title: Diagnosis of blood culture-negative endocarditis and clinical comparison between blood culture-negative and blood culture-positive cases.
abstract: OBJECTIVE
  To analyze the clinical characteristics of blood culture-negative endocarditis (BCNE) and how it compares to those of blood culture-positive endocarditis (BCPE) cases and show how molecular tools helped establish the etiology in BCNE.
  
  
  METHODS
  Adult patients with definite infective endocarditis (IE) and having valve surgery were included. Valves were studied by polymerase chain reaction (PCR). Statistical analysis compared BCNE and BCPE.
  
  
  RESULTS
  One hundred and thirty-one patients were included; 53 (40 %) had BCNE. The mean age was 45 ± 16 years; 33 (62 %) were male. BCNE was community-acquired in 41 (79 %). Most patients were referred from other hospitals (38, 73 %). Presentation was subacute in 34 (65 %), with fever in 47/53 (90 %) and a new regurgitant murmur in 34/42 (81 %). Native valves were affected in 74 %, mostly left-sided. All echocardiograms showed major criteria for IE. Antibiotics were used prior to BC collection in 31/42 (74 %). Definite histological diagnosis was established for 35/50 (70 %) valves. PCR showed oralis group streptococci in 21 (54 %), S. aureus in 3 (7.7 %), gallolyticus group streptococci in 2 (5.1 %), Coxiella burnetii in 1 (2.5 %) and Rhizobium sp. in 1 (2.5 %). In-hospital mortality was 9/53 (17 %). Fever (p = 0.06, OR 4.7, CI 0.91-24.38) and embolic complications (p = 0.003, OR 3.3, CI 1.55-6.82) were more frequent in BCPE cases, while new acute regurgitation (p = 0.05, OR 0.3, CI 0.098-0.996) and heart failure (p = 0.02, OR 0.3, CI 0.13-0.79) were less so.
  
  
  CONCLUSIONS
  BCNE resulted mostly from prior antibiotics and was associated with severe hemodynamic compromise. Valve histopathology and PCR were useful in confirming the diagnosis and pointing to the etiology of BCNE.
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil. cristianelamas@gmail.com.|Unigranrio, Rio de Janeiro, Brazil. cristianelamas@gmail.com.
authors.forename: Cristiane C
authors.initials: CC
authors.lastname: Lamas
authors.affiliation: Aix-Marseille Université, Marseille, France.
authors.forename: Pierre-Edouard
authors.initials: PE
authors.lastname: Fournier
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Monica
authors.initials: M
authors.lastname: Zappa
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Tatiana J D
authors.initials: TJ
authors.lastname: Brandão
authors.affiliation: Unigranrio, Rio de Janeiro, Brazil.
authors.forename: Carolina A
authors.initials: CA
authors.lastname: Januário-da-Silva
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Marcelo G
authors.initials: MG
authors.lastname: Correia
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Giovanna Ianini F
authors.initials: GI
authors.lastname: Barbosa
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Wilma F
authors.initials: WF
authors.lastname: Golebiovski
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Clara
authors.initials: C
authors.lastname: Weksler
authors.affiliation: Aix-Marseille Université, Marseille, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Lepidi
authors.affiliation: Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000328:Adult; D000071997:Blood Culture / Q000706:statistics & numerical data*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004697:Endocarditis, Bacterial / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006351:Heart Valves / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies
chemical_list: D004269:DNA, Bacterial
keywords: Diagnostic criteria; Infective endocarditis; Negative blood cultures; Polymerase chain reaction; Valve pathology