Selenium, TGF-Beta and Infectious Endemic Cardiopathy: Lessons from Benchwork to Clinical Application in Chagas Disease.

For over 60 years, selenium (Se) has been known as an essential microelement to many biological functions, including cardiovascular homeostasis. This review presents a compilation of studies conducted in the past 20 years related to chronic Chagas disease cardiomyopathy (CCC), caused by Trypanosoma cruzi infection, a neglected disease that represents a global burden, especially in Latin America. Experimental and clinical data indicate that Se may be used as a complementary therapy to prevent heart failure and improve heart function. Starting from the main questions "Is Se deficiency related to heart inflammation and arrhythmogenesis in CCC?" and "Could Se be recommended as a therapeutic strategy for CCC?", we show evidence implicating the complex and multidetermined CCC physiopathology, discussing its possible interplays with the multifunctional cytokine TGF-ß as regulators of immune response and fibrosis. We present two new proposals to face this global public health challenge in vulnerable populations affected by this parasitic disease: fibrosis modulation mediated by TGF-ß pathways and the possible use of selenoproteins as antioxidants regulating the increased reactive oxygen stress present in CCC inflammatory environments. We assess the opportunity to consider the beneficial effects of Se in preventing heart failure as a concept to be applied for CCC patients.

Effects of Selenium treatment on cardiac function in Chagas heart disease: Results from the STCC randomized Trial.

BACKGROUND: Chagas disease (caused by Trypanosoma cruzi infection) evolves to chronic chagasic cardiomyopathy (CCC) affecting 1.8 million people worldwide. This is the first randomized, placebo-controlled, double-blinded, clinical trial designed to estimate efficacy and safety of selenium (Se) treatment in CCC. METHODS: 66 patients with CCC stages B1 (left ventricular ejection fraction [LVEF] > 45% and no heart failure; n = 54) or B2 (LVEF < 45% and no heart failure; n = 12) were randomly assigned to receive 100 mcg/day sodium selenite (Se, n = 32) or placebo (Pla, n = 34) for one year (study period: May 2014-September 2018). LVEF changes over time and adverse effects were investigated. Trial registration number: NCT00875173 (clinicaltrials.gov). FINDINGS: No significant differences between the two groups were observed for the primary outcome: mean LVEF after 6 (ß= +1.1 p = 0.51 for Se vs Pla) and 12 months (ß= +2.1; p = 0.23). In a subgroup analysis, statistically significant longitudinal changes were observed for mean LVEF in the stage B2 subgroup (ß= +10.1; p = 0.02 for Se [n = 4] vs Pla [n = 8]). Se treatment was safe for CCC patients, and the few adverse effects observed were similarly distributed across the two groups. INTERPRETATION: Se treatment did not improve cardiac function (evaluated from LVEF) in CCC. However, in the subgroup of patients at B2 stage, a potential beneficial influence of Se was observed. Complementary studies are necessary to explore diverse Se dose and/or associations in different CCC stages (B2 and C), as well as in A and B1 stages with longer follow-up. FUNDING: Brazilian Ministry of Health, Fiocruz, CNPq, FAPERJ.

Effects of omega-3 polyunsaturated fatty acid supplementation in patients with chronic chagasic cardiomyopathy: study protocol for a randomized controlled trial.

BACKGROUND: Chronic chagasic cardiomyopathy is an inflammatory disease that occurs in approximately 30% of patients infected by the protozoan Trypanosoma cruzi, and it has a profile of high morbidity and mortality. The worst prognosis and the progression of this cardiomyopathy are associated with an exacerbated immune response and the production of proinflammatory cytokines, which also occur in other cardiomyopathies. Some nutrients, including omega-3 polyunsaturated fatty acids (PUFAs), promote the inhibition and/or stimulation of cytokine production. The objective of this trial is to study the effects of omega-3 PUFA supplementation on the inflammatory response and lipid profile in patients with chronic chagasic cardiomyopathy. METHODS/DESIGN: This is a parallel, randomized, placebo-controlled, double-blind clinical trial with 40 patients that will be conducted at a reference unit for Chagas disease patients, where the patients will be selected. The study will include patients with chronic chagasic cardiomyopathy who are 18 years of age or older. The exclusion criteria are (a) ongoing diarrheal disease, (b) inflammatory bowel disease, (c) diabetes or other endocrine disease, (d) use of fibrates, niacin, or statins, (e) use of anti-inflammatory drugs, (f) pregnant and lactating women, (g) use of vitamin, mineral, or omega-3 supplementation during the previous 30 days, (h) hospital admission during the study, and (i) other associated cardiomyopathies. The intervention will be treatment with omega-3 PUFAs at a dose of 3 g/day for 8 weeks, compared to placebo (corn oil). The primary endpoints will be the concentrations of inflammatory markers (interleukin (IL)-1, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)α, interferon (IFN)γ, and transforming growth factor (TGF)ß). Secondary endpoints will be the fasting glucose, lipid, and anthropometric profiles. For statistical analysis, we plan to run either a t test or Wilcoxon test (numerical variables) and Pearson's χ2 or Fisher's exact test (categorical data), as appropriate. DISCUSSION: Evidence suggests that the anti-inflammatory action of omega-3 PUFAs may have beneficial effects on chronic chagasic cardiomyopathy, as shown for other cardiomyopathies, due to improved control of the inflammatory response. At the end of the study, we predict that patients will have lower inflammatory markers and an improved metabolic and anthropometric profile. TRIAL REGISTRATION: Current Controlled Trials NCT01863576.