Interventional vs. surgical mitral valve therapy. Which technique for which patient?

Mitral regurgitation (MR) is the most frequent valvular heart disease in developed countries. Surgical repair represents the optimal treatment for severe degenerative MR; however, surgical correction of functional MR is controversial. The Euro Heart Survey showed that up to 50 % of patients with severe MR are today denied surgical treatment. Therefore, new transcatheter techniques have been developed to treat MR with less invasive approaches. Currently, the device with the widest clinical use is the MitraClip System. In this scenario, a multidisciplinary team approach is key in providing optimal individually tailored treatment for patients with MR.

Review of the MitraClip clinical evidence.

MitraClip system is the only catheter-based device for percutaneous mitral valve repair available for clinical use, after receipt of the CE Mark in 2008, while it is currently under review for FDA approval in the US. To date, over 3500 MitraClip implants have been performed worldwide, mainly in high risk surgical patients. The aim of this review is to review all the current evidences of the MitraClip therapy in an aim to define its clinical role in the treatment of mitral regurgitation (MR).

Patient selection for MitraClip therapy impaired left ventricular systolic function.

Mitral regurgitation (MR) is a disabling disease associated with poor prognosis and high incidence of clinical events if left untreated. To reduce the invasiveness of the surgical approach, different types of transcatheter procedures are becoming available. The MitraClip procedure (Abbott Vascular Inc. Menlo Park, CA, USA) is yet the only catheter-based procedure available in clinical practice at the moment. The device has been evaluated in a number of preclinical studies, registries and in FDA approved clinical trials. (EVEREST trial, ACCESS-EU trial). Indication and timing of intervention is a crucial step in the diagnostic-therapeutic pathway of patients with mitral regurgitation. The aim of this review is to clarify the potential of MitraClip in clinical practice, particularly focusing on patient selection for this novel therapy. Patient selection and overall decision making is strongly influenced by anatomical and clinical factors. Decision-making in degenerative MR (DMR) vs. functional (FMR) can be quite different. Generally, MitraClip is effective in treating either type II or IIIb dysfunction (at the moment FMR is the main indication for MitraClip in Europe, according to the ACCESS registry data). The relative role of MitraClip and surgery in the management of patients with MR is still unclear. From the global initial experience, MitraClip therapy could be complementary to surgery in those patients at high risk for surgery who have ideal anatomical characteristics for implantation. The procedure is quite predictable in patients with favorable anatomy. In patients with suboptimal anatomy, if the risk of surgery is too high, MitraClip could be still indicated sometimes. Our preliminary experience suggests that in patients with DMR, the EVEREST anatomical criteria are strong predictors of early and mid-term success. According to it, MitraClip therapy is appropriate in those DMR patients with high surgical risk and ideal anatomy for clip implantation according to the EVEREST criteria. In FMR refractory to medical therapy and resynchronization therapy, MitraClip could be considered as first option therapy, particularly in those patients with comorbidities, or advanced age, being the operative risk of surgery above 5% in this population. In the future, novel devices, improved knowledge, more efficient imaging and transcatheter mitral prosthetic valve implantation may expand the indications to those patients currently not treated by MitraClip for anatomical unsuitability, and may improve the results both in term of early efficacy and long term durability.