title: Long-term outcomes after valve replacement for low-gradient aortic stenosis: impact of prosthesis-patient mismatch.
abstract: BACKGROUND
  The long-term outcomes of patients with low-gradient aortic stenosis (LGAS) after aortic valve replacement (AVR) are poorly defined. The purpose of this study was to define the long-term outcomes of LGAS patients after AVR and to evaluate the potential impact of prosthesis-patient mismatch (PPM) in these patients.
  
  
  RESULTS
  A cohort of 664 patients undergoing AVR for aortic stenosis after 1990 were followed-up prospectively with annual clinical assessment and echocardiography (total follow-up 3447 patient-years; mean follow-up 5.2+/-3.3 years). LGAS was defined as an aortic valve area <1.2 cm2, a mean transvalvular pressure gradient <40 mm Hg, and a left ventricular (LV) ejection fraction <50%, and was present in 79 patients. Rates and correlates of survival, freedom from congestive heart failure (CHF), and LV mass regression after AVR were determined using multivariate regression methods. Ten-year survival and freedom from CHF after AVR were 72.7+/-7.5% and 68.2+/-9.5%, respectively, for patients with LGAS, compared with 89.6+/-1.8% and 84.1+/-4.2% for patients without LGAS (hazard ratio [HR] for death and postoperative CHF, 3.1+/-1.1 and 2.7+/-0.9, respectively; P<0.01). In LGAS patients, PPM, defined as an indexed effective orifice area < or = 0.85 cm2/m2, was independently associated with increased rates of CHF (HR, 3.6+/-2.2; P=0.039), impaired LV mass regression (P=0.037), and a trend toward increased late mortality (HR, 3.0+/-1.9; P=0.084).
  
  
  CONCLUSIONS
  Patients with LGAS have worse long-term outcomes after AVR compared with patients without LGAS. PPM adversely affects the long-term outcomes of LGAS patients and should be avoided in this population.
authors.affiliation: Division of Cardiac Surgery, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kulik
authors.forename: Ian G
authors.initials: IG
authors.lastname: Burwash
authors.forename: Varun
authors.initials: V
authors.lastname: Kapila
authors.forename: Thierry G
authors.initials: TG
authors.lastname: Mesana
authors.forename: Marc
authors.initials: M
authors.lastname: Ruel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology; D001024:Aortic Valve Stenosis / Q000150:complications / Q000601:surgery*; D001830:Body Surface Area; D015331:Cohort Studies; D015897:Comorbidity; D018450:Disease Progression; D018572:Disease-Free Survival; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000517:prevention & control; D011446:Prospective Studies; D012008:Recurrence; D016019:Survival Analysis; D016896:Treatment Outcome; D014463:Ultrasonography; D020257:Ventricular Remodeling