Abstract 14459: Case Report: Unusual Presentation of Cardiobacterium Hominis Bioprosthetic Valve Endocarditis

Abstract

Introduction: Cardiobacterium hominis , part of the oropharyngeal flora, is a gram-negative bacteria reported to cause infection in less than 5% of patients with infective endocarditis (IE). In children, congenital heart disease (CHD) is a predominant risk factor for developing IE. Herein we describe an unusual presentation of C. hominis bioprosthetic valve endocarditis. Case Presentation: A 23-year-old woman with bicuspid aortic valve and aortic valve stenosis underwent aortic bioprosthetic valve placement in 2017. In March 2022, she presented to an emergency room with left lower abdominal pain. A CT scan demonstrated occlusion of the left iliac artery. Medications at that time included oral contraceptive pills and baby aspirin. No echocardiogram was obtained at that visit. She presented for a routine cardiology follow-up in May 2022 at which time she was asymptomatic. Transthoracic echocardiogram demonstrated moderate to severe aortic insufficiency, though the mechanism could not be delineated. There was concomitant development of mild mitral valve and tricuspid valve insufficiency. She denied dyspnea, chest pain, or fevers. Laboratory investigation showed mild elevation of CRP and a normal ESR. A transesophageal echocardiogram demonstrated that the severe aortic regurgitation was through a paravalvar leak (figure 1). There was no evidence of vegetations. Three separate blood cultures grew C. hominis . The patient was admitted for IV antibiotic therapy prior to bioprosthetic replacement. Conclusions: C. hominis is an infrequent cause of endocarditis and most cases present with fever and elevated ESR. This patient had an unusual presentation with left iliac thrombus, which in retrospect was likely due to embolism of a vegetation. She also developed aortic bioprosthetic paravalvar leak. This case highlights the need for a high degree of suspicion for endocarditis in patients with CHD and bioprosthetic valves.