A case of a 49-year-old man with a history of buprenorphine-substituted heroin was admitted for acute heart failure after three months of bioprosthetic aortic replacement to treat infective endocarditis. Transthoracic echocardiography (TTE) showed a left ventricular ejection fraction (EF) was 35% and a periprosthetic mass with an aorto-ventricular fistula. Thoracic computed tomography revealed a left ventricular outflow tract (LVOT) pseudoaneurysm measuring 69 x 45 mm that compressed left anterior descending (LAD) artery with downstream myocardial ischemia. Patient was treated by an urgent surgery, including an exclusion of the pseudoaneurysm, a left ventricular reconstruction surgery and a bioprosthetic aortic replacement. Patient went through a difficult postoperative period. Finally, he was safely discharged with a low EF (34%) from hospital to rehabilitation center with a Life vest. This case spotlights a rare devastating complication of a LVOT pseudoaneurysm compresses LAD artery and how surgery could decompress the false aneurysm and stabilize ischemia.