Table 5

Clinical Changes After 12 Months of Long-Term Treatment

Clinical MeasurenBefore Implantation (Baseline)12 Months of Treatmentp Value*
Oxygen uptake at peak exercise (ml/kg/min)2212.57 ± 0.6315.63 ± 0.86<0.001
Oxygen uptake at anaerobic threshold (ml/kg/min)219.93 ± 0.4611.45 ± 0.590.037
6-min walk distance (m)25357 ± 20446 ± 15<0.001
Quality-of-life score2848.6 ± 4.320.0 ± 4.1<0.001
NYHA functional class29<0.001
 IV4 (14%)0
 III25 (86%)8 (28%)
 II011 (38%)
 I010 (34%)

NYHA = New York Heart Association.

  • * All p values were derived from the paired ttest, except for NYHA functional class, which was derived from the Wilcoxon matched-pairs test. Data are presented as the mean value ± SEM or number (%) of subjects.