Influence of creatine supplementation on the functional capacity of patients with heart failure.

Heart failure (HF) is a complex syndrome characterized by intolerance to exertion and reduced functional capacity. To assess the functional capacity of patients with HF and supplemented with creatine. Prospective, randomized, double-blind study. Thirty-three male patients over the age of 18 years with functional class II to IV HF were randomized into two groups as follows: the experimental group (CRE, n = 17), supplemented with 5 g/day of creatine for six months; and the placebo group (PLA, n = 16), receiving 5 g/day of maltodextrin for that same period. Both groups underwent functional capacity assessment by use of cardiopulmonary exercise test and 6-minute walk test (6MWT) before and after the intervention. The Ancova statistical model and Pearson correlation were used to assess the groups and the treatment. Of the variables assessed on the cardiopulmonary exercise test, peak oxygen consumption (peak VO₂), anaerobic threshold (AT), and oxygen pulse (O₂ pulse) showed no significant differences between the groups (P>0.05). On the 6MWT, no significant difference was observed in the covered distance. Creatine supplementation in patients with HF did not significantly improve functional capacity.