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 .
Clinical efficacy of cardiac resynchronization therapy using left ventricular pacing in heart failure patients stratified by severity of ventricular conduction delay.
OBJECTIVES We assessed the clinical efficacy of single-site left ventricular ( LV ) pacing and determined the impact of baseline conduction delay severity on the magnitude of benefit . BACKGROUND Multisite biventricular pacing can improve heart failure ( HF ) symptoms in patients with an intraventricular conduction delay by resynchronizing abnormal ventricular contractions and improving LV systolic function . METHODS Eighty-six patients with at least New York Heart Association functional class II HF , chronic LV systolic dysfunction , normal sinus rhythm , and a QRS interval over 120 ms were implanted for atrial-synchronized LV pacing . The single-blinded , r and omized , controlled , crossover study stratified patients 1:1 by the baseline QRS interval into long ( QRS > 150 ms ) and short ( QRS 120 to 150 ms ) groups , which were compared during a three-month period of active ( univentricular ) pacing and a three-month period of inactive ( ventricular inhibited ) pacing . The primary end point was peak oxygen consumption ( VO(2 ) ) followed by anaerobic threshold , distance walked in 6 min , and quality -of-life question naire score . PATIENTS Twelve patients were withdrawn before r and omization and 17 could not complete both study periods . The short QRS group did not improve in any end point with active pacing . For the long QRS group , peak VO(2 ) increased 2.46 ml/min/kg ( p < 0.001 ) , the anaerobic threshold increased 1.55 ml/min/kg ( p < 0.001 ) , the distance walked in 6 min increased 47 m ( p = 0.024 ) , and the quality -of-life score improved 8.1 points ( p = 0.004 ) . CONCLUSIONS Left ventricular pacing significantly improves exercise tolerance and quality of life in patients with chronic HF , LV systolic dysfunction , and a QRS interval over 150 ms
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 .