title: An Approach to Improve the Negative Predictive Value and Clinical Utility of Transthoracic Echocardiography in Suspected Native Valve Infective Endocarditis.
abstract: BACKGROUND
  In patients with suspected native valve infective endocarditis, current guidelines recommend initial transthoracic echocardiography (TTE) followed by transesophageal echocardiography (TEE) if clinical suspicion remains. The guidelines do not account for the quality of initial TTE or other findings that may alter the study's diagnostic characteristics. This may lead to unnecessary TEE when initial TTE was sufficient to rule out vegetation.
  
  
  METHODS
  The objective of this study was to determine if the use of a strict definition of negative results on TTE would improve the performance characteristics of TTE sufficiently to exclude vegetation. A retrospective analysis of patients at a single institution with suspected native valve endocarditis who underwent TTE followed by TEE within 7 days between January 1, 2007, and February 28, 2014, was performed. Negative results on TTE for vegetation were defined by either the standard approach (no evidence of vegetation seen on TTE) or by applying a set of strict negative criteria incorporating other findings on TTE. Using TEE as the gold standard for the presence of vegetation, the diagnostic performance of the two transthoracic approaches was compared.
  
  
  RESULTS
  In total, 790 pairs of TTE and TEE were identified. With the standard approach, 661 of the transthoracic studies had negative findings (no vegetation seen), compared with 104 studies with negative findings using the strict negative approach (meeting all strict negative criteria). The sensitivity and negative predictive value of TTE for detecting vegetation were substantially improved using the strict negative approach (sensitivity, 98% [95% CI, 95%-99%] vs 43% [95% CI, 36%-51%]; negative predictive value, 97% [95% CI, 92%-99%] vs 87% [95% CI, 84%-89%]).
  
  
  CONCLUSIONS
  The ability of TTE to exclude vegetation in patients is excellent when strict criteria for negative results are applied. In patients at low to intermediate risk with strict negative results on TTE, follow-up TEE may be unnecessary.
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors: Joseph A
authors: JA
authors: Sivak
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina; Duke Clinical Research Institute, Durham, North Carolina.
authors: Amit N
authors: AN
authors: Vora
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors: Ann Marie
authors: AM
authors: Navar
authors: Duke Clinical Research Institute, Durham, North Carolina.
authors: Phillip J
authors: PJ
authors: Schulte
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors: Anna Lisa
authors: AL
authors: Crowley
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors: Joseph
authors: J
authors: Kisslo
authors: Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina; Duke Clinical Research Institute, Durham, North Carolina.
authors: G Ralph
authors: GR
authors: Corey
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors: Lawrence
authors: L
authors: Liao
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors: Andrew
authors: A
authors: Wang
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina; Duke Clinical Research Institute, Durham, North Carolina.
authors: Eric J
authors: EJ
authors: Velazquez
authors: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina. Electronic address: zainab.samad@dm.duke.edu.
authors: Zainab
authors: Z
authors: Samad
mesh_terms: D004452:Echocardiography / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods; D004697:Endocarditis, Bacterial / Q000150:complications / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000175:diagnosis* / Q000209:etiology; D006351:Heart Valves / Q000000981:diagnostic imaging*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors
keywords: Echocardiography; Infective endocarditis; Screening; Transesophageal echocardiography