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.