FAILURE OF EFFECTIVE TREATMENT FOR HEART-FAILURE TO IMPROVE NORMAL CUSTOMARY ACTIVITY

Objectives-To examine the effects of drug treatment on laboratory exer cise tests in relation to measures of daily activity in patients with chronic heart failure. Setting-University teaching hospital. Subjects- 18 patients with mild to moderate chronic heart failure (New York Hear t Association functional class II-III) and 10 age matched healthy cont rols. Methods-Assessments were made before and after 12 weeks of vasod ilator drug treatment. Exercise capacity was measured during two diffe rent types of treadmill exercise, one using a ramp protocol and the ot her a fixed work load. Corridor walk tests at three self selected spee ds were also undertaken and measures of customary activity assessed fr om pedometer scores. Results-Exercise times were significantly increas ed from baseline (P < 0.01) with both treadmill protocols after 12 wee ks of drug treatment, with a positive correlation between the duration of treadmill exercise for both protocols (r = 0.69, P < 0.01). Corrid or walk tests of 100 m at a self selected slow speed also improved (P < 0.02) but these did not correlate with the changes in treadmill exer cise time. The pedometer scores of the patients with heart failure wer e greatly reduced compared with those of the controls (258 (45) x 10(2 ) v 619 (67) x 10(2) steps/week, P < 0.001) and after 12 weeks of trea tment were unchanged (261 (42) x 10(2) steps/week). Conclusions-These data confirm the need to use different exercise protocols when assessi ng the benefits of drug treatment in patients with chronic heart failu re. Treatments that seem effective with conventional laboratory based exercise tests may not improve daily activities. This may reflect a fa ilure of apparently successful treatment and should be considered when intepreting clinical trials.