title: Deceptive meaning of oxygen uptake measured at the anaerobic threshold in patients with systolic heart failure and atrial fibrillation.
abstract: Oxygen uptake at the anaerobic threshold (VO2AT), a submaximal exercise-derived variable, independent of patients' motivation, is a marker of outcome in heart failure (HF). However, previous evidence of VO2AT values paradoxically higher in HF patients with permanent atrial fibrillation (AF) than in those with sinus rhythm (SR) raised uncertainties.
  
  
  
  We tested the prognostic role of VO2AT in a large cohort of systolic HF patients, focusing on possible differences between SR and AF.
  
  
  
  Altogether 2976 HF patients (2578 with SR and 398 with AF) were prospectively followed. Besides a clinical examination, each patient underwent a maximal cardiopulmonary exercise test (CPET).
  
  
  
  The follow-up was analysed for up to 1500 days. Cardiovascular death or urgent cardiac transplantation occurred in 303 patients (250 (9.6%) patients with SR and 53 (13.3%) patients with AF, p = 0.023). In the entire population, multivariate analysis including peak oxygen uptake (VO2) showed a prognostic capacity (C-index) similar to that obtained including VO2AT (0.76 vs 0.72). Also, left ventricular ejection fraction, ventilation vs carbon dioxide production slope, β-blocker and digoxin therapy proved to be significant prognostic indexes. The receiver-operating characteristic (ROC) curves analysis showed that the best predictive VO2AT cut-off for the SR group was 11.7 ml/kg/min, while it was 12.8 ml/kg/min for the AF group.
  
  
  
  VO2AT, a submaximal CPET-derived parameter, is reliable for long-term cardiovascular mortality prognostication in stable systolic HF. However, different VO2AT cut-off values between SR and AF HF patients should be adopted.
authors.affiliation: Department of Clinical and Molecular Medicine, "La Sapienza" University of Rome, Italy Centro Cardiologico Monzino, IRCCS, Italy.
authors.forename: Damiano
authors.initials: D
authors.lastname: Magrì
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Italy Department of Clinical Sciences and Community Health, University of Milano, Italy piergiuseppe.agostoni@unimi.it.
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Agostoni
authors.affiliation: Divisione di Cardiologia Riabilitativa, Fondazione Salvatore Maugeri, IRCCS, Istituto Scientifico di Veruno, Italy.
authors.forename: Ugo
authors.initials: U
authors.lastname: Corrà
authors.affiliation: Fondazione Gabriele Monasterio, CNR-Regione Toscana, Italy Scuola Superiore S. Anna, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Passino
authors.affiliation: Division of Cardiology, "S. Maugeri" Foundation, IRCCS, Institute of Cassano Murge, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Scrutinio
authors.affiliation: Department of Advanced Biomedical Sciences, "Federico II" University, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Perrone-Filardi
authors.affiliation: Department of Cardiology, University of Foggia, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Correale
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Italy.
authors.forename: Gaia
authors.initials: G
authors.lastname: Cattadori
authors.affiliation: Cardiology, Department of Medical and Surgical Specialities, Radiological Sciences, and Public Health, University of Brescia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Metra
authors.affiliation: Dipartimento Cardiologico "A. De Gasperis", Ospedale Cà Granda- A.O. Niguarda, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Girola
authors.affiliation: UOC Cardiologia, G da Saliceto Hospital, Italy.
authors.forename: Massimo F
authors.initials: MF
authors.lastname: Piepoli
authors.affiliation: Cardiovascular Department, Ospedali Riuniti and University of Trieste, Italy.
authors.forename: AnnaMaria
authors.initials: A
authors.lastname: Iorio
authors.affiliation: Fondazione Gabriele Monasterio, CNR-Regione Toscana, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Emdin
authors.affiliation: Fondazione Salvatore Maugeri, IRCCS, Istituto Scientifico di Tradate, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Raimondo
authors.affiliation: Cardiology Division, Cardiac Arrhythmia Center and Cardiomyopathies Unit, San Camillo-Forlanini Hospital, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Re
authors.affiliation: Section of Cardiology, Department of Medicine, University of Verona, Italy.
authors.forename: Mariantonietta
authors.initials: M
authors.lastname: Cicoira
authors.affiliation: Cardiologia Riabilitativa, Azienda Ospedali Riuniti di Ancona, Italy.
authors.forename: Romualdo
authors.initials: R
authors.lastname: Belardinelli
authors.affiliation: Heart Failure Unit, IRCCS Policlinico San Donato, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Guazzi
authors.affiliation: Cardiologia SUN, Ospedale Monaldi (Azienda dei Colli), Seconda Università di Napoli, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Limongelli
authors.affiliation: Mediterranean Institute for Transplantation and Advanced Specialized Therapies, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Clemenza
authors.affiliation: Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Istituto Auxologico Italiano, Milan, Italy & Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
authors.affiliation: Dipartimento Cardiologico "A. De Gasperis", Ospedale Cà Granda- A.O. Niguarda, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Frigerio
authors.affiliation: Department of Clinical and Molecular Medicine, "La Sapienza" University of Rome, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Casenghi
authors.affiliation: Cardiology Division, Santo Spirito Hospital, Italy.
authors.forename: Angela B
authors.initials: AB
authors.lastname: Scardovi
authors.affiliation: Cardiology Division, Santo Spirito Hospital, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ferraironi
authors.affiliation: Centro Cardiovascolare, Azienda per i Servizi Sanitari n°1, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Lenarda
authors.affiliation: Division of Cardiology, Salvatore Maugeri Foundation, IRCCS, Institute of Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Bussotti
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Apostolo
authors.affiliation: Department of Advanced Biomedical Sciences, "Federico II" University, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Paolillo
authors.affiliation: Division of Cardiology, "S. Maugeri" Foundation, IRCCS, Institute of Cassano Murge, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: La Gioia
authors.affiliation: SDN Foundation, Institute of Diagnostic and Nuclear Development, Napoli, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Gargiulo
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Palermo
authors.affiliation: Mediterranean Institute for Transplantation and Advanced Specialized Therapies, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Minà
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Farina
authors.affiliation: Section of Cardiology, Department of Medicine, University of Verona, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Battaia
authors.affiliation: Southampton Statistical Sciences Research Institute & School of Mathematics, University of Southampton, United Kingdom Department of Politic Sciences, Università "Roma Tre", Italy.
authors.forename: Antonello
authors.initials: A
authors.lastname: Maruotti
authors.affiliation: Cardiologia SUN, Ospedale Monaldi (Azienda dei Colli), Seconda Università di Napoli, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pacileo
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Contini
authors.affiliation: Dipartimento Cardiologico "A. De Gasperis", Ospedale Cà Granda- A.O. Niguarda, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Oliva
authors.affiliation: Cardiology Division, Santo Spirito Hospital, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ricci
authors.affiliation: Cardiovascular Department, Ospedali Riuniti and University of Trieste, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
mesh_terms: D000368:Aged; D015308:Anaerobic Threshold; D019540:Area Under Curve; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D005080:Exercise Test; D005260:Female; D054143:Heart Failure, Systolic / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D016027:Heart Transplantation; D006801:Humans; D007558:Italy; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012307:Risk Factors; D013997:Time Factors
keywords: Heart failure; anaerobic threshold; atrial fibrillation; exercise; prognosis