title: Impact of classic and paradoxical low flow on survival after aortic valve replacement for severe aortic stenosis.
abstract: BACKGROUND
  Low flow (LF) can occur with reduced (classic) or preserved (paradoxical) left ventricular ejection fraction (LVEF).
  
  
  OBJECTIVE
  The objective of this study was to compare outcomes of patients with low ejection fraction (LEF), paradoxical low flow (PLF), and normal flow (NF) after aortic valve replacement (AVR).
  
  
  METHODS
  We examined 1,154 patients with severe aortic stenosis (AS) who underwent AVR with or without coronary artery bypass grafting.
  
  
  RESULTS
  Among these patients, 206 (18%) had LEF as defined by LVEF of <50%; 319 (28%) had PLF as defined by LVEF of ≥50% but stroke volume indexed to body surface area (SVi) of ≤35 ml ∙ m(-2); and 629 (54%) had NF, as defined by LVEF of ≥50% and SVi of >35 ml ∙ m(2). Aortic valve area was lower in low flow/LVEF groups (LEF: 0.71 ± 0.20 cm(2) and PLF: 0.65 ± 0.23 cm(2) vs. NF: 0.77 ± 0.18 cm(2); p < 0.001). The 30-day mortality was higher (p < 0.001) in LEF and PLF groups than in the NF group (6.3% and 6.3% vs. 1.8%, respectively). SVi and PLF group were independent predictors of operative mortality (odds ratio [OR]: 1.18, p < 0.05; and OR: 2.97, p = 0.004; respectively). At 5 years after AVR, overall survival was 72 ± 4% in LEF group, 81 ± 2% in PLF group, and 85 ± 2% in NF group (p < 0.0001).
  
  
  CONCLUSIONS
  Patients with LEF or PLF AS have a higher operative risk, but pre-operative risk score accounted only for LEF and lower LVEF. Patients with LEF had the worst survival outcome, whereas patients with PLF and normal flow had similar survival rates after AVR. As a major predictor of perioperative mortality, SVi should be integrated in AS patients' pre-operative evaluation.
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada. Electronic address: marie-annick.clavel@criucpq.ulaval.ca.
authors: Marie-Annick
authors: MA
authors: Clavel
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Maxime
authors: M
authors: Berthelot-Richer
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Florent
authors: F
authors: Le Ven
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Romain
authors: R
authors: Capoulade
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Abdellaziz
authors: A
authors: Dahou
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Jean G
authors: JG
authors: Dumesnil
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Patrick
authors: P
authors: Mathieu
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Philippe
authors: P
authors: Pibarot
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000401:mortality* / Q000503:physiopathology* / Q000601:surgery; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology*; D015996:Survival Rate; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology
keywords: aortic stenosis; low flow; low ejection fraction; survival