ENTEROCOCCAL PROSTHETIC VALVE ENDOCARDITIS: A SILENT KILLER

Abstract

SESSION TITLE: Medical Student/Resident Cardiovascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Prosthetic valve endocarditis (PVE) complicates 1-6% of all valve replacements and is associated with significant mortality (1). Compared to native valve endocarditis (NVE), PVE more commonly results in paravalvular abscess (1). Enterococcal endocarditis most commonly affects the elderly and those with prosthetic valves greater than 1 year old (2). CASE PRESENTATION: A 72 year-old male presented with 1 month of fever, myalgias and headache. Medical history included atrial fibrillation and mechanical aortic valve replacement in 2009. He was afebrile with a HR of 83 bpm, BP of 135/86mmHg, normal respiratory rate and SaO2 of 97% on room air. Cardiac exam revealed an irregularly irregular rhythm, a mechanical click and no murmurs. Neurologic exam showed disequilibrium. Lab results included a WBC count of 16,800/mm³, Hgb of 12.0 g/dL, INR of 3.16 and troponin of 1.32 ng/mL. Blood cultures were positive for Enterococcus faecalis. Transthoracic echocardiogram showed a 1.2x0.7cm mobile mass on the mechanical aortic valve without evidence of paravalvular complication. MRI brain showed cerebellar ischemia due to septic emboli. He was started on vancomycin and ceftriaxone. In an effort to rule out gastrointestinal (GI) malignancy or abscess, CT abdomen/pelvis was completed and normal. On hospital day 4, he had an 11-second pause requiring a transvenous pacemaker. On day 5, he went to the operating room for mechanical valve extraction and replacement and was found to have a subvalvular aortic abscess with a necrotic aortic root. He was unable to be weaned from cardiopulmonary bypass and died in the operating room. DISCUSSION: Enterococcal PVE is associated with increased risk of periprosthetic dehiscence and abscess (2). Studies have suggested that early surgical intervention should be considered in Enterococcal PVE due to the high likelihood of paravalvular complications (2,3). Echocardiography is less likely to detect paravalvular complications in PVE compared to NVE (3). Further data is needed to determine if GI lesions should be ruled out prior to intervention. Enterococcal PVE can have a subtle and subacute presentation but with catastrophic complications, such as seen in our case. These complications can be missed by echocardiography, resulting in delayed diagnosis and treatment. CONCLUSIONS: An early surgical approach should be considered for all patients with Enterococcal PVE. Paravalvular complications of PVE are often missed by echocardiography alone. Assessing for GI source of infection can delay intervention. Patients with prosthetic valves should be reminded that even minor symptoms can represent serious and life-threatening infection. Reference #1: Habib, G., et al. “Prosthetic Valve Endocarditis: Current Approach and Therapeutic Options.” Progress in Cardiovascular Diseases, vol. 50, no. 4, 2008, pp. 274–281. Reference #2: Chirouze, C., et al. “Enterococcal Endocarditis in the Beginning of the 21st Century: Analysis from the International Collaboration on Endocarditis-Prospective Cohort Study.” Clinical Microbiology and Infection, vol. 19, 2013, pp. 1140–1147. Reference #3: Nataloni, M., et al. “Prosthetic Valve Endocarditis.” Journal of Cardiovascular Medicine , vol. 11, 18 Dec. 2009, pp. 869–883. DISCLOSURES: No relevant relationships by Nayrana Griffith, source=Web Response No relevant relationships by James Lawrence, source=Web Response No relevant relationships by Patrick Miller, source=Web Response No relevant relationships by Andrew Stevens, source=Web Response