The Hamburg TranscathEteR Mitral Valve REplacement RegiStry (HERMES) is a prospective clinical cohort registry aiming to gather follow-up information on short- and long-term outcome of patients with mitral valve disease that undergo transcatheter mitral valve replacement (TMVR) screening. In particular, long-term durability and function of implanted bioprosteses is of utmost interest for both patients and clinicians. Moreover, this study aimes to investigate and compare the different treatment strategies patients undergo after successful or unsuccessful screening for TMVR.

Mitral valve regurgitation (MR) emerges as the most frequent valvular heart disease in developed coun-tries with prevalence increasing with age. Mitral valve repair is the gold standard therapeutic strategy in primary MR and is recommended in patients with secondary MR who are in need of revascularization. However, in patients with secondary MR mitral valve repair is associated with a higher rate of MR recurrence compared to mitral valve replacement. Nevertheless, elderly patients often are at high or prohibitive surgical risk and up to one half of all patients with severe MR are not referred to surgery. Transcatheter edge-to-edge mitral valve repair (TEER) constitutes a feasible and effective alternative, but eligibility for TEER is limited in some cases due to suboptimal anatomy or risk of mitral stenosis. Moreover, MR reduction is less predictable and, again, MR may reoccur. Transcatheter mitral valve replacement (TMVR) represents a complementary therapeutic approach for patients with severe MR. This novel therapy promises to reduce MR as durable as surgical valve replacement while reducing the procedural risk with an interventional approach.

The Hamburg TranscathEteR Mitral Valve REplacement RegiStry (HERMES) is a prospective clinical cohort registry aiming to gather follow-up information on short- and long-term outcome of patients with significant mitral valve disease, at high surgical risk with suboptimal anatomy for TEER, who undergo TMVR screening. In particular, long-term durability and function of implanted bioprosteses will be investigated. Additionally, this study aimes to investigate and compare the different treatment strategies patients undergo after successful or unsuccessful screening for TMVR (i.e., TMVR, TEER, surgery and medical therapy).

Inclusion Criteria:

• Ability to provide written informed consent in accordance with Good Epidemiological Practice and local legislation.
• Individuals over the age of 18 years.
• Patients with clinically relevant mitral valve disease, who undergo screening for TMVR.

Exclusion Criteria:

• Insufficient knowledge of the German language, to understand study documents and interview without translation
• Physical or psychological incapability to cooperate in the investigation

All patients with clinically significant mitral valve regurgitation that undergo screening for Transcatheter Mitral Valve Replacement (TMVR) at University Heart and Vascular Center Hamburg shall be included. This includes inpatients and outpatients of the University Heart and Vascular Center Hamburg and may be extended to patients from other national or foreign centers. Inclusion into the study will take place after written informed consent is obtained. Patients included in interventional device studies (e.g., early feasibility TMVR studies, post-market TMVR studies etc.) may also be included in HERMES.