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

Abstract

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.

Keywords: attention; exercise; heart failure.

Figure 1

Boxplot depicting the Heart Camp and Attention Control Groups % Change in BNP. The bottom and top of the box are the 25^th and 75^th percentile (the lower and upper quartiles, respectively), and the dark line within the box represents the 50^th percentile (median). The ends of the whiskers indicate the lowest datum still within 1.5 times the interquartile range of the lower quartile, and the highest datum still within 1.5 times the interquartile range of the upper quartile. Circles indicate outliers with values between 1.5 and 3 boxlengths outside the box. Stars indicate extreme values > 3 box lengths outside the box. The upper dashed reference line at 140% indicates a clinically important decline and lower dashed reference line at −70% indicates a clinically important improvement.

Figure 2

Boxplot depicting the Heart Camp and Attention Control Groups Change in 6-Minute Walk Test. The bottom and top of the box are the 25^th and 75^th percentile (the lower and upper quartiles, respectively), and the dark line within the box represents the 50^th percentile (median). The ends of the whiskers indicate the lowest datum still within 1.5 times the interquartile range of the lower quartile, and the highest datum still within 1.5 times the interquartile range of the upper quartile. Circles indicate outliers with values between 1.5 and 3 boxlengths outside the box. The dashed reference lines at +/− 50 meters represent clinically important improvement or decline.

Figure 3

Boxplot depicting the Heart Camp and Attention Control Groups Change in KCCQ Total Score. The bottom and top of the box are the 25^th and 75^th percentile (the lower and upper quartiles, respectively), and the dark line within the box represents the 50^th percentile (median). The ends of the whiskers indicate the lowest datum still within 1.5 times the interquartile range of the lower quartile, and the highest datum still within 1.5 times the interquartile range of the upper quartile. Circles indicate outliers with values between 1.5 and 3 boxlengths outside the box. Stars indicate extreme values > 3 box lengths outside the box. The dashed reference lines at +/− 5 points represent clinically important improvement or decline.