title: Diagnostic value of NT-proBNP in identifying impaired coronary flow reserve in asymptomatic moderate or severe aortic stenosis.
abstract: OBJECTIVE
  NT-proBNP has been shown to be a reliable biochemical marker for left ventricular wall stress. The relationship between NT-proBNP and coronary flow reserve (CFR) was evaluated in patients with significant asymptomatic aortic stenosis (AS).
  
  
  METHODS
  A total of 74 patients with moderate or severe AS, mean age 66.68 ± 10.02 years (56.75% males), were enrolled in this prospective study. All patients underwent coronary angiography and had no obstructive coronary disease (defined as having no stenosis >50% in diameter). They had all undergone standard transthoracic Doppler-echo study and adenosine stress transthoracic-echo for CFR measurement and laboratory analysis for NT-proBNP measurement.
  
  
  RESULTS
  The median NT-proBNP value was significantly increased (417.0 pg/ml; interquartile range [IQR]: 176.8-962.2 pg/ml). NT-proBNP was significantly higher in the group with CFR ≤2.5 (median: 549.0 pg/ml; IQR: 311.5-1131.0 pg/ml; as opposed to median: 291.5 pg/ml; IQR: 123.0-636.2 pg/ml; W = 452; p = 0.012). NT-proBNP showed significant negative correlation with CFR (ρ = -0.377, p = 0.001). There was also significant correlation between NT-proBNP and E/E´, S´ and aortic valve resistance. The NT-proBNP value of 334.00 pg/ml was determined as the best cut-off value for the diagnosis of CFR ≤2.5 (area under the curve: 0.67; 95%CI: 0.54-0.79; p < 0.01) and the sensitivity and specificity were 74 and 64%, respectively.
  
  
  CONCLUSIONS
  Elevated NT-proBNP can indicate patients with impaired CFR in asymptomatic moderate or severe AS patients with preserved ejection fraction and nonobstructive coronary arteries.
authors.affiliation: Clinical Centre of Serbia, Cardiology Clinic, Belgrade Medical School, Serbia. markobanovic71@gmail.com
authors.forename: Marko
authors.initials: M
authors.lastname: Banovic
authors.forename: Bosiljka
authors.initials: B
authors.lastname: Vujisic-Tesic
authors.forename: Svetlana
authors.initials: S
authors.lastname: Bojic
authors.forename: Ana
authors.initials: A
authors.lastname: Mladenovic
authors.forename: Svetlana
authors.initials: S
authors.lastname: Ignjatovic
authors.forename: Milan
authors.initials: M
authors.lastname: Petrovic
authors.forename: Danijela
authors.initials: D
authors.lastname: Trifunovic
authors.forename: Ivana
authors.initials: I
authors.lastname: Nedeljkovic
authors.forename: Dejana
authors.initials: D
authors.lastname: Popovic
authors.forename: Mark
authors.initials: M
authors.lastname: Callahan
authors.forename: Petar
authors.initials: P
authors.lastname: Seferovic
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000097:blood / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D003935:Diagnostic Techniques, Cardiovascular; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011446:Prospective Studies; D012039:Regional Blood Flow; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain