feasibility study of radiofrequency heating of cardiac infarction scar to treat heart failure

Conditions: Heart Failure

Summary: the purpose of this study is to examine the safety and potential effectiveness of a new surgical procedure for treating heart failure. the experimental treatment is performed during standard coronary artery bypass graft (cabg) surgery, and applies radiofrequency energy to heat a portion of the damaged heart muscle. the tissue heating reduces the enlarged heart of patients suffering from ischemic heart failure, and may result in the heart pumping blood more efficiently, thereby improving the functional status of the patient.

heart failure is an important health-care problem, resulting in significant numbers of patients, hospitalizations, and economic costs. the etiology of heart failure is coronary artery disease in approximately two-thirds of cases, and the majority of these patients have experienced prior myocardial infarction. as a consequence of the myocardial infarction, the ventricle undergoes changes in volume and shape, a process referred to as "ventricular remodeling". as the left ventricle enlarges, global systolic function worsens, resulting in heart failure. there are a number of treatment options available to minimize symptoms and somewhat slow disease progression. unfortunately, even with best conventional drug and device therapies, heart failure patients continue to have high morbidity and mortality rates. the experimental therapy investigated in this study uses a surgical device which employs radiofrequency energy to heat epicardial tissue. the application of heat to a myocardial infarction scar causes it to shrink in size, and correspondingly reduces ventricular volume. the volume reduction may "reverse remodel" the enlarged and dysfunctioning left ventricle to a more normal size and shape. the intent of this clinical study is to evaluate whether radiofrequency heating of the myocardial infarct scar is safe, and determine if the resulting ventricular volume reduction translates into improved clinical and functional outcomes in patients suffering from ischemic heart failure.

Eligibility criteria:
inclusion criteria: * age 18 to 80 years, inclusive * symptomatic heart failure (defined as persistent nyha class ii or iii during the 3 months prior to enrollment) * on evidence-based medical therapy for heart failure during the 1 month prior to enrollment * referred for elective coronary artery bypass grafting * dyskinetic transmural myocardial infarct located in the apical portion of the anterior, lateral, and/or inferior left ventricular wall as determined by transthoracic echocardiography ("transmural" means end-diastolic wall thickness of 4 - 6 mm, inclusive) * left ventricular ejection fraction 20 - 45%, inclusive as determined by transthoracic echocardiography * left ventricular end-systolic volume index ≥ 60 ml/m2 as determined by transthoracic echocardiography * 6-minute walk distance over 150 m * peak vo2 (ml/kg/min): 10.0 - 20.0 for males and 9.0 - 18.0 for females exclusion criteria: * myocardial infarction ≤ 3 months prior to enrollment * evidence of calcification within the scar intended to be treated by any imaging modality * presence of a coronary stent within the scar intended to be treated * evidence of left ventricular thrombus * emergent cardiac surgery * percutaneous coronary intervention (pci) ≤ 1 month prior to enrollment or planned following enrollment * only for patients undergoing mr (rather than ct) imaging: contraindications for mri (current or anticipated during the 6 months following enrollment), such as pacemaker, automatic implantable cardioverter-defibrillator (aicd), cardiac resynchronization therapy (crt) device, central nervous system aneurysm clips, cochlear implant, or metal shrapnel * only for patients undergoing mr (rather than ct) imaging: acute or chronic severe renal insufficiency (i.e. a glomerular filtration rate \< 30 ml/min/1.73m2) or acute renal insufficiency of any severity due to hepato-renal syndrome * only for patients undergoing mr (rather than ct) imaging: known allergy or reaction to gadolinium * atrial fibrillation * prior cardiac surgery (including coronary artery bypass grafting, valve replacement or repair, aortic root replacement) or anticipated during the 6 months following enrollment * major non-cardiac surgery (e.g. knee or hip replacement, laparotomy, carotid endarterectomy, etc.) ≤ 3 months prior to enrollment or planned during the 6 months following enrollment * prior heart, kidney, liver, or lung transplantation * valvular heart disease requiring replacement or repair (e.g. mitral valve regurgitation ≥ 3+) * cardiogenic shock ≤ 72 hours prior to the cabg surgery (defined as need for intra-aortic balloon pump or requiring intravenous inotropic support) * currently needing (or anticipated need for) left ventricular assist device or other cardiac replacement device * on active heart transplant list or anticipated need for transplant during the 6 months following enrollment * stoke or transient ischemic attack ≤ 3 months prior to enrollment * chronic dialysis * major infection or sepsis ≤ 72 hours of enrollment (defined as requiring iv antibiotics for \> 3 days) * endocarditis, myocarditis, or pericarditis * co-morbid condition that, in the investigator's opinion, results in the patient's life expectancy being \< 180 days * evidence of significant blood chemistry abnormalities, including creatinine \> 2.5 mg/dl, bun ≥ 100 mg/dl, liver function tests \> 3 times upper limit of normal, hgb \ 20,000/mm3 * females of child-bearing potential without a documented negative pregnancy test within the 14 days prior to enrollment (and prior to the mri or ct) or who are unwilling to use effective contraception for the duration of this study * participation in another investigational device or drug trial * unable or unwilling to give informed consent * unwilling or unlikely to complete the required follow-up * any other medical condition that, in the judgment of the investigator, would cause this study to be detrimental to the patient

Keywords: heart failure cardiomyopathy ventricular dysfunction heart disease