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 .
Cardiac resynchronization in chronic heart failure.
BACKGROUND Previous studies have suggested that cardiac resynchronization achieved through atrial-synchronized biventricular pacing produces clinical benefits in patients with heart failure who have an intraventricular conduction delay . We conducted a double-blind trial to evaluate this therapeutic approach . METHODS Four hundred fifty-three patients with moderate-to-severe symptoms of heart failure associated with an ejection fraction of 35 percent or less and a QRS interval of 130 msec or more were r and omly assigned to a cardiac-resynchronization group ( 228 patients ) or to a control group ( 225 patients ) for six months , while conventional therapy for heart failure was maintained . The primary end points were the New York Heart Association functional class , quality of life , and the distance walked in six minutes . RESULTS As compared with the control group , patients assigned to cardiac resynchronization experienced an improvement in the distance walked in six minutes ( + 39 vs. + 10 m , P=0.005 ) , functional class ( P<0.001 ) , quality of life ( -18.0 vs. -9.0 points , P= 0.001 ) , time on the treadmill during exercise testing ( + 81 vs. + 19 sec , P=0.001 ) , and ejection fraction ( + 4.6 percent vs. -0.2 percent , P<0.001 ) . In addition , fewer patients in the group assigned to cardiac resynchronization than control patients required hospitalization ( 8 percent vs. 15 percent ) or intravenous medications ( 7 percent vs. 15 percent ) for the treatment of heart failure ( P<0.05 for both comparisons ) . Implantation of the device was unsuccessful in 8 percent of patients and was complicated by refractory hypotension , bradycardia , or asystole in four patients ( two of whom died ) and by perforation of the coronary sinus requiring pericardiocentesis in two others . CONCLUSIONS Cardiac resynchronization results in significant clinical improvement in patients who have moderate-to-severe heart failure and an intraventricular conduction delay
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 .