Intra Coronary Pus Excretion Without Cardiac Abscess Formation as a Manifestation of Acute Culture Negative Endocarditis Associated With Acute Coronary Syndrome: A Rare Presentation

Abstract

This case report describes a 27-year-old male intravenous cannabis user who presented with a week-long history of fever and dyspnea on exertion, subsequently developing typical chest pain in the last two days. Upon admission, the patient exhibited febrile tachycardia, pale and cold extremities, and a systolic murmur at the left sternal border. Laboratory findings included significantly elevated CRP, ESR, thyroid-stimulating hormone, and liver enzyme levels, alongside leukocytosis, anemia, hyperglycemia, hyponatremia, abnormal renal function tests, suspected anti-HCV antibody, and elevated cardiac troponins. Echocardiography revealed moderate left ventricular enlargement with severe systolic dysfunction, moderate right ventricular dysfunction, severe left atrial and mild right atrial enlargement, and a thickened, prolapsed bileaflet mitral valve with a large mobile mass on the atrial surface of the anterior mitral leaflet. The condition led to severe acute mitral regurgitation. Additional findings included moderate tricuspid regurgitation, moderate pulmonary arterial hypertension, mild circumferential pericardial effusion, and significant bilateral pleural effusion. Despite these findings, blood cultures were negative, suggesting culture-negative endocarditis. Elevated cardiac troponin levels and Q wave formation on septal leads warranted angiography, which revealed a cut-off first septal artery. The patient underwent mitral valve replacement and coronary artery bypass grafting, during which intracoronary pus excretion under high pressure was observed, indicating septic embolization to the coronary arteries. This case highlights the rare mechanism of acute coronary syndrome development through septic embolization in the setting of culture-negative acute endocarditis. © 2026 Tehran University of Medical Sciences.