Discordance between change in estimated MET during supervised exercise training and change in peak oxygen uptake
Berry R, Keteyian SJ, Saval MA, Brawner CA. Discordance between change in estimated MET during supervised exercise training and change in peak oxygen uptake. J Cardiopulm Rehabil Prev. 2018;38(5):E20.
J Cardiopulm Rehabil Prev
Introduction: Metabolic equivalent of task METs), estimatedfrom exercise trainingworkloads during supervised exercisetraining (SET), are an accepted outcome measurefor cardiac rehabilitation programs. However, it is not clear how well change in estimatedMETs during SET correlate to changes in exercise capacity measured during a symptomlimited from an exercise test.Purpose: Compare the change inMETs estimated from SET workloads to exercise capacity based on measured peak oxygen uptake (VO2) and the 6 minute walk test distance(6MWD).Design: Secondary analysis of the HF-ACTION trial.Methods: Among subjects with HFrEF (ejection fraction =40%) randomized to exercisetraining, we identified 357 (age= 59±11 years; 30% women; 64% white) who performedboth a cardiopulmonary exercise test (CPET) on a treadmill for exercise duration and peakVO2, and a 6 minute walk test at baseline and 3 months, and completed =12 SET visitsduring the same 3 month period. Estimated METs during SET were calculated from treadmill training, with baseline representing the mean of SET visits 2 and 3, and at 3 monthfollow up the mean of the last 2 SET visits. Linear regression was used to determine thePearson correlation and standard error of estimate (SEE) between % change from baselineto 3 months in estimated METs during SET to % change in (1) peak VO2 and, (2) exerciseduration during the CPET, and (3) 6MWD.Results: At baseline the mean±sd estimated METs, peak VO2, exercise duration, and6MWD were 3.0±0.9 METs, 15.4±4.5 mL/kg/min, 10.5±3.7 min, and 384±90 m, respectively. At 3 months each of these increased 29±29%, 8±18%, 28±37%, and 10±32%,respectively (all increases were < 0.05). The correlation and SEE between % change inSET METs and % change in peak VO2 were r= 0.124 (p= 0.02) and 18%, respectively. For% change in SET METs and % change in exercise duration, r= 0.237 (p