Staphylococcus lugdunensis infective endocarditis with perforation of the sinus of Valsalva: a case report

Background Staphylococcus lugdunensis endocarditis is a rare but fulminant disease. Case summary A 74-year-old female with a history of asymptomatic severe aortic valve stenosis and permanent atrial fibrillation presented with acute onset of fever (39.0°C). Electrocardiogram showed diffuse ST-segment elevation. She was hospitalized for further analysis. All blood cultures were positive for Staphylococcus lugdunensis and antibiotic treatment was started. Transthoracic echocardiography (TTE) showed known aortic valve stenosis without clear signs of endocarditis. The following day, a transoesophageal echocardiogram (TEE) showed a new moderate aortic valve regurgitation, new pericardial effusion (PE), and a thickened sinus of Valsalva (SOV) consistent with endocarditis with paravalvular involvement. Positron emission tomography-computed tomography was consistent with aortic valve endocarditis with paravalvular expansion. The patient was transferred to a tertiary referral centre for surgical treatment. On admission, patient was in shock and a second TTE revealed a new systolic and diastolic flow through the SOV to the right ventricle indicating SOV perforation. Additionally, there was flow in the PE suggestive of perforation of one of the cardiac chambers or large vessels. Emergent surgery showed extended infection with SOV perforation and a large perforation of the right ventricle. Ultimately, patient died during the operation because of extensive infection and refractory shock. Conclusion Staphylococcus lugdunensis endocarditis is a severe disease with poor response to conventional anti-microbial treatment, destructive complications requiring surgery, and has a high mortality risk.