title: Takotsubo cardiomyopathy has a unique cardiac biomarker profile: NT-proBNP/myoglobin and NT-proBNP/troponin T ratios for the differential diagnosis of acute coronary syndromes and stress induced cardiomyopathy.
abstract: BACKGROUND
  Takotsubo cardiomyopathy (TC) usually is not recognized until heart catheterization reveals typical wall motion abnormalities in the absence of significant coronary artery disease. It was our aim to identify TC by its unique cardiac biomarker profile at an early stage and, preferably, with non-invasive procedures only.
  
  
  METHODS
  Ratios of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and myoglobin, NT-proBNP and troponin T (TnT), NT-proBNP and creatinekinase-MB (CK-MB) were compared in patients with TC (n=39), patients with ST-elevation myocardial infarction (STEMI, n=48) and patients with non-ST-elevation myocardial infarction (NSTEMI, n=34). Biomarkers were recorded serially at admission and at the three consecutive days. Optimal cut-off values to distinguish TC from STEMI and NSTEMI were calculated with receiver operator characteristic (ROC) curves.
  
  
  RESULTS
  At admission a NT-proBNP (ng/l)/myoglobin (μg/l) ratio of 3.8, distinguished TC from STEMI (sensitivity: 89%, specificity: 90%), while a NT-proBNP (ng/l)/myoglobin (μg/l) ratio of 14 separated well between TC and NSTEMI (sensitivity: 65%, specificity: 90%). Best differentiation of TC and ACS was possible with the ratio of peak levels of NT-proBNP (ng/l)/TnT (μg/l). A cut-off value of NT-proBNP (ng/l)/TnT (μg/l) ratio of 2889, distinguished TC from STEMI (sensitivity: 91%, specificity: 95%), while a NT-proBNP (ng/l)/TnT (μg/l) ratio of 5000 separated well between TC and NSTEMI (sensitivity: 83%, specificity: 95%).
  
  
  CONCLUSIONS
  TC goes along with a singular cardiac biomarker profile, which might be useful to identify patients with TC among patients presenting with acute coronary syndromes (ACS).
authors: Cardiovascular Center Cardiology, University Hospital Zurich, Zurich, Switzerland.
authors: Georg M
authors: GM
authors: Fröhlich
authors: Boris
authors: B
authors: Schoch
authors: Florian
authors: F
authors: Schmid
authors: Philipp
authors: P
authors: Keller
authors: Isabella
authors: I
authors: Sudano
authors: Thomas F
authors: TF
authors: Lüscher
authors: Georg
authors: G
authors: Noll
authors: Frank
authors: F
authors: Ruschitzka
authors: Frank
authors: F
authors: Enseleit
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012189:Retrospective Studies; D054549:Takotsubo Cardiomyopathy / Q000097:blood* / Q000175:diagnosis*; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D009211:Myoglobin; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain