Efeito da estimulação transcraniana por corrente contínua associada ao treinamento aeróbio em pacientes com insuficiência cardíaca na capacidade física e perfil inflamatório: um ensaio clínico controlado, randomizado e duplo cego

Abstract

Heart failure with reduced ejection fraction (HFrEF) involves significant functional limitation, neurohumoral activation, and persistent systemic inflammation. Aerobic training is a consolidated therapy in cardiovascular rehabilitation, while transcranial direct current stimulation (tDCS) emerges as a potential adjuvant neuromodulatory strategy to influence cortical circuits associated with autonomic control and fatigue. This study aimed to evaluate the effects of tDCS combined with aerobic training on the physical-functional capacity and inflammatory profile of patients with HFrEF. This was a randomized, controlled, double-blind clinical trial involving 19 participants allocated into the tDCS (n=9) or sham (n=10) groups, who underwent 12 intervention sessions combining supervised aerobic training on a cycle ergometer. Functional capacity was evaluated by the 6-Minute Walk Test (6MWT). Inflammatory cytokines (IL-1β, IL-6, IL-10, and TNF-α) were quantified using Cytometric Bead Array (CBA). Physical capacity and metabolic efficiency were assessed via a symptom-limited Cardiopulmonary Exercise Test (CPET), and quality of life by the Minnesota Living with Heart Failure Questionnaire (MLHFQ). Statistical analysis followed the intention-to-treat principle, exhibiting baseline homogeneity. Post-intervention, the tDCS group demonstrated a 26.09% increase in the 6MWT distance (440.8±105.6 m to 555.8±155.8 m; Δ+115.0±100.0 m), whereas the sham group remained virtually unchanged. In the CPET, peak metabolic and ventilatory variables remained unaltered and homogeneous. Regarding the inflammatory profile, no widespread systemic modifications were observed, identifying only a selective and significant reduction in TNF-α levels in the tDCS group, with no changes in the remaining cytokines or their ratios. Quality of life improved in both arms, with a reduction in MLHFQ scores in the tDCS (56.33±23.41 to 31.67±29.10) and sham (51.60±28.30 to 24.70±20.95) groups, showing no intergroup differences. The association between tDCS and aerobic training promoted an improvement in submaximal functional capacity, with an inflammatory impact restricted to TNF-α and without additional benefits in quality of life or maximum metabolic ceiling. The findings suggest that tDCS acts as a promising adjuvant strategy in optimizing exercise response and effort tolerance in HFrEF.