An interventional study of SESAME Procedure in Hypertrophic Cardiomyopathy, Left Ventricular Outflow Obstruction and Systolic Anterior Motion, sponsored by National Heart, Lung, and Blood Institute (NHLBI). Not yet recruiting at 8 sites in United States. Open to participants aged 21 Years to 100 Years. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by National Heart, Lung, and Blood Institute (NHLBI) · Not applicable, Interventional, and Treatment
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.
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.
363 studies on the registry are indexed under Cardiomyopathy, Hypertrophic; 116 are open to participants now.
This study's planned enrollment of 200 is above the median of 60 across 180 interventional studies indexed under Cardiomyopathy, Hypertrophic.
Browse Cardiomyopathy, Hypertrophic studies →National Heart, Lung, and Blood Institute (NHLBI) is the lead sponsor of 1,143 studies on the registry; 71 are open to participants now.
Of its 58 completed or terminated interventional studies of FDA-regulated products, 51 (88%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Requires left ventricular septal reduction therapy for one of two indications
Septal diastolic thickness on CT as measured by the NHLBI central laboratory before enrollment:
and
Intended minimum diastolic residual septal thickness >=6mm
-Severely symptomatic, any of
Canadian Angina Class CCS III or greater
Explicitly chooses SESAME over conventional treatment approaches including
EXCLUSION CRITERIA
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The intervention is the SESAME procedure.
Device: 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.
SESAME Technical Success
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%.
Time frame: Completion of SESAME procedure
SESAME Safety
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.
Time frame: 30 days after SESAME procedure
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Cardiomyopathy, Hypertrophic →
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