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

BACKGROUND: Heart failure (HF) is a complex syndrome characterized by intolerance to exertion and reduced functional capacity. OBJECTIVE: To assess the functional capacity of patients with HF and supplemented with creatine. METHODS: 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. RESULTS: 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. CONCLUSION: Creatine supplementation in patients with HF did not significantly improve functional capacity.