P333 INFECTIVE ENDOCARDITIS ON TRICUSPID VALVE CAUSED BY S. AUREUS METHICILLIN RESPONSIVE: RESOLUTION AND RECURRENCE OF DISEASE

Abstract Introduction Tricuspid valve endocarditis accounts for 5–10% of endocarditis cases and is more frequent in intravenous drug abusers. Recurrence of endocarditis occurs not infrequently in patients treated with conservative therapy. Clinical Case In June 2021, a 32–year–old man with a history of intravenous drug abuse came to our observation. He had been presenting for about a week high fever with shaking shivering resistant to antipyretic and antibiotic therapy and laboratory tests with neutrophilic leukocytosis with increase in CRP and procalcitonin. Trans–thoracic echocardiogram was performed and it showed mild tricuspid regurgitation with the presence of filamentous mobile isoechoic formations adhering to the valve leaflets compatible with endocarditic vegetations. A trans–esophageal echocardiogram was performed that confirmed the transthoracic finding of endocarditis on the tricuspid valve with evidence of 11 mm mobile oval vegetation adhering to the posterior flap; blood cultures were positive for methicillin susceptible S. Aureus and antibiotic therapy with oxacillin was administered as a continuous infusion for 6 weeks. The cardiac surgery center was consulted and the surgeons did not indicate any intervention because of the normofunction of the tricuspid valve and the absence of embolic phenomena on total body CT. Subsequent laboratory tests showed negative inflammation indices and negative surveillance blood cultures. Control ETE was planned with the confirmation of complete resolution of endocardial lesions. In September the patient affered the emergency room for an accidental fall from a work vehicle: transthoracic and trans–esophageal echocardiograms were repeated for the concomitant finding of hyperpyrexia and cough with an increase in CRP and procalcitonin. They showed the presence of new larger endocarditic lesions on tricuspid valve with moderate regurgitation. Blood cultures were negative. Antibiotic therapy with oxacillin was reintroduced and the patient was transferred to the infectious disease clinic in prevision of cardiac surgery.