Comparison of the studies investigating reliability shows that the 6MWT has good reproducibility .
The 6MWT demonstrates moderate correlation with peak VO(2 ) levels , and ability to predict VO(2 ) ( functional capacity ) dependent on distance walked .
Cut-off distances vary from 300 to 490 meters depending on the study ; if total distance walked remains equal or less than these values , the 6MWT retains its strong predictive value .
The 6MWT has good reliability , moderate validity , and a significant ability to predict functional capacity in patients with CHF who do not walk greater than 490 meters
PURPOSE To evaluate the reliability and validity of the six-minute walk test ( 6MWT ) with respect to its ability to predict functional capacity in patients with chronic heart failure .
A shuttle walk test for assessment of functional capacity in chronic heart failure.
BACKGROUND Peak oxygen uptake ( peak VO(2 ) ) is a reference parameter in the assessment of functional capacity of patients with chronic heart failure , but the procedure for cardiopulmonary exercise testing with expired gas analysis is complex and expensive , so more simple and available methods are desirable . METHODS We compared the usefulness of a time-limited walk test , the 6-minute walk test ( 6-MT ) , with that of a symptom-limited walk test , the shuttle walk test ( SWT ) , in the evaluation of patients with moderate to severe chronic heart failure . We prospect ively studied 46 clinical ly stable patients in New York Heart Association class II to IV heart failure with left ventricular ejection fraction < 40 % ( aged 53 + /- 10 years , ejection fraction 23 % + /- 8 % , New York Heart Association functional class 2.8 + /- 0.7 ) . Each patient performed two 6-MT , two SWT and a cardiopulmonary exercise testing within 2 weeks . RESULTS We found a close correlation between distance walked in SWT and peak VO(2 ) ( r = 0.83 , P < .001 ) and a moderate correlation between distance in 6-MT and peak VO(2 ) ( r = 0.69 , P < .001 ) . Both walk tests showed to be reproducible after just one practice walk . All patients who walked > 450 m in SWT had a peak VO(2 ) > 14 mL/kg/min . The overall discriminatory accuracy for SWT distance was greater than that for 6-MT distance for predicting a peak VO(2 ) < 14 mL/kg/min ( area under receiver operator characteristic curves 0.97 and 0.83 respectively , P = .02 ) . Stepwise multivariate regression analysis , including clinical , exercise testing , echocardiographic , radionuclide-angiographic , and rest hemodynamic data , showed that distance walked in SWT was the only independent predictor of peak VO(2 ) ( P < .001 ) and the strongest predictor of percent achieved of age- and sex-predicted peak VO(2 ) ( % PVO(2 ) ) ( P < .001 ) , with only age offering additional information ( P = .02 ) . CONCLUSIONS The SWT shows to be a feasible and safe method to evaluate patients with chronic heart failure that strongly and independently predicts peak VO(2 ) and % PVO(2 . ) This symptom-limited walk test seems to be more useful than 6-MT in the assessment of functional capacity in these patients
Comparison of the studies investigating reliability shows that the 6MWT has good reproducibility .
The 6MWT demonstrates moderate correlation with peak VO(2 ) levels , and ability to predict VO(2 ) ( functional capacity ) dependent on distance walked .
Cut-off distances vary from 300 to 490 meters depending on the study ; if total distance walked remains equal or less than these values , the 6MWT retains its strong predictive value .
The 6MWT has good reliability , moderate validity , and a significant ability to predict functional capacity in patients with CHF who do not walk greater than 490 meters
PURPOSE To evaluate the reliability and validity of the six-minute walk test ( 6MWT ) with respect to its ability to predict functional capacity in patients with chronic heart failure .