title: Diagnosing Acute Heart Failure in the Emergency Department: A Systematic Review and Meta-analysis.
abstract: BACKGROUND
  Acute heart failure (AHF) is one of the most common diagnoses assigned to emergency department (ED) patients who are hospitalized. Despite its high prevalence in the emergency setting, the diagnosis of AHF in ED patients with undifferentiated dyspnea can be challenging.
  
  
  OBJECTIVE
  The primary objective of this study was to perform a systematic review and meta-analysis of the operating characteristics of diagnostic elements available to the emergency physician for diagnosing AHF. Secondary objectives were to develop a test-treatment threshold model and to calculate interval likelihood ratios (LRs) for natriuretic peptides (NPs) by pooling patient-level results.
  
  
  METHODS
  PubMed, EMBASE, and selected bibliographies were searched from January 1965 to March 2015 using MeSH terms to address the ability of the following index tests to predict AHF as a cause of dyspnea in adult patients in the ED: history and physical examination, electrocardiogram, chest radiograph (CXR), B-type natriuretic peptide (BNP), N-terminal proB-type natriuretic peptide (NT-proBNP), lung ultrasound (US), bedside echocardiography, and bioimpedance. A diagnosis of AHF based on clinical data combined with objective test results served as the criterion standard diagnosis. Data were analyzed using Meta-DiSc software. Authors of all NP studies were contacted to obtain patient-level data. The Quality Assessment Tool for Diagnostic Accuracy Studies-2 (QUADAS-2) for systematic reviews was utilized to evaluate the quality and applicability of the studies included.
  
  
  RESULTS
  Based on the included studies, the prevalence of AHF ranged from 29% to 79%. Index tests with pooled positive LRs ≥ 4 were the auscultation of S3 on physical examination (4.0, 95% confidence interval [CI] = 2.7 to 5.9), pulmonary edema on both CXR (4.8, 95% CI = 3.6 to 6.4) and lung US (7.4, 95% CI = 4.2 to 12.8), and reduced ejection fraction observed on bedside echocardiogram (4.1, 95% CI = 2.4 to 7.2). Tests with low negative LRs were BNP < 100 pg/mL (0.11, 95% CI = 0.07 to 0.16), NT-proBNP < 300 pg/mL (0.09, 95% CI = 0.03 to 0.34), and B-line pattern on lung US LR (0.16, 95% CI = 0.05 to 0.51). Interval LRs of BNP concentrations at the low end of "positive" results as defined by a cutoff of 100 pg/mL were substantially lower (100 to 200 pg/mL; 0.29, 95% CI = 0.23 to 0.38) than those associated with higher BNP concentrations (1000 to 1500 pg/mL; 7.12, 95% CI = 4.53 to 11.18). The interval LR of NT-proBNP concentrations even at very high values (30,000 to 200,000 pg/mL) was 3.30 (95% CI = 2.05 to 5.31).
  
  
  CONCLUSIONS
  Bedside lung US and echocardiography appear to the most useful tests for affirming the presence of AHF while NPs are valuable in excluding the diagnosis.
authors.affiliation: The Department of Emergency Medicine, SUNY Downstate Medical Center, New York, NY.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Martindale
authors.affiliation: The Emergency Care Research Unit, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Abel
authors.initials: A
authors.lastname: Wakai
authors.affiliation: The Department of Emergency Medicine, Vanderbilt University, Nashville, TN.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Collins
authors.affiliation: The Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, MI.
authors.forename: Phillip D
authors.initials: PD
authors.lastname: Levy
authors.affiliation: The Department of Emergency Medicine, University of Texas Southwestern, Dallas, TX.
authors.forename: Deborah
authors.initials: D
authors.lastname: Diercks
authors.affiliation: The Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Hiestand
authors.affiliation: The Department of Emergency Medicine, University of Cincinnati, Cincinnati, OH.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Fermann
authors.affiliation: The Department of Emergency Medicine, SUNY Downstate Medical Center, New York, NY.
authors.forename: Ian
authors.initials: I
authors.lastname: deSouza
authors.affiliation: The Department of Emergency Medicine, SUNY Downstate Medical Center, New York, NY.|The Emergency Care Research Unit, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Richard
authors.initials: R
authors.lastname: Sinert
mesh_terms: D000208:Acute Disease; D003937:Diagnosis, Differential; D004417:Dyspnea / Q000209:etiology; D004452:Echocardiography; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D010808:Physical Examination / Q000379:methods; D013902:Radiography, Thoracic
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain