Effects of Exercise Training versus Attention on Plasma B-type Natriuretic Peptide, 6-Minute Walk Test and Quality of Life in Individuals with Heart Failure.

PURPOSE: The purpose of this study was to compare an Exercise Training Group (EX) with an Attention-Control Group (AT-C) to more specifically assess the impact of exercise training on individuals with heart failure (HF). METHODS: Forty-two individuals with HF were randomized to AT-C or EX that met with the same frequency and format of investigator interaction. Baseline, 12- and 24-week measurements of B-type naturetic peptide (BNP), 6-minute walk test (6-MWT), and the Kansas City Cardiomyopathy Questionnaire (KCCQ) were obtained. RESULTS: BNP tended to increase in the AT-C while remaining stable in the EX over time. A clinically significant increase in 6-MWT was demonstrated by the EX but not the AT-C. The EX achieved a clinically significant change on the KCCQ at 12 weeks, with further improvement by 24 weeks, while the AT-C demonstrated a clinically significant change at 24 weeks. CONCLUSIONS: Attention alone was inadequate to positively impact BNP levels or 6-MWT distances, but did have a positive impact on quality of life after 24 weeks. Although exercise offers enhanced benefits, individuals with HF unable to participate in an exercise program may still gain quality of life benefits from participation in a peer-support group that discusses topics pertinent to HF.

Relationship of resting B-type natriuretic peptide level to cardiac work and total physical work capacity in heart failure patients.

PURPOSE: Plasma B-type natriuretic peptide (BNP) levels obtained at rest have been previously shown to be correlated with the global functional capacity measures of peak oxygen uptake (V(O(2peak))) and the minute ventilation/carbon dioxide (VE/V(O(2))) slope. The purpose of this study was to assess the relationship of the plasma BNP level to the rate-pressure product (RPP) as an indicator of central or cardiac work capacity. METHODS: Twenty-two subjects (12 men), mean age 57 +/- 12 years, diagnosed with heart failure (8 ischemic/14 nonischemic) were recruited. All subjects were stable on optimal medical therapy for at least 1 month. Blood samples for BNP level analysis were obtained at rest. Subjects underwent a symptom-limited treadmill exercise test using a ramping protocol while V(O(2)), heart rate (HR), and blood pressure (BP) were monitored. Correlation analyses were conducted to assess the relationship of BNP level to RPP level, V(O(2peak), VE/V(O(2)) slope, end-tidal CO(2) pressure (P(ET)CO(2)), and left ventricular ejection fraction (LVEF). RESULTS: Resting BNP levels were significantly correlated with RPP levels (r = -0.69). The BNP level and the RPP level were correlated with V(O(2peak)) (r = -0.63 and r = 0.66, respectively) and VE/V(O(2)) slope (r = 0.53 and r = -0.54, respectively). The RPP level but not the BNP level was correlated with P(ET)CO(2) (r = 0.57). Neither BNP nor RPP levels were well correlated with LVEF (r = -0.26 and r = 0.14, respectively). DISCUSSION: The results of this study suggest that resting plasma BNP level may be a useful clinical measure for evaluating both global functional capacity and myocardial specific work capacity in individuals with heart failure.

Staying on course: the effects of an adherence facilitation intervention on home exercise participation.

The purpose of this investigation was to test the effectiveness of an adherence facilitation intervention consisting of goal setting, graphic feedback, and provider guidance to support adherence to home exercise in a sample of patients with heart failure who had completed a supervised exercise program. The sample consisted of 13 patients with an ejection fraction of 40% or less who were randomly assigned to either the exercise only group (n=6) or the exercise with adherence facilitation group (n=7). The format of the intervention was graphic depiction of each patient's exercise goals in comparison to each patient's exercise participation. Graphs were mailed at 3-week intervals for 12 weeks. Results indicate that patients who received the intervention demonstrated higher exercise adherence and greater confidence in continuing to exercise in the future. The adherence facilitation intervention may be helpful to heart failure patients in adapting to a program of home exercise. (c)2002 CHF, Inc.