title: Heart fatty acid-binding protein in combination with the 80-lead body surface potential map improves early detection of acute myocardial infarction in patients who are cardiac troponin T-negative at presentation.
abstract: Of patients who present with ischemic-type chest pain and a negative cardiac troponin T (cTnT) at first medical contact, there are patients at a very early stage of infarction. The aim of this research was to assess heart fatty acid-binding protein (H-FABP), a novel marker of myocyte necrosis, in combination with the 80-lead body surface potential map (BSPM) in the early diagnosis of acute myocardial infarction (AMI).
  
  
  METHODS
  In this prospective study, consecutive patients presenting with acute ischemic-type chest pain between 2003 and 2006 were enrolled. At first medical contact, blood was sampled for cTnT and H-FABP; in addition, a 12-lead electrocardiogram (ECG) and BSPM were recorded. A second cTnT was sampled 12 hours or more after presentation. Peak cTnT 0.03 μg/L or higher diagnosed AMI. Elevated H-FABP was 5 ng/mL or higher. A cardiologist blinded to both the clinical details and 12-lead ECG interpreted the BSPM.
  
  
  RESULTS
  Enrolled were 407 patients (age 62 ± 13 years; 70% men). Of these 407, 180 had cTnT less than 0.03 μg/L at presentation. Acute myocardial infarction occurred in 52 (29%) of 180 patients. Of these 180 patients, 27 had ST-segment elevation (STE) on ECG, 104 had STE on BSPM (sensitivity, 88%; specificity, 55%), and 95 (53%) had H-FABP elevation. The proportion with elevated H-FABP was higher in the AMI group compared with non-AMI group (P < .001). Body surface potential map STE was significantly associated with H-FABP elevation (P < .001). Of those with initial cTnT less than 0.03 μg/L, the c-statistic for the receiver operating characteristic curve distinguishing AMI from non-AMI using H-FABP alone was 0.644 (95% confidence interval [CI], 0.521-0.771), using BSPM alone was 0.716 (95% CI, 0.638-0.793), and using the combination of BSPM and H-FABP was 0.812 (95% CI, 0.747-0.876; P < .001).
  
  
  CONCLUSIONS
  In patients with acute ischemic-type chest pain who have a normal cTnT at presentation, the combination of H-FABP and BSPM at first assessment identifies those with early AMI (c-statistic, 0.812; P < .001), thus allowing earlier triage to reperfusion therapy and secondary prevention.
authors.affiliation: The Heart Centre, Royal Victoria Hospital, Belfast, Northern Ireland, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Daly
authors.forename: Conor J
authors.initials: CJ
authors.lastname: McCann
authors.forename: Colum G
authors.initials: CG
authors.lastname: Owens
authors.forename: Mark T
authors.initials: MT
authors.lastname: Harbinson
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Adgey
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D018780:Body Surface Potential Mapping / Q000379:methods*; D016009:Chi-Square Distribution; D042241:Early Diagnosis; D004562:Electrocardiography; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis*; D011446:Prospective Studies; D012372:ROC Curve; D013997:Time Factors; D020107:Troponin T / Q000097:blood
chemical_list: D015415:Biomarkers; C493408:FABP3 protein, human; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins; D020107:Troponin T