title: Test-retest reliability of skeletal muscle oxygenation measurements during submaximal cycling exercise in patients with chronic heart failure.
abstract: The potential purpose of near-infrared spectroscopy (NIRS) as a clinical application in patients with chronic heart failure (CHF) is the identification of limitations in O2delivery or utilization during exercise. The objective of this study was to evaluate absolute and relative test-retest reliability of skeletal muscle oxygenation measurements in patients with CHF. Thirty patients with systolic heart failure (left ventricular ejection fraction 31 ± 8%) performed 6-min constant-load cycling tests at 80% of the anaerobic threshold (AT) with tissue saturation index (TSI) measurement at the vastus lateralis. Tests were repeated after 10 ± 5 days to evaluate reliability. Absolute reliability was assessed with limits of agreement (LoA, expressed as bias ± random error) and coefficients of variation (CV) for absolute values (LoA range: 0·4 ± 6·2% to 0·6 ± 7·9%; CV range: 4·7-7·1%), amplitudes (LoA range -0·5 ± 5·8% to -0·7 ± 6·8%; CV range: 26·2-42·1%), onset and recovery kinetics (mean response times; LoA 0·4 ± 9·5 s, CV 23·5% and LoA -5·8 ± 50·8 s, CV 67·4% respectively) and overshoot characteristics (CV range 45·7-208·6%). Relative reliability was assessed with intraclass correlation coefficients for absolute values (range 0·74-0·90), amplitudes (range 0·85-0·92), onset and recovery kinetics (0·53 and 0·51, respectively) and overshoot characteristics (range 0·17-0·74). In conclusion, absolute reliability of absolute values and onset kinetics seems acceptable for serial within-subject comparison, and as such, for evaluation of treatment effects. Absolute reliability of amplitudes and recovery kinetics is considered unsatisfactory. Relative reliability of absolute values and amplitudes is sufficient for purposes of physiological distinction between patients with CHF. Despite lower relative reliability, kinetics may still be useful for clinical application.
authors.affiliation: Department of Cardiology, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Niemeijer
authors.affiliation: Department of Cardiology, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Ruud F
authors.initials: RF
authors.lastname: Spee
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Jasper P
authors.initials: JP
authors.lastname: Jansen
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Antonetta B C
authors.initials: AB
authors.lastname: Buskermolen
authors.affiliation: Department of Medical Physics, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Thomas
authors.initials: T
authors.lastname: van Dijk
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands.|Department of Medical Physics, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Pieter F F
authors.initials: PF
authors.lastname: Wijn
authors.affiliation: Department of Cardiology, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Hareld M C
authors.initials: HM
authors.lastname: Kemps
mesh_terms: D000368:Aged; D015308:Anaerobic Threshold; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D000072038:Cardiac Rehabilitation / Q000379:methods*; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D020127:Recovery of Function; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left
chemical_list: D015415:Biomarkers; D010100:Oxygen
keywords: heart failure; intraclass correlation coefficient; limits of agreement; near-infrared spectroscopy; repeatability; reproducibility