The MITRAL II Pivotal Trial (Mitral Implantation of TRAnscatheter vaLves).

A prospective multicenter study enrolling high surgical risk patients with severe mitral annular calcification (MAC) and symptomatic mitral valve dysfunction (severe stenosis, ≥ moderate to severe regurgitation, or mixed ≥ moderate stenosis and ≥ regurgitation). There are 2 Arms in this study: 1) "Transseptal (TS) Valve-in-MAC" (ViMAC) Arm, and 2) Natural History of Disease Registry (NHDR) for patients treated with medical treatment only (which includes patients who meet inclusion criteria but can't be treated with transeptal ViMAC due to the presence of anatomical exclusion criteria or other exclusion criteria) and have not had other procedures that may impact outcomes (i.e., alcohol septal ablation or radiofrequency ablation). The study also includes a Registry of Permanently Unassigned" for subjects who undergo preemptive septal ablation procedures (alcohol or radiofrequency) in anticipation of continuing onto ViMAC arm, but are not accepted in the ViMAC Study arm or the patient chooses not to undergo ViMAC procedure.