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 .
Randomised study of effect of ibopamine on survival in patients with advanced severe heart failure
BACKGROUND Drugs that improve symptoms in patients with heart failure must also be assessed for their effects on survival .  Ibopamine stimulates DA-1 and DA-2 receptors and causes peripheral and renal vasodilatation ; the drug improves symptoms of heart failure . We assessed the effect of ibopamine on survival in patients with advanced heart failure in a multicentre , r and omised placebo-controlled study . METHODS Patients with advanced severe heart failure ( New York Heart Association classes III and IV ) and evidence of severe left-ventricular disease , who were already receiving optimum treatment for heart failure , were r and omly allocated oral ibopamine 100 mg three times daily or placebo . The primary endpoint was all-cause mortality . The study was design ed to recruit 2200 patients , and the minimum duration of treatment would be 6 months . We did intention-to-treat and on-treatment analyses ; a post-hoc subgroup analysis was also done . FINDINGS After we had recruited 1906 patients the trial was stopped early , because of an excess of deaths among patients in the ibopamine group . 232 ( 25 % ) of 953 patients in the ibopamine group died , compared with 193 ( 20 % ) of 953 patients in the placebo group ( relative risk 1.26 [ 95 % CI 1.04 - 1.53 ] , p = 0.017 ) . The average length of follow-up was 347 days in the ibopamine group and 363 days in the placebo group . In multivariate analysis , only the use of antiarrhythmic drugs at baseline was a significant independent predictor of increased fatality in ibopamine-treated patients . INTERPRETATION Ibopamine seems to increase the risk of death among patients with advanced heart failure who are already receiving optimum therapy , but the reasons for this increase are not clear . Our finding that antiarrhythmic treatment was a significant predictor of increased mortality in ibopamine-treated patients may be important , but exploratory analyses must be interpreted with caution
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 .