Exercise training improves microvascular function in patients with Chagas heart disease: Data from the PEACH study

Background: Chagas heart disease (CHD) impairs the systemic microvascular function. We investigated the effects of exercise training on cutaneous microvascular function among patients with CHD. Methods: Patients from the PEACH study were randomly assigned to a supervised exercise training 3 times/week for 6 months (Trained; n = 10) or a control group (Untrained; n = 8). Both groups underwent evaluation of microvascular function before, and at 3and 6-months of follow-up. Cutaneous vascular conductance (CVC) was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh), sodium nitroprusside (SNP) and during post-occlusive reactive hyperemia (PORH). Results: At 3-months of follow-up, no difference was detected between groups in CVC responses to ACh (p = 0.50), SNP (p = 0.26) and HRPO (p = 0.65). However, at 6-months of follow-up, trained vs. untrained patients improved CVC induced by SNP-iontophoresis (0.19 +/- 0.10 vs. 0.14 +/- 0.15 APU.mmHg(-1); p = 0.05) and PORH (0.63 +/- 0.15 vs. 0.48 +/- 0.18 APU.mmHg(-1); p = 0.05). CVC response to ACh-iontophoresis was similar between groups (0.19 +/- 0.11 vs. 0.22 +/- 0.17 APU.mmHg(-1); p = 0.38). Conclusion: Exercise training performed during 6 months improved the cutaneous microvascular function of CHD patients. Further studies evaluating the mechanism involved in this response are warranted.