Pharmacological trials including patients with more severe heart failure were more likely to show a significant improvement with therapy than trials of milder heart failure .
Using mean values in these trials , the age of patients appeared a more important determinant of 6MWT distance than New York Heart Association classification .
The 6MWT has not yet been proven to be a robust test for the identification of effective pharmacological interventions although it appears useful for the assessment of cardiac resynchronization therapy .
The results of the 6MWT were concordant with changes in symptoms , suggesting that it may be used as supportive evidence for symptom benefit .
AIMS The 6 min walk test ( 6MWT ) is commonly used in clinical trials to assess treatments for heart failure , but its ability to distinguish between effective and ineffective treatments is question able .
The aim of this study is to investigate , using a systematic literature review , the utility of the 6MWT as a measure of the effectiveness of treatment in r and omized controlled trials of heart failure .
Long-term clinical effect of hemodynamically optimized cardiac resynchronization therapy in patients with heart failure and ventricular conduction delay.
OBJECTIVES We sought to compare the short- and long-term clinical effects of atrial synchronous pre-excitation of one ( univentricular ) or both ventricles ( biventricular ) , that provide cardiac resynchronization therapy ( CRT ) . BACKGROUND In patients with heart failure ( HF ) who have a ventricular conduction delay , CRT improves systolic hemodynamic function . The clinical benefit of CRT is still being investigated . METHODS Forty-one patients were r and omized to four weeks of first treatment with biventricular or univentricular stimulation  , followed by four weeks without treatment , and then four weeks of a second treatment with the opposite stimulation . The best CRT stimulation was continued for nine months . Cardiac resynchronization therapy was optimized by hemodynamic testing at implantation . The primary end points were exercise capacity measures . Data were analyzed by two-way repeated- measures analysis of variance . RESULTS The left ventricle was selected for univentricular pacing in 36 patients . The clinical effects of univentricular and biventricular CRT were not significantly different . The results of each method were pooled to assess sequential treatment effects . Oxygen uptake during bicycle exercise increased from 9.48 to 10.4 ml/kg/min at the anaerobic threshold ( p = 0.03 ) and from 12.5 to 14.3 ml/kg/min at peak exercise ( p < 0.001 ) with the first treatment , and from 10.0 to 10.7 ml/kg/min at the anaerobic threshold ( p = 0.2 ) and from 13.4 to 15.2 ml/kg/min at peak exercise ( p = 0.002 ) with the second treatment . The 6-min walk distance increased from 342 m at baseline to 386 m after the first treatment ( p < 0.001 ) and to 416 m after the second treatment ( p = 0.03 ) . All improvements persisted after 12 months of therapy . CONCLUSIONS Cardiac resynchronization therapy produces a long-term improvement in the clinical symptoms of patients with HF who have a ventricular conduction delay . The differences between optimized biventricular and univentricular therapy appear to be small for short-term treatment
Pharmacological trials including patients with more severe heart failure were more likely to show a significant improvement with therapy than trials of milder heart failure .
Using mean values in these trials , the age of patients appeared a more important determinant of 6MWT distance than New York Heart Association classification .
The 6MWT has not yet been proven to be a robust test for the identification of effective pharmacological interventions although it appears useful for the assessment of cardiac resynchronization therapy .
The results of the 6MWT were concordant with changes in symptoms , suggesting that it may be used as supportive evidence for symptom benefit .
AIMS The 6 min walk test ( 6MWT ) is commonly used in clinical trials to assess treatments for heart failure , but its ability to distinguish between effective and ineffective treatments is question able .
The aim of this study is to investigate , using a systematic literature review , the utility of the 6MWT as a measure of the effectiveness of treatment in r and omized controlled trials of heart failure .