title: Aortic stiffness as a marker of cardiac function and myocardial strain in patients undergoing aortic valve replacement.
abstract: BACKGROUND
  Cardiac function and myocardial strain are affected by cardiac afterload, which is in part due to the stiffness of the aortic wall. In this study, we hypothesize that aortic pulse wave velocity (PWV) as a marker of aortic stiffness correlates with conventional clinical and biochemical markers of cardiac function and perioperative myocardial strain in aortic valve replacement (AVR).
  
  
  METHODS
  Patients undergoing AVR for aortic stenosis between June 2010 and August 2012 were recruited for inclusion in this study. PWV, NYHA class and left ventricular (LV) function were assessed pre-operatively. PWV was analysed both as a continuous and dichotomous variable according to age-standardized reference values. B-type natriuretic peptide (BNP) was measured pre-operatively, and at 3 h and 18-24 h after cardiopulmonary bypass (CPB). NYHA class, leg edema, and LV function were recorded at follow-up (409 ± 159 days).
  
  
  RESULTS
  Fifty-six patients (16 females) with a mean age of 71 ± 8.4 years were included, with 50 (89%) patients completing follow-up. The NYHA class of PWV-norm patients was significantly lower than PWV-high patients both pre- and post-operatively. Multiple logistic regression also highlighted PWV-cut off as an independent predictor of NYHA class pre- and post-operatively (OR 8.3, 95% CI [2.27,33.33] and OR 14.44, 95% CI [1.49,139.31] respectively). No significant relationship was observed between PWV and either LV function or plasma BNP.
  
  
  CONCLUSIONS
  In patients undergoing AVR for aortic stenosis, PWV is independently related to pre- and post-operative NYHA class but not to LV function or BNP. These findings provisionally support the use of perioperative PWV as a non-invasive marker of clinical functional status, which when used in conjunction with biomarkers of myocardial strain such as BNP, may provide a holistic functional assessment of patients undergoing aortic valve surgery. However, in order for PWV assessment to be translated into clinical practice and utilised as more than simply a research tool, further validation is required in the form of larger prospective studies specifically designed to assess the relationship between PWV and these functional clinical outcomes.
authors.forename: Emaddin
authors.initials: E
authors.lastname: Kidher
authors.affiliation: The Department of Surgery and Cancer, Imperial College London, St Mary's Hospital, 10th Floor, QEQM Wing, St Mary's Campus, London W2 1NY, UK. leanne.harling@imperial.ac.uk.
authors.forename: Leanne
authors.initials: L
authors.lastname: Harling
authors.forename: Hutan
authors.initials: H
authors.lastname: Ashrafian
authors.forename: Hatam
authors.initials: H
authors.lastname: Naase
authors.forename: Darrel P
authors.initials: DP
authors.lastname: Francis
authors.forename: Paul
authors.initials: P
authors.lastname: Evans
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000503:physiopathology*; D001021:Aortic Valve / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000503:physiopathology / Q000601:surgery*; D001794:Blood Pressure / Q000502:physiology; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D020097:Natriuretic Peptide, Brain / Q000378:metabolism*; D057234:Preoperative Period; D011379:Prognosis; D063177:Pulse Wave Analysis / Q000379:methods; D012189:Retrospective Studies; D059289:Vascular Stiffness / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D020097:Natriuretic Peptide, Brain