The body weight-walking distance product as a superior parameter in determining the VO2 on-kinetics in coronary artery disease.

Abstract

The 6-minute walk test is frequently used to assess the functional capacity of the cardiac disease population. Nevertheless, anthropometric differences can confound or misestimate performance, which highlights the need for new parameters. This study aimed to investigate the potential of the body weight-walking distance product (D·W) compared to the 6-minute walk test distance to predict exercise capacity measured by oxygen uptake (VO2) on-kinetics in coronary artery disease (CAD) patients. A cross-sectional study was conducted in a tertiary-care reference institution. Forty-six participants with multivessel CAD with and without left ventricular dysfunction underwent a 6-minute walk test with simultaneous use of mobile telemetric cardiopulmonary monitoring to evaluate VO2 kinetics and other cardiorespiratory responses. The Borg rating of perceived exertion for lower limb discomfort was only correlated with the D·W (P=0.007). The percent predicted and actual distance were only modestly to moderately correlated with VO2 on-kinetics (R2=0.12 and R2=0.29, P<0.05). All the associations of VO2 on-kinetics parameters were improved, showing a stronger correlation to the D·W (R2=0.49, P<0.0001), which also had a larger effect size to identify differences between coronary disease patients compared to distance walked (d=1.32 vs d=0.84). The D·W demonstrated potential to be better than the distance walked in determining VO2 on-kinetics in participants with CAD with and without left ventricular dysfunction.