NHLBI SESAME (SEptal Scoring Along Midline Endocardium) Multi-Center Prospective Study Using Improvised Off-Label Devices

This is an early study of a catheter-based minimally invasive procedure called SESAME to slice thick heart muscle as described below.

Excessively-thick heart muscle can cause serious heart disease, especially heart failure with preserved ejection fraction, which causes shortness of breath and heart failure symptoms such as edema (swelling) and pulmonary congestion (lung water). Specific circumstances of excessively-thick heart muscle can block outflow of blood from the main heart pumping chamber (left ventricle).

We developed a catheter technique called SESAME (SEptal Scoring Along Midline Endocardium) to slice the excessively-thick heart muscle causing such problems. SESAME can be used in patients who have symptoms related to excessively-thick heart muscle in a part of the heart that restricts blood ejection from the heart; the problem is called "left ventricular outflow tract obstruction (LVOTO)." One group of patients who might benefit from SESAME suffer from a common inherited heart muscle disease called "hypertrophic cardiomyopathy (HCM)." Patients with HCM and symptoms from LVOTO can be treated with medications, open heart surgery, or catheter-based destruction of heart muscle in "alcohol septal ablation." If these treatments fail or are not suitable, then SESAME may be an option, because it resembles surgery treatment without open heart surgery.

Other groups of patients that might benefit are those with heart valve diseases, of the mitral or of the aortic valve, or both, along with excessively-thick heart muscle. These patients may be poor candidates for standard surgical valve repair or replacement because of high risk of complications or death. Such patients might be eligible for non-surgical transcatheter mitral valve replacement, either standard or unapproved ("off-label") or research ("investigational"), but are poor candidates because of risk of LVOTO. Moreover, about half have LVOTO making heart valve symptoms worse. Treating the LVOTO alone may improve symptoms enough that heart valve treatment can be delayed or avoided.

This is a sponsor-investigator IDE study of SESAME performed at a small number of centers that have adopted the technique in the practice of medicine, in order better to characterize how well it works and whether it is safe.

Participating centers already perform SESAME in the practice of medicine using improvised, off-label devices. This protocol allows prospective oversight, standardized technique constraints, central imaging review, independent monitoring, and formal safety adjudication. In addition, the investigational protocol does not function as the gatekeeper for access to SESAME.

The investigators are not affiliated with the guidewire manufacturer and do not seek marketing approval or clearance for SESAME.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Cardiac septal reduction therapies - to relieve left ventricular outflow tract obstruction from transcatheter mitral valve replacement or hypertrophic cardiomyopathy - have inherent limitations including dependence on coronary anatomy, high pacemaker implantation rate, and surgical morbidity. We developed a novel transcatheter ventricular myotomy called SEptal Scoring Along the Midline Endocardium (SESAME) that relies on intramyocardial guidewire navigation and transcatheter electrosurgery. SESAME has been performed on hundreds of patients worldwide using improvised (off-label and bedside-modified commercially available) devices. Recent benchtop refinements in SESAME technique, using improvised devices, are predicted to reduce the likelihood of serious complications such as ventricular perforation, iatrogenic ventricular septal defect, and death.

This sponsor-investigator IDE study systematically characterizes the safety and outcomes of SESAME at up to 10 enrolling sites. SESAME is performed as septal reduction therapy in a heterogeneous group of participants, including (1) symptomatic hypertrophic cardiomyopathy with resting or provoked left ventricular outflow obstruction (LVOTO); and (2) severe symptomatic mitral valve disease at high risk of standard heart surgical therapy and requiring later transcatheter mitral valve implantation combined with manifest or potential LVOTO. This study attempts to capture generalizable knowledge from as many patients as possible who undergo SESAME, and to add a limited number of research procedures to characterize the safety and provisional effectiveness of SESAME.

Participating centers already perform SESAME in the practice of medicine using improvised, off-label devices. This protocol allows prospective oversight, standardized technique constraints, central imaging review, independent monitoring, and formal safety adjudication. In addition, the investigational protocol does not function as the gatekeeper for access to SESAME.

The investigators are not affiliated with the guidewire manufacturer and do not seek marketing approval or clearance for SESAME.

