title: Factors Associated with Low Flow in Aortic Valve Stenosis.
abstract: BACKGROUND
  Low-flow low-gradient aortic stenosis (AS) is a predictor of worse outcome compared with normal-flow AS. Although depressed left ventricular ejection fraction (LVEF) is associated with low flow, there is less evidence to support the role of other indices of cardiac structure and function.
  
  
  METHODS
  Clinical and echocardiographic data from patients with native AS and valve areas ≤ 1.0 cm(2) were retrospectively analyzed to identify characteristics that are associated with low-flow low-gradient AS.
  
  
  RESULTS
  In total, 941 patients were included. On multivariate analysis, factors independently associated with low flow (stroke volume index < 35 mL/m(2)) included worse right ventricular systolic function, atrial fibrillation, lower LVEF, and higher left ventricular mass, with moderate or severe mitral regurgitation independently associated with low flow in the 694 patients (74%) with preserved LVEFs.
  
  
  CONCLUSIONS
  Right ventricular dysfunction and atrial fibrillation are independently associated with low-flow low-gradient AS, while moderate or severe MR is independently associated with low flow in patients with preserved LVEF. These associations with low flow in AS are clinically important to recognize, to avoid underestimation of AS severity.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: Darryl P
authors.initials: DP
authors.lastname: Leong
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Stephen
authors.initials: S
authors.lastname: Pizzale
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Haroun
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Payam
authors.initials: P
authors.lastname: Yazdan-Ashoori
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Karim
authors.initials: K
authors.lastname: Ladak
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Yang Yang
authors.initials: YY
authors.lastname: Sun
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Faisal
authors.initials: F
authors.lastname: Dalak
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Said
authors.initials: S
authors.lastname: Al-Maashani
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Esam A
authors.initials: EA
authors.lastname: Elbarasi
authors.affiliation: Universita delle Marche, Ancona, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Masiero
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Sami
authors.initials: S
authors.lastname: Ghazal
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada. Electronic address: hisham.dokainish@phri.ca.
authors.forename: Hisham
authors.initials: H
authors.lastname: Dokainish
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000502:physiology*; D015897:Comorbidity; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology
keywords: Aortic stenosis; Echocardiography; Hemodynamics; Low-flow low-gradient aortic stenosis; Stroke volume