NHLBI SESAME (SEptal Scoring Along Midline Endocardium) Early Feasibility Study
Background:

Some people have a condition in which the wall (septum) that separates the two main pumping chambers of the heart is too thick. This thick septum causes a condition called "left ventricular outflow tract obstruction" (LVOTO), which reduces blood flow out of the heart. LVOTO can cause serious heart disease; symptoms may include shortness of breath, chest pain, heart failure, or death. Researchers want to find better ways to treat LVOTO.

Objective:

To test a new procedure where excess tissue is sliced away from the septum in people with LVOTO. This procedure is called "septal scoring along midline endocardium" (SESAME).

Eligibility:

Adults aged 21 years with LVOTO.

Design:

Participants will have baseline tests. They will have imaging scans and tests of their heart structure and function. They will take a walking test and answer questions about how their heart condition affects their life.

Participants will stay in the hospital 2 to 6 days for the SESAME procedure.

They will be completely or partially asleep for the procedure. A tube will be inserted into the mouth and down the throat to take pictures of the heart. Pictures may also be taken with a tube inserted inside the heart.

Next, tubes will be inserted into the groin and guided through the blood vessels up to the heart. Guidewires will be inserted into the heart. Doctors will watch the path the wires take with x-rays and ultrasound. When the wire is in the correct place, it will be electrified to slice excess tissue away from the septum.

Participants will have 3 follow-up visits within 1 year.
- EligibilityCriteria: INCLUSION CRITERIA:  In order to be eligible to participate in the study, candidates must meet all of the following criteria:  Adults age >= 21 years  Requires debulking of left ventricular septum for one of three phenotypes  1: Hypertrophic cardiomyopathy; OR 2: Left ventricular septal hypertrophy, mitral valve disease and/or aortic valve stenosis warranting/following transcatheter heart valve implantation, WITH intracameral gradient >= (30mmHg peak while resting; 50mmHg peak when provoked); OR 3: Left ventricular septal hypertrophy, mitral valve disease warranting transcatheter heart valve implantation, and risk of iatrogenic left ventricular outflow tract obstruction (LVOTO), Neo-LVOT <= 200 mm^2, WITHOUT intracameral gradient >= (30mmHg peak while resting; 50mmHg peak when provoked)  Septal diastolic thickness on CT:  Total >=12 mm, and Predicted residual septal thickness >= 6 mm, and Predicted laceration depth >= 6 mm  Severely symptomatic, any of  NYHA Class III or greater Canadian Angina Class CCS III or greater Explicitly chooses investigational SESAME over conventional treatment approaches including (1) cardiac myosin inhibitor therapy, if eligible (HCM only); (2) transcoronary alcohol septal ablation, if eligible; or (3) surgical left ventricular myotomy and/or myectomy, if eligible Concurrence of the multidisciplinary institutional heart team that the candidate is at high risk for surgical myectomy Concurrence of the study Central Clinical Eligibility Committee Willing to return for all scheduled follow-up activities, and eligible or able to undergo required protocol and testing  Additional selection criteria for Hypertrophic Cardiomyopathy  - High risk of surgical myotomy/myectomy according to the multidisciplinary heart team  EXCLUSION CRITERIA:  An individual who meets any of the following criteria will be excluded from participation in this study:  Does not consent to participate, or unable to consent to participate Requires antegrade SESAME access (because of mechanical aortic valve) Prior completed transcoronary alcohol septal ablation, or prior surgical myectomy Pregnant Hemodynamic instability or emergency procedure eGFR < 30 mL/min/1.73m^2 Survival despite successful procedure expected < 12months - HealthyVolunteers: No - Gender: All - MinimumAge: 21 Years - MaximumAge: 99 Years - StdAgeList: Adult, Older Adult