Background-Myocardial infarct expansion and left ventricular (LV) remodeling are integral components in the evolution of chronic heart failure and predict morbidity and mortality. Radiofrequency (RF) heating and patch placement of chronic LV aneurysms caused a sustained reduction in LV infarct area and volume in an ovine infarct model. This study evaluated the effect of RF heating and epicardial patch as an adjunct to coronary artery bypass graft on LV volumes in patients with prior myocardial infarction, evidence of akinetic/dyskinetic scar, and LV ejection fraction Յ40%. Methods and Results-Ten patients (3 female; mean age, 64Ϯ11 years) scheduled for coronary artery bypass graft were enrolled (Canadian Cardiovascular Society angina class 2.1Ϯ1.1; New York Heart Association class 3.1Ϯ0.5).Intraoperative digital photography demonstrated an acute 39% reduction in infarct area (nϭ5; Pϭ0.01), and transesophageal ECGs demonstrated a 16% acute reduction in LV end-diastolic volumes (nϭ9; Pϭ0.002) after RF treatment. There were no intraoperative or procedure-related postoperative complications, and during an average follow-up of Ͼ180 days, there have been no safety issues. All patients had complete relief of their angina and improvement in exercise tolerance. Serial transthoracic ECGs over the 6 months of follow-up after RF treatment demonstrated persistent reductions in LV end-diastolic volume (29%; PϽ0.0001) and LV end-systolic volume (37%; PϽ0.0001) with improved ejection fraction (PϽ0.02). Conclusions-RF heating and patch placement in these 10 patients resulted in acute reduction in infarct area and ventricular volumes that were maintained 180 days after procedure. This technique may reduce the incidence of congestive heart failure and mortality in these patients and warrants investigation in larger clinical trials. (Circulation.