title: Diagnostic evaluation of the MRP-8/14 for the emergency assessment of chest pain.
abstract: Elevated levels of myeloid-related protein (MRP)-8/14 (S100A8/A9) are associated with first cardiovascular events in healthy individuals and worse prognosis in patients with acute coronary syndrome (ACS). The diagnostic utility of MRP-8/14 in patients presenting to the emergency room with symptoms concerning for ACS is uncertain. MRP-8/14 was measured in serial serum and plasma samples in a single center prospective cohort-study of patients presenting to the emergency room with non-traumatic chest pain concerning for ACS. Final diagnosis was adjudicated by an endpoint committee. Of patients with baseline MRP-8/14 results (n = 411), the median concentration in serum was 1.57 μg/ml (25th, 75th: 0.87, 2.68) and in plasma was 0.41 μg/ml (<0.4, 1.15) with only moderate correlation between serum and plasma (ρ = 0.40). A final diagnosis of MI was made in 106 (26%). Peak serum MRP-8/14 was higher in patients presenting with MI (p < 0.001). However, the overall diagnostic performance of MRP-8/14 was poor: sensitivity 28% (95% CI 20-38), specificity 82% (78-86), positive predictive value 36% (26-47), and negative predictive value 77% (72-81). The area under the ROC curve for diagnosis of MI with MRP-8/14 was 0.55 (95% CI 0.51-0.60) compared with 0.95 for cTnI. The diagnostic performance was not improved in early-presenters, patients with negative initial cTnI, or using later MRP-8/14 samples. Patients presenting with MI had elevated levels of serum MRP-8/14 compared to patients with non-cardiac chest pain. However, overall diagnostic performance of MRP-8/14 was poor and neither plasma nor serum MRP-8/14 offered diagnostic utility comparable to cardiac troponin.
authors.affiliation: TIMI Study Group, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 350 Longwood Avenue, 1st Floor Offices, Boston, MA 02115, USA.
authors.forename: Amit N
authors.initials: AN
authors.lastname: Vora
authors.forename: Marc P
authors.initials: MP
authors.lastname: Bonaca
authors.forename: Christian T
authors.initials: CT
authors.lastname: Ruff
authors.forename: Petr
authors.initials: P
authors.lastname: Jarolim
authors.forename: Sabina
authors.initials: S
authors.lastname: Murphy
authors.forename: Kevin
authors.initials: K
authors.lastname: Croce
authors.forename: Marc S
authors.initials: MS
authors.lastname: Sabatine
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Simon
authors.forename: David A
authors.initials: DA
authors.lastname: Morrow
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D040501:Calgranulin A / Q000097:blood*; D040502:Calgranulin B / Q000097:blood*; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D040501:Calgranulin A; D040502:Calgranulin B