title: Aortic augmentation index is independently associated with N-terminal pro B-type natriuretic peptide in patients with peripheral arterial disease.
abstract: OBJECTIVE
  To investigate the relationship of aortic augmentation index (AIx) with N-terminal pro B-type natriuretic peptide (NTproBNP) plasma levels in patients with peripheral arterial disease (PAD) with normal left ventricular (LV) function.
  
  
  METHODS
  Totally, 31 patients (23 males, mean age 65 ± 7.4) with a confirmed diagnosis of PAD of the lower limbs (ankle-brachial pressure index [ABPI] <0.90 in at least 1 leg) were enrolled in this study. All patients underwent pulse wave analysis by applanation tonometry of the radial artery using the SphygmoCor system and had a measurement of plasma NTproBNP levels.
  
  
  RESULTS
  Patients had a mean resting ABPI of 0.62 ± 0.19 and a mean AIx 32.6% ± 6.9. Median (interquartile range) NTproBNP plasma level was 75 (44-210) pg/mL. In a univariate analysis which included age, brachial systolic blood pressure (BSBP), brachial diastolic blood pressure (BDBP), ejection duration index (ED%), heart rate (HR), and NTproBNP, aortic AIx was significantly associated (Spearman rho) with NTproBNP, HR, and ED% (r = .49, P = .006; r = -.72, P = .000, and r = -.42, P = .02, respectively). Multivariate linear regression analysis showed that AIx was associated with NTproBNP (β = 0.38, P = .02) independent of gender, HR, ED%, and use of β-blockers. N-terminal pro B-type natriuretic peptide explained 8% of the variance in aortic AIx, whereas HR explained 15% of the variance.
  
  
  CONCLUSIONS
  In patients with PAD with normal LV systolic function, AIx is independently associated with NTproBNP. Structural changes in the myocardium might occur due to increased LV afterload as a result of increased wave reflections and arterial stiffness due to atherosclerosis leading to an increase in NTproBNP plasma levels.
authors.affiliation: Academic Vascular Surgical Unit, Hull York Medical School & University of Hull, Hull, UK. yousef.shahin@yahoo.co.uk
authors.forename: Yousef
authors.initials: Y
authors.lastname: Shahin
authors.forename: Ian
authors.initials: I
authors.lastname: Chetter
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D001011:Aorta / Q000503:physiopathology*; D062186:Arterial Pressure; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D016014:Linear Models; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D058729:Peripheral Arterial Disease / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D063177:Pulse Wave Analysis; D013599:Systole; D015854:Up-Regulation; D059289:Vascular Stiffness; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain