No abstract

Although the incidence of IE has not changed, important changes in disease characteristics, treatment, and outcomes were noted.

Background-The incidence of embolic events (EE) and death is still high in patients with infective endocarditis (IE), and data about predictors of these 2 major complications are conflicting. Moreover, the exact role of echocardiography in risk stratification is not well defined. Methods and Results-In a multicenter prospective European study, including 384 consecutive patients (aged 57Ϯ17 years) with definite IE according to Duke University criteria, we tested clinical, microbiological, and echocardiographic data as potential predictors of EE and 1-year mortality. Transesophageal echocardiography was performed in all patients. Embolism occurred before or after IE diagnosis (total-EE) in 131 patients (34.1%) and after initiation of antibiotic therapy (new-EE) in 28 patients (7.3%). Staphylococcus aureus and Streptococcus bovis were independently associated with total-EE, whereas vegetation length Ͼ10 mm and severe vegetation mobility were predictors of new-EE, even after adjustment for S aureus and S bovis. One-year mortality was 20.6%. In multivariable analysis, independently of the other predictors of death (age, female sex, creatinine serum Ͼ2 mg/L, moderate or severe congestive heart failure, and S aureus) and comorbidity, vegetation length Ͼ15 mm was a predictor of 1-year mortality (adjusted relative riskϭ1.

BACKGROUND. Blood culture-negative endocarditis (BCNE) may account for up to 31% of all cases of endocarditis. METHODS. We used a prospective, multimodal strategy incorporating serological, molecular, and histopathological assays to investigate specimens from 819 patients suspected of having BCNE. RESULTS. Diagnosis of endocarditis was first ruled out for 60 patients. Among 759 patients with BCNE, a causative microorganism was identified in 62.7%, and a noninfective etiology in 2.5%. Blood was the most useful specimen, providing a diagnosis for 47.7% of patients by serological analysis (mainly Q fever and Bartonella infections). Broad-range polymerase chain reaction (PCR) of blood and Bartonella-specific Western blot methods diagnosed 7 additional cases. PCR of valvular biopsies identified 109 more etiologies, mostly streptococci, Tropheryma whipplei, Bartonella species, and fungi. Primer extension enrichment reaction and autoimmunohistochemistry identified a microorganism in 5 additional patients. No virus or Chlamydia species were detected. A noninfective cause of endocarditis, particularly neoplasic or autoimmune disease, was determined by histological analysis or by searching for antinuclear antibodies in 19 (2.5%) of the patients. Our diagnostic strategy proved useful and sensitive for BCNE workup. CONCLUSIONS. We highlight the major role of zoonotic agents and the underestimated role of noninfective diseases in BCNE. We propose serological analysis for Coxiella burnetii and Bartonella species, detection of antinuclear antibodies and rheumatoid factor as first-line tests, followed by specific PCR assays for T. whipplei, Bartonella species, and fungi in blood. Broad-spectrum 16S and 18S ribosomal RNA PCR may be performed on valvular biopsies, when available.