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 .
Comparative effects of permanent biventricular and right-univentricular pacing in heart failure patients with chronic atrial fibrillation.
BACKGROUND One third of chronic heart failure patients have major intraventricular conduction and uncoordinated ventricular contraction . Non-controlled studies suggest that biventricular pacing may improve haemodynamics and well-being by reducing ventricular asynchrony . The aim of this trial was to assess the clinical efficacy and safety of this new therapy in patients with chronic atrial fibrillation . METHODS Fifty nine NYHA class III patients with left ventricular systolic dysfunction , chronic atrial fibrillation , slow ventricular rate necessitating permanent ventricular pacing , and a wide QRS complex ( paced width > or=200 ms ) , were implanted with transvenous biventricular-VVIR pacemakers . This single-blind , r and omized , controlled , crossover study compared the patients ' parameters , as monitored during two 3-month treatment periods of conventional right-univentricular vs biventricular pacing . The primary end-point was the 6-min walked distance , secondary end-points were peak oxygen uptake , quality -of-life , hospitalizations , patients ' preferred study period and mortality . RESULTS Because of a higher than expected drop-out rate ( 42 % ) , only 37 patients completed both crossover phases . In the intention-to-treat analysis , we did not observe a significant difference . However , in the patients with effective therapy the mean walked distance increased by 9.3 % with biventricular pacing ( 374+/-108 vs 342+/-103 m in univentricular;P = 0.05 ) . Peak oxygen uptake increased by 13 % ( P=0.04 ) . Hospitalizations decreased by 70 % and 85 % of the patients preferred the biventricular pacing period ( P<0.001 ) . CONCLUSION As compared with conventional VVIR pacing , effective biventricular pacing seems to improve exercise tolerance in NYHA class III heart failure patients with chronic atrial fibrillation and wide paced-QRS complexes . Further r and omized controlled studies are required to definitively vali date this therapy in such patients
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 .