title: Outcome and Impact of Aortic Valve Replacement in Patients With Preserved LVEF and Low-Gradient Aortic Stenosis.
abstract: BACKGROUND
  Low mean transvalvular gradient (<40 mm Hg) and small aortic valve area (<1.0 cm(2)) in patients with aortic stenosis (AS) and preserved left ventricular ejection fraction raises uncertainty about the actual severity of the stenosis and survival benefit of aortic valve replacement (AVR).
  
  
  OBJECTIVE
  This study analyzed studies of mortality and survival impact of AVR in patients with low-gradient (LG) AS and preserved left ventricular ejection fraction, including paradoxical low-flow (i.e., stroke volume index <35 ml/m(2)), low-gradient (LF-LG) and normal-flow, low-gradient (NF-LG), and those with high-gradient (≥ 40 mm Hg) AS or moderate AS.
  
  
  METHODS
  Studies published between 2005 and 2015 were analyzed. Primary outcome was the survival benefit associated with AVR. Secondary outcome was overall mortality regardless of treatment.
  
  
  RESULTS
  Eighteen studies were included in the analysis. Patients with LF-LG AS have increased mortality compared with patients with moderate AS (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.31 to 2.17), NF-LG (HR: 1.80; 95% CI: 1.29 to 2.51), and high-gradient (HR: 1.67; 95% CI: 1.16 to 2.39) AS. AVR was associated with reduced mortality in patients with LF-LG (HR: 0.44; 95% CI: 0.25 to 0.77). Similar benefit occurred with AVR in patients with NF-LG (HR: 0.48; 95% CI: 0.28 to 0.83). Compared with patients with high-gradient AS, those with LF-LG were less likely to be referred to AVR (odds ratio: 0.32; 95% CI: 0.21 to 0.49).
  
  
  CONCLUSIONS
  Patients with paradoxical LF-LG AS and NF-LG AS have increased risk of mortality compared with other subtypes of AS with preserved left ventricular ejection fraction, and improved outcome with AVR.
authors.affiliation: Centro Cardiovascular, Hospital de Clinicas, Universidad de la Republica, Montevideo, Uruguay. Electronic address: victor_dayan@hotmail.com.
authors.forename: Victor
authors.initials: V
authors.lastname: Dayan
authors.affiliation: Centro Cardiovascular, Hospital de Clinicas, Universidad de la Republica, Montevideo, Uruguay.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Vignolo
authors.affiliation: Centre Hospitalier Universitaire de Limoges, Limoges, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Magne
authors.affiliation: Québec Heart and Lung Institute, Laval University, Quebec, Canada.
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Clavel
authors.affiliation: Centre Hospitalier Universitaire de Limoges, Limoges, France.
authors.forename: Dania
authors.initials: D
authors.lastname: Mohty
authors.affiliation: Québec Heart and Lung Institute, Laval University, Quebec, Canada. Electronic address: philippe.pibarot@med.ulaval.ca.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pibarot
mesh_terms: D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D004452:Echocardiography / Q000379:methods; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods / Q000401:mortality; D006801:Humans; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D013318:Stroke Volume; D016019:Survival Analysis; D016896:Treatment Outcome; D016277:Ventricular Function, Left
keywords: aortic valve replacement; low gradient aortic stenosis; paradoxical flow aortic stenosis