title: Multimarker panel to rule out acute coronary syndromes in low-risk patients.
abstract: OBJECTIVE
  To test novel markers of acute coronary syndrome (ACS), monocyte chemoattractant protein-1 (MCP), myeloperoxidase (MPO), C-reactive protein (CRP), and brain natriuretic peptide (BNP) in low-risk emergency department (ED) patients who were evaluated for ACS in a chest pain unit (CPU).
  
  
  METHODS
  A convenience sample of 414 patients underwent CPU evaluation, including provocative testing, and were followed prospectively for 45 days for ACS, which was defined as death, myocardial infarction (MI), revascularization, or >60% coronary artery stenosis prompting new medical treatment, adjudicated by three blinded reviewers. Published diagnostic thresholds were used to calculate diagnostic indices for each marker and for the multimarker panel.
  
  
  RESULTS
  The prevalence of ACS was 7 in 414 (1.7%; 95% CI = 0.7% to 3.5%). Only MCP demonstrated a negative likelihood ratio [LR(-)] of less than 0.5, with a sensitivity of 85% (95% CI = 42% to 99%), specificity of 72% (95% CI = 67% to 76%), and LR(-) of 0.20 (95% CI = 0.04 to 0.71). For MPO, CRP, and BNP, LR(-) was 0.89 (95% CI = 0.26 to 2.05), 0.79 (95% CI = 0.40 to 1.01), and 0.90 (95% CI = 0.51 to 1.03), respectively. The sensitivity, specificity, and LR(-) of an abnormal multimarker panel were 86% (95% CI = 42% to 100%), 17% (95% CI = 13% to 21%), and 0.84 (95% CI = 0.15 to 3.12), respectively.
  
  
  CONCLUSIONS
  The prevalence of ACS was very low but was similar to reports from other CPUs. BNP and CRP had high specificities, but had limited sensitivities, whereas MPO had a low specificity. Only MCP had a low LR(-) and should be studied further. The combined multimarker panel had an unexpectedly low sensitivity and specificity, yielding an LR(-) of 0.84, suggesting that the panel would not be an efficient screening test to decrease unnecessary CPU testing.
authors.affiliation: Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC 28323-2861, USA.
authors.forename: Alice M
authors.initials: AM
authors.lastname: Mitchell
authors.forename: Joseph Lee
authors.initials: JL
authors.lastname: Garvey
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kline
mesh_terms: D000208:Acute Disease; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D018932:Chemokine CCL2 / Q000097:blood; D003327:Coronary Disease / Q000097:blood* / Q000175:diagnosis*; D006801:Humans; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis; D020097:Natriuretic Peptide, Brain / Q000097:blood; D009195:Peroxidase / Q000097:blood; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D018932:Chemokine CCL2; D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D009195:Peroxidase