A randomized trial of the effects of exercise training in Chagas cardiomyopathy

Abstract

Aims: The effects of exercise training in chronic heart failure are well established, however, they have not been evaluated in Chagas cardiomyopathy (ChC). We sought to determine the effects of exercise training on functional capacity, health-related quality of life (HQoL), and brain natriuretic peptide (BNP) levels in patients with ChC.

Methods and results: This randomized, controlled, single-blind trial included 40 patients with ChC (age 49.5 +/- 7.8 years, 57.5% male) who did not practice regular exercise. All patients were assessed, at baseline and at the end of the study, by exercise test (VO(2) and exercise time), six-minute walk test (6MWT), Goldman Specific Activity Scale (SAS), HQoL, and BNP levels. Patients were randomized to inactive control group (ICG = 19) or exercise training group (ETG = 21). Exercise training group patients underwent 12 weeks of exercise training: walking for up to 30 min (intensity 50-70% HR reserve + HR at rest) and warm-up and cooling-down exercising, three times a week. The data were analysed for delta values (Delta= end - baseline). After intervention, compared with the ICG, the ETG had significant increases in functional parameters including, DeltaVO(2) (6.5 vs. 2.8 mL/kg/min, P = 0.001), Delta exercise time (2.9 vs.1.1 min, P < 0.001), Delta6MWT distance (83.5 vs. 2.0 m, P = 0.001) improved DeltaSAS (8 vs. 1 patient, P = 0.008), and HQoL: Delta domains vitality (7.5 vs. 0 points, P = 0.013), Delta emotional aspects (16.7 vs. 0 points, P = 0.012), and Delta mental health (16.1 vs. 0 points, P = 0.031). There was no difference in BNP levels.

Conclusion: In patients with ChC, exercise training was associated with a major improvement in functional capacity and HQoL without any adverse effects.