Infective endocarditis without biological inflammatory syndrome: Description of a particular entity.

BACKGROUND: Bacterial infective endocarditis (IE) is rarely suspected in patients with a low C-reactive protein (CRP) concentration. AIMS: To address the incidence, characteristics and outcome of left-sided valvular IE with low CRP concentration. METHODS: This was a retrospective analysis of cases of IE discharged from our institution between January 2009 and May 2017. The 10% lowest CRP concentration (<20mg/L) was used to define low CRP concentration. Right-sided cardiac device-related IE, non-bacterial IE, sequelar IE and IE previously treated by antibiotics were excluded. RESULTS: Of the 469 patients, 13 (2.8%; median age 68 [61-76] years) had definite (n=8) or possible (n=5) left-sided valvular IE with CRP<20mg/L (median 9.3 [4.7-14.2] mg/L). The median white blood cell count was 6.3 (5.3-7.5) G/L. The main presentations were heart failure (n=7; 54%) and stroke (n=3; 23%). Transthoracic echocardiography (TTE) showed vegetations (n=5) or isolated valvular regurgitation (n=4). Overall, eight patients (62%) had severe valvular lesions on transoesophageal echocardiography (TOE), and nine patients (69%) underwent cardiac surgery. All patients survived at 1-year follow-up. Bacterial pathogens were documented in eight patients (streptococci, coagulase-negative Staphylococcus, Corynebacteriumjeikeium, HACEK group, Coxiella burnetii, Bartonella henselae) using blood cultures, serology or valve culture and/or polymerase chain reaction analysis. CONCLUSIONS: Left-sided valvular IE with limited or no biological syndrome is rare, but is often associated with severe valvular and paravalvular lesions. TOE should be performed in presence of unexplained heart failure, new valvular regurgitation or cardioembolic stroke when TTE is insufficient to rule out endocarditis, even in patients with a low CRP concentration.

Prognostic Value of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Infective Endocarditis.

BACKGROUND: 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is commonly used for the diagnosis of infective endocarditis (IE), but its prognostic value remains unknown. OBJECTIVES: This study sought to assess the prognostic value of 18F-FDG PET/CT in prosthetic valve endocarditis (PVE) and native valve endocarditis (NVE). METHODS: This study prospectively included 173 consecutive patients (109 PVE and 64 NVE) with definite left-sided IE who had an 18F-FDG PET/CT and were followed-up for 1 year. The primary endpoint was a composite of major cardiac events: death, recurrence of IE, acute cardiac failure, nonscheduled hospitalization for cardiovascular indication, and new embolic event. RESULTS: 18F-FDG PET/CT was positive in 100 (58%) patients, 83% (n = 90 of 109) in the PVE, and 16% (n = 10 of 64) in the NVE group. At a mean follow-up of 225 days (interquartile range: 199 to 251 days), the primary endpoint occurred in 94 (54%) patients: 63 (58%) in the PVE group and 31 (48%) in the NVE group. In the PVE group, positive 18F-FDG PET/CT was significantly associated with a higher rate of primary endpoint (hazard ratio [HR]: 2.7; 95% confidence interval [CI]: 1.1 to 6.7; p = 0.04). Moderate to intense 18F-FDG valvular uptake was also associated with worse outcome (HR: 2.3; 95% CI: 1.3 to 4.5; p = 0.03) and to new embolic events in PVE (HR: 7.5; 95% CI: 1.24 to 45.2; p = 0.03) and in NVE (HR: 8.8; 95% CI: 1.1 to 69.5; p = 0.02). In the NVE group, 18F-FDG PET/CT was not associated with occurrence of the primary endpoint CONCLUSIONS: In addition to its good diagnostic performance, 18F-FDG PET/CT is predictive of major cardiac events in PVE and new embolic events within the first year following IE.