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 .
Effect of beta blockade (carvedilol or metoprolol) on activation of the renin-angiotensin-aldosterone system and natriuretic peptides in chronic heart failure.
Beta blockers are known to suppress renin release in hypertension and in patients taking angiotensin-converting enzyme ( ACE ) inhibitors . This study sought to explore the effect of additional beta blockade on neurohumoral modulation in patients with severe heart failure ( HF ) who received ACE inhibitors . Forty-nine patients with chronic HF who received ACE inhibitors  were given metoprolol 50 mg or carvedilol 25 mg twice daily after a 4-week dose titration period in addition to st and ard therapy in a prospect i ve trial . Sample s of  plasma renin activity ( PRA ) , aldosterone , aminoterminal B-type natriuretic peptide ( N-BNP ) , and atrial natriuretic peptide ( ANP ) were taken at baseline and at 4 , 12 , and 52 weeks after starting therapy . Treatment with either beta blocker significantly lowered PRA at 4 weeks compared with baseline ( -2.0 + /- 0.6 nmol/L/hour , p = 0.006 ) , but at 12 weeks , PRA had reduced to -1.1 + /- 0.6 nmol/L/hour ( p = 0.08 ) , but at 52 weeks , it was not significantly different from baseline ( + 1.05 + /- 0.6 nmol/L/hour , p = 0.13 ) . Aldosterone levels did not change significantly from baseline at 4 or 12 weeks , although there was a nonsignificant trend for lower levels at 52 weeks ( baseline 232 + /- 154 pmol/L , 52 weeks 192 + /- 100 pmol/L , p = 0.09 ) . There was significant reduction in N-BNP and ANP together with an improvement in symptom and left ventricular systolic function at 1-year follow-up . These results indicate that the suppressive effect of beta blockers on PRA in patients with HF taking  ACE inhibitors is temporary , and that there is no significant effect on serum aldosterone levels
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 .