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 .
Double-blind, placebo-controlled study of the long-term efficacy of carvedilol in patients with severe chronic heart failure.
BACKGROUND Clinical trials have shown that beta-adrenergic blocking drugs are effective and well tolerated in patients with mild to moderate heart failure , but the utility and safety of these drugs in patients with advanced disease have not been evaluated . METHODS AND RESULTS We enrolled 56 patients with severe chronic heart failure into a double-blind , placebo-controlled study of the vasodilating beta-blocker carvedilol .  All patients had advanced heart failure , as evidence d by a mean left ventricular ejection fraction of 0.16 + /- 0.01 and a mean maximal oxygen consumption of 13.6 + /- 0.6 mL.kg-1.min-1 despite digitalis , diuretics , and an angiotensin-converting enzyme inhibitor ( if tolerated ) . After a 3-week , open-label , up-titration period , 49 of the 56 patients were assigned ( in a double-blind fashion using a 2:1 r and omization ) to receive either carvedilol ( 25 mg BID , n = 33 ) or matching placebo ( n = 16 ) for 14 weeks , while background therapy remained constant . Hemodynamic and functional variables were measured at the start and end of the study . Compared with the placebo group , patients in the carvedilol group showed improved cardiac performance , as reflected by an increase in left ventricular ejection fraction ( P = .005 ) and stroke volume index ( P = .010 ) and a decrease in pulmonary wedge pressure , mean right atrial pressure , and systemic vascular resistance ( P = .003 , .002 , and .017 , respectively ) . In addition , compared with placebo , patients treated with carvedilol benefited clinical ly , as shown by an improvement in symptom scores ( P = .002 ) , functional class ( P = .013 ) , and submaximal exercise tolerance ( P = .006 ) . The combined risk of death , worsening heart failure , and life-threatening ventricular tachyarrhythmia was lower in the carvedilol group than in the placebo group ( P = .028 ) , but carvedilol-treated patients had more dizziness and advanced heart block . CONCLUSIONS Carvedilol produces clinical and hemodynamic improvement in patients who have severe heart failure despite treatment with angiotensin-converting enzyme inhibitors
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 .