[Endocarditis caused by Propionibacterium acnes -- a diagnostic and therapeutic challenge].

HISTORY AND ADMISSION FINDINGS

A 77-year-old man suffered from recurrent peripheral cerebral embolisms five months after aortic valve replacement with a bioprosthesis (SJM Epic 25 mm).

INVESTIGATIONS

MRT scanning of the brain revealed multiple ischemic areas in different vascular territories. Clinical signs of infective endocarditis were missing and markers of infection were only modestly increased. However, transthoracic echocardiography showed elevated pressure gradients across the bioprosthesis. Transesophageal echocardiography detected multiple vegetations suggestive of infective endocarditis. Several anaerobic blood cultures grew Propionibacterium acnes.

DIAGNOSIS, TREATMENT AND COURSE: Infective endocarditis affecting the aortic bioprosthesis and aortic root abscess due to Propionibacterium acnes was diagnosed. During parenteral antibiotic treatment with Amicillin/Sulbactam and Gentamicin full remission developed. Four months later a follow-up transesophageal echocardiography showed a relapse. This time the patient was treated intravenously with penicillin and gentamicin and underwent surgical treatment.

CONCLUSION

Cardioembolic events should raise suspicion of infective endocarditis, even if typical clinical signs are absent. Propionibacterium acnes is often grown from blood cultures as a contaminant. Nonetheless, Propionibacterium acnes was the cause of the infective endocarditis. In case of conservative management, close intervals of follow-up transesphageal echocardiography are of importance.