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20010
        • MedStar Washington Hospital Center
        • Contact:
          • Toby Rogers, M.D.
          • Phone Number: 202-877-5975
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • Emory University Hospital
        • Contact:
          • Vasilis Babaliaros, M.D.
          • Phone Number: 678-557-4514
        • Contact:
    • Massachusetts
      • Boston, Massachusetts, United States, 02215
        • Beth Israel Deaconess Medical Center
        • Contact:
          • James McCabe, M.D.
          • Phone Number: 617-667-8800
    • New York
      • Roslyn, New York, United States, 11576
        • St. Francis Hospital & Heart Center
        • Contact:
          • Jaffar M Khan, M.D.
          • Phone Number: 516-390-9640
      • The Bronx, New York, United States, 10461
        • Montefiore Medical Center: Einstein Campus
        • Contact:
          • Mohamed Azeem Latib, M.D.
          • Phone Number: 718-920-4212
    • Pennsylvania
      • York, Pennsylvania, United States, 17403
        • WellSpan York Hospital
        • Contact:
          • Christopher G Bruce, M.D.
          • Phone Number: 717-851-2441
    • Virginia
      • Charlottesville, Virginia, United States, 22908
        • Univ. of Virginia
        • Contact:
          • John Saxon, M.D.
          • Phone Number: 434-243-1000
      • Roanoke, Virginia, United States, 24014

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 100 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

  • INCLUSION CRITERIA

  • Adults age >= 21 years

  • Requires left ventricular septal reduction therapy for one of two indications

    1. Obstructive hypertrophic cardiomyopathy with symptomatic left ventricular outflow tract obstruction (30mmHg peak while resting OR 50mmHg peak when provoked); OR
    2. Planned transcatheter mitral valve replacement is feasible but limited by risk for iatrogenic left ventricular outflow tract obstruction, defined on contrast-enhanced CT as skirt-neo-LVOT <200^2
  • Planning to undergo SESAME transcatheter myotomy

  • Septal diastolic thickness on CT as measured by the NHLBI central laboratory before enrollment:

    • For obstructive hypertrophic cardiomyopathy, >=14mm;
    • For transcatheter heart valve replacement, >=12mm

and

  • Intended minimum diastolic residual septal thickness >=6mm

    -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 (obstructive 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 and that SESAME is an appropriate septal reduction strategy for this candidate.

    • Willing to return for all scheduled follow-up activities, and eligible or able to undergo required protocol and testing

EXCLUSION CRITERIA

  • Does not consent to participate, or unable to consent to participate
  • Pregnant
  • Hemodynamic instability or emergency procedure
  • Mechanical aortic valve
  • eGFR < 30 mL/min/1.73m^2

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: SESAME Arm

The intervention is the SESAME procedure.

The intervention is the SESAME procedure, a catheter-based septal myotomy performed in adults with symptomatic or high-risk LVOT obstruction. It uses off-label Astato XS 20/40 guidewires and the NHLBI LCI electrosurgery timing appliance to create a controlled longitudinal laceration through the hypertrophied interventricular septum under fluoroscopic and echocardiographic guidance, with energy delivery limited to short pulses and cooling intervals to reduce thermal injury; all participants receive the same procedure, with follow-up assessments afterward.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
SESAME Technical Success
Time Frame: Completion of SESAME procedure

The primary outcome is technical success, defined as the participant being alive and having a successful SESAME laceration, with post-procedure CT showing that the achieved minimum residual septal thickness matches the planned thickness within 20%.

Completion of SESAME procedure
SESAME Safety
Time Frame: 30 days after SESAME procedure

The primary safety endpoint is freedom at 30 days from all-cause mortality, any stroke (disabling or non-disabling), and major SESAME-related cardiac structural complications requiring intervention, such as iatrogenic ventricular septal defect, aortic or mitral regurgitation, tamponade, or new permanent pacemaker implantation.

30 days after SESAME procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Robert J Lederman, M.D., National Heart, Lung, and Blood Institute (NHLBI)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

November 9, 2026

Primary Completion (Estimated)

March 1, 2029

Study Completion (Estimated)

March 1, 2030

Study Registration Dates

First Submitted

September 3, 2026

First Submitted That Met QC Criteria

September 4, 2026

First Posted (Actual)

September 8, 2026

Study Record Updates

Last Update Posted (Actual)

November 4, 2026

Last Update Submitted That Met QC Criteria

November 3, 2026

Last Verified

September 11, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 10002783
  • 002783-H

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

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