Abstract

Context: Early prosthetic valve endocarditis is a deadly disease and blood cultures remain negative in 14% to 30% of cases.

Objectives: To analyze the clinical and microbiological profile of patients with blood culture negative early prosthetic valve endocarditis (“BCN early PVE”) in order to define the most appropriate empiric treatment.

Design, setting and participants: From June 2001 to February 2009, a prospective multimodal strategy incorporating serological, molecular and histopathological assays was performed in all the samples referred to our laboratory for a suspicion of blood culture negative endocarditis from France and abroad (n=718). A total of 31 patients with “BCN early PVE” were identified. Their microbiological profile was compared with that of 22 patients with blood culture positive early prosthetic valve endocarditis (“PBC early PVE”) and 628 patients with “Community-acquired BCNE” identified during the same period.

Results: A pathogen was identified in 10 patients (32%) with “BCN early PVE”. Fungi were the most common pathogens identified being found in 16% versus 4.5% in case of “PBC early PVE” and 0.5% in “Community-acquired BCNE” (p<0.0001). The global microbiological profile of “BCN early PVE” differed strongly from that of “PBC early PVE” and “Community-acquired BCNE”. A higher rate of microbiological diagnosis was obtained in patients who underwent surgery (9/21 [43%] versus 1/10 [10%], p=0.07) and an increased rate of recurrences was observed when a pathogen could not be identified (9/21 [43%] versus 1/10 [10%], p=0.07).

Conclusions: “BCN early PVE” exhibit specific aetiologies as fungi are the most frequent pathogens identified. Therefore, we suggest investigating fungi particularly by molecular methods on surgical specimen and that an antifungal drug might be added to the empiric treatment.