title: Permanent atrial fibrillation affects exercise capacity in chronic heart failure patients.
abstract: OBJECTIVE
  The influence of permanent atrial fibrillation on exercise tolerance and cardio-respiratory function during exercise in heart failure (HF) is unknown.
  
  
  RESULTS
  We retrospectively compared the results of 942 cardiopulmonary exercise tests, performed consecutively at seven Italian laboratories, in HF patients with atrial fibrillation (n = 180) and sinus rhythm (n = 762). By multivariable logistic regression analysis, peak VO(2) (OR 0.376, 95% CI 0.240-0.588, P < 0.0001), O(2)pulse (VO(2)/heart rate, HR) (OR 0.236, 95% CI 0.152-0.366, P < 0.0001), VCO(2) (OR 3.97, 95% CI 2.163-7.287, P < 0.0001), and ventilation (OR 1.38, 95% CI 1.045-1.821, P = 0.0231) were independently associated with atrial fibrillation. Anaerobic threshold (AT) was identified in 132 of 180 (73%) atrial fibrillation and in 649 of 762 (85%) sinus rhythm patients (P = 0.0002). By multivariable logistic regression analysis, only peak VO(2) (OR 0.214, 95% CI 0.155-0.296, P < 0.0001) was independently associated with unidentified AT. At AT, atrial fibrillation HF patients had higher HR (P < 0.0001) and higher VO(2) (P < 0.001) compared with sinus rhythm HF patients. Among AT variables, by multivariable logistic regression analysis, only HR was an independent predictor of atrial fibrillation.
  
  
  CONCLUSIONS
  In HF patients with permanent atrial fibrillation, exercise performance is reduced as reflected by reduced peak VO(2). The finding of unidentified AT is associated with a poor performance. In atrial fibrillation patients, VO(2) is higher at AT whereas lower at peak. This last observation raises uncertainties about the use of AT data to define performance and prognosis of HF patients with atrial fibrillation.
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Istituto di Cardiologia, Università di Milano, via Parea 4, 20138 Milano, Italy. piergiuseppe.agostoni@unimi.it
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Agostoni
authors.forename: Michele
authors.initials: M
authors.lastname: Emdin
authors.forename: Ugo
authors.initials: U
authors.lastname: Corrà
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Veglia
authors.forename: Damiano
authors.initials: D
authors.lastname: Magrì
authors.forename: Calogero C
authors.initials: CC
authors.lastname: Tedesco
authors.forename: Emanuela
authors.initials: E
authors.lastname: Berton
authors.forename: Claudio
authors.initials: C
authors.lastname: Passino
authors.forename: Erika
authors.initials: E
authors.lastname: Bertella
authors.forename: Federica
authors.initials: F
authors.lastname: Re
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mezzani
authors.forename: Romualdo
authors.initials: R
authors.lastname: Belardinelli
authors.forename: Chiara
authors.initials: C
authors.lastname: Colombo
authors.forename: Rocco
authors.initials: R
authors.lastname: La Gioia
authors.forename: Marco
authors.initials: M
authors.lastname: Vicenzi
authors.forename: Alberto
authors.initials: A
authors.lastname: Giannoni
authors.forename: Domenico
authors.initials: D
authors.lastname: Scrutinio
authors.forename: Pantaleo
authors.initials: P
authors.lastname: Giannuzzi
authors.forename: Claudio
authors.initials: C
authors.lastname: Tondo
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Lenarda
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
authors.forename: Massimo F
authors.initials: MF
authors.lastname: Piepoli
authors.forename: Marco
authors.initials: M
authors.lastname: Guazzi
mesh_terms: D015308:Anaerobic Threshold / Q000502:physiology*; D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology*; D002908:Chronic Disease; D015331:Cohort Studies; D018450:Disease Progression; D004562:Electrocardiography; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome