Isolated Enterococcus faecalis pulmonary valve endocarditis without precipitating risk factors: A case report describing delayed need for surgery three years after antimicrobial therapy.

INTRODUCTION AND IMPORTANCE: Isolated Enterococcus faecalis pulmonary valve endocarditis (PVE) without precipitating risk factors is exceeding rare, as fewer than ten cases have been published in the literature, most of which did not require surgical intervention. CASE PRESENTATION: An elderly individual presented for evaluation of dyspnea, fatigue, dizziness, weight loss, and a low-grade fever. The patient denied intravenous drug abuse, blood-borne viral infection, cardiac trauma, congenital heart disease, and immunocompromise. Echocardiography identified a large vegetation on the right pulmonary valve leaflet consistent with isolated PVE. Blood cultures grew E. faecalis. Computed tomography failed to reveal an infectious source. The patient completed a six-week course of antibiotics and was followed with serial echocardiography for three years, but subsequently developed severe pulmonic insufficiency and right heart failure necessitating pulmonary valve replacement. CLINICAL DISCUSSION: Isolated PVE is responsible for less than 2.0% of all cases of infective endocarditis. The vast majority of reported cases are associated with risk factors and are caused by gram-positive organisms including Staphylococcus species and Streptococcus viridans. Echocardiography identifies most cases of isolated PVE. Septic embolization of vegetation fragments to lung parenchyma is common. Surgery is reserved for patients who are unresponsive to antibiotics or those who develop severe pulmonary insufficiency with symptoms of right heart failure, as seen here. CONCLUSION: We present an unusual case of isolated E. faecalis PVE without known risk factors that required pulmonary valve replacement three years after antimicrobial therapy.