title: The Effect of beta-blockade on objectively measured physical fitness in patients with abdominal aortic aneurysms--A blinded interventional study.
abstract: BACKGROUND
  Perioperative beta-blockade is widely used, especially before vascular surgery; however, its impact on exercise performance assessed using cardiopulmonary exercise testing (CPET) in this group is unknown. We hypothesized that beta-blocker therapy would significantly improve CPET-derived physical fitness in this group.
  
  
  METHODS
  We recruited patients with abdominal aortic aneurysms (AAA) of <5.5 cm under surveillance. All patients underwent CPET on and off beta-blockers. Patients routinely prescribed beta-blockers underwent a first CPET on medication. Beta-blockers were stopped for one week before a second CPET. Patients not routinely taking beta-blockers underwent the first CPET off treatment, then performed a second CPET after commencement of bisoprolol for at least 48 h. Oxygen uptake (.VO2) at estimated lactate threshold and .VO2 at peak were primary outcome variables. A linear mixed-effects model was fitted to investigate any difference in adjusted CPET variables on and off beta-blockers.
  
  
  RESULTS
  Forty-eight patients completed the study. No difference was observed in .VO2 at estimated lactate threshold and .VO2 at peak; however, a significant decrease in .VE/.VCO2 at estimated lactate threshold and peak, an increase in workload at estimated lactate threshold., O2 pulse and heart rate both at estimated lactate threshold and peak was found with beta-blockers. Patients taking beta-blockers routinely (chronic group) had worse exercise performance (lower .VO2 ).
  
  
  CONCLUSIONS
  Beta blockade has a significant impact on CPET-derived exercise performance, albeit without changing .VO2 at estimated lactate threshold and.VO2 at peak. This supports performance of preoperative CPET on or off beta-blockers depending on local perioperative practice.
  
  
  BACKGROUND
  NCT 02106286.
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Respiratory Research Group, 3rd Floor Clinical Sciences Building Department of Musculoskeletal Biology, Faculty of Health and Life Sciences and mwest@liverpool.ac.uk.
authors.forename: M A
authors.initials: MA
authors.lastname: West
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Respiratory Research Group, 3rd Floor Clinical Sciences Building.
authors.forename: M
authors.initials: M
authors.lastname: Parry
authors.affiliation: Cancer Research UK Liverpool Cancer Trials Unit, Waterhouse Building, University of Liverpool, Liverpool, UK.
authors.forename: R
authors.initials: R
authors.lastname: Asher
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Respiratory Research Group, 3rd Floor Clinical Sciences Building.
authors.forename: A
authors.initials: A
authors.lastname: Key
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Respiratory Research Group, 3rd Floor Clinical Sciences Building Department of Musculoskeletal Biology, Faculty of Health and Life Sciences and.
authors.forename: P
authors.initials: P
authors.lastname: Walker
authors.affiliation: Anaesthesia and Critical Care Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, University Road, Southampton, UK.
authors.forename: L
authors.initials: L
authors.lastname: Loughney
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building.
authors.forename: S
authors.initials: S
authors.lastname: Pintus
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Respiratory Research Group, 3rd Floor Clinical Sciences Building.
authors.forename: N
authors.initials: N
authors.lastname: Duffy
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Respiratory Research Group, 3rd Floor Clinical Sciences Building Department of Musculoskeletal Biology, Faculty of Health and Life Sciences and Anaesthesia and Critical Care Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, University Road, Southampton, UK.
authors.forename: S
authors.initials: S
authors.lastname: Jack
authors.affiliation: Perioperative CPET Research Group, 3rd Floor Clinical Sciences Building Liverpool Vascular & Endovascular Service, Aintree University Hospitals NHS Foundation Trust, Lower Lane, Liverpool, UK Department of Musculoskeletal Biology, Faculty of Health and Life Sciences and.
authors.forename: F
authors.initials: F
authors.lastname: Torella
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D015308:Anaerobic Threshold / Q000187:drug effects; D017544:Aortic Aneurysm, Abdominal / Q000188:drug therapy* / Q000503:physiopathology*; D017298:Bisoprolol / Q000627:therapeutic use; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D019990:Perioperative Care; D010809:Physical Fitness; D011446:Prospective Studies; D013147:Spirometry
chemical_list: D000319:Adrenergic beta-Antagonists; D019344:Lactic Acid; D017298:Bisoprolol
keywords: abdominal aortic aneurysm; anaerobic threshold; beta-blockers; cardiopulmonary exercise test; fitness; surgery