title: Exercise performance in patients with end-stage heart failure after implantation of a left ventricular assist device and after heart transplantation: an outlook for permanent assisting?
abstract: OBJECTIVE
  We sought to study exercise capacity at different points in time after left ventricular assist device (LVAD) implantation and subsequent heart transplantation (HTx).
  
  
  BACKGROUND
  The lack of donor organs warrants alternatives for transplantation.
  
  
  METHODS
  Repeat treadmill testing with respiratory gas analysis was performed in 15 men with a LVAD. Four groups of data are presented. In group A (n = 10), the exercise capacities at 8 weeks and 12 weeks after LVAD implantation were compared. In group B (n = 15), the data at 12 weeks are presented in more detail. In group C (n = 9), sequential analysis of exercise capacity was performed at 12 weeks after LVAD implantation and at 12 weeks and one year after HTx. In group D, exercise performance one year after HTx in patients with (n = 10) and without (n = 20) a previous assist device was compared.
  
  
  RESULTS
  In group A, peak oxygen consumption (Vo2) increased from 21.3+/-3.8 to 24.2+/-4.8 ml/kg body weight per min (p < 0.003), accompanied by a decrease in peak minute ventilation/ carbon dioxide production (VE/Vco2) (39.4+/-10.1 to 36.3+/-8.2; p < 0.03). In group B, peak Vo2 12 weeks after LVAD implantation was 23.0+/-4.4 ml/kg per min. In group C, levels of peak Vo2 12 weeks after LVAD implantation and 12 weeks and one year after HTx were comparable (22.8+/-5.3, 24.6+/-3.3 and 26.2+/-3.8 ml/kg per min, respectively; p = NS). In group D, there appeared to be no difference in percent predicted peak Vo2 in patients with or without a previous LVAD (68+/-13% vs. 74+/-15%; p < 0.37), although, because of the small numbers, the power of this comparison is limited (0.45 to detect a difference of 10%).
  
  
  CONCLUSIONS
  Exercise capacity in patients with a LVAD increases over time; 12 weeks after LVAD implantation, Vo2 is comparable to that at 12 weeks and one year after HTx. Previous LVAD implantation does not seem to adversely affect exercise capacity after HTx.
authors.affiliation: Heart Failure and Heart Transplantation Unit, Heart Lung Center Utrecht, University Medical Center Utrecht, The Netherlands. n.dejonge@azu.nl
authors.forename: N
authors.initials: N
authors.lastname: de Jonge
authors.forename: H
authors.initials: H
authors.lastname: Kirkels
authors.forename: J R
authors.initials: JR
authors.lastname: Lahpor
authors.forename: C
authors.initials: C
authors.lastname: Klöpping
authors.forename: E J
authors.initials: EJ
authors.lastname: Hulzebos
authors.forename: A B
authors.initials: AB
authors.lastname: de la Rivière
authors.forename: E O
authors.initials: EO
authors.lastname: Robles de Medina
mesh_terms: D000328:Adult; D005080:Exercise Test; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery*; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D011182:Postoperative Care; D013997:Time Factors