title: Heart valve culture and sequencing to identify the infective endocarditis pathogen in surgically treated patients.
abstract: BACKGROUND
  Testing excised valves in surgically treated infective endocarditis (IE) patients provides an opportunity to identify the microbial etiology of IE. Microbial sequencing (universal bacterial, mycobacterial, or fungal polymerase chain reaction followed by DNA sequencing) of valves can identify microorganisms accurately, but the value it adds beyond information provided by blood and valve cultures has not been adequately explored.
  
  
  METHODS
  Three hundred fifty-six patients who underwent surgery for active IE from January 1, 2010, to January 1, 2013, were identified from our cardiovascular information registry and outpatient parenteral antibiotic therapy registry. Their records were reviewed to identify 174 patients whose valves were sent for sequencing. The microbial etiology of IE was defined using comprehensive clinical, pathologic, and microbiological criteria. Blood culture, valve culture, and valve sequencing were examined to determine how frequently they identified the definitive cause of IE.
  
  
  RESULTS
  Of the 174 patients, 162 (93%) had acute inflammation on histopathologic examination of their valves. Valve sequencing was significantly more sensitive than valve culture in identifying the causative pathogen (90% versus 31%, p < 0.001), and yielded fewer false positive results (3% versus 33%, p <0.001). The pathogen would not have been identified in 25 patients (15%) had it not been for valve sequencing. All the value provided by sequencing was attributable to bacterial DNA sequencing; mycobacterial and fungal sequencing provided no additional information beyond that provided by blood culture, histopathology, and valve culture.
  
  
  CONCLUSIONS
  Valve sequencing, not valve culture, should be considered the primary test for identifying bacteria in excised cardiac valves.
authors.affiliation: Department of Infectious Disease, Cleveland Clinic, Cleveland, Ohio; Department of Clinical Pathology, Cleveland Clinic, Cleveland, Ohio. Electronic address: shrestn@ccf.org.
authors.forename: Nabin K
authors.initials: NK
authors.lastname: Shrestha
authors.affiliation: Department of Infectious Disease, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Ledtke
authors.affiliation: Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Hannah
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Infectious Disease, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Fraser
authors.affiliation: Department of Infectious Disease, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Rehm
authors.affiliation: Department of Cardiothoracic Surgery, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Syed T
authors.initials: ST
authors.lastname: Hussain
authors.affiliation: Department of Cardiothoracic Surgery, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Gosta B
authors.initials: GB
authors.lastname: Pettersson
authors.affiliation: Department of Cardiothoracic Surgery, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.affiliation: Department of Infectious Disease, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Gordon
mesh_terms: D004696:Endocarditis / Q000382:microbiology* / Q000601:surgery*; D006351:Heart Valves / Q000382:microbiology*; D006801:Humans; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies