.6%.
