NHLBI DIR LAMPOON Study: Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Implantation

Background: Transcatheter mitral valve replacement (TMVR) is recommended for some people with mitral valve heart problems. But the usual TMVR techniques might cause an obstruction for some people. A new technique is called LAMPOON. It may have less risk of obstruction. Participants in this study will be among the first in the world to have this technique done. Objectives: To test the safety and effectiveness of the LAMPOON technique in TMVR. Eligibility: Adults ages 21 and over who are recommended to have TMVR with LAMPOON Design: Participants will be screened with medical history and exam and by review of medical records. Participants will have blood tests, an ECG, a heart CT scan, and an echocardiogram before the procedure. Participants will have TMVR with LAMPOON. They will have anesthesia or moderate sedation for the procedure. Doctors will use a wire to split the diseased mitral valve and move it out of the way before inserting the artificial mitral valve. Participants will recover in an inpatient recovery unit. They will repeat the previous tests before leaving the hospital, 1 month later, 6 months later and 1 year later. They will have yearly follow-up phone calls for about 5 years. In the event of a participant's death, researchers will ask for an autopsy and to analyze the heart. Permission for this is not required as part of the study.