**4. Timeline of selenium treatment in Chagas Cardiopathy (STCC) clinical trial, the strength of a scientific network and the social arm of the project**

The next step, in 1999, was to enhance the number of patients studied to confirm whether Se levels would be lower in patients with more severe cardiac disease. The first partnership was made with Dr. Alejandro M. Hasslocher-Moreno, who was the physician responsible for the clinic management and follow-up of CD patients at the Evandro Chagas National Institute of Infectious Diseases (INI), Fiocruz, Rio de Janeiro city. Se levels were measured and a very large variation was observed. We then decided that patients with different nutritional habits from another state in Brazil should also be analyzed. It implicated a new partnership with colleagues from Belo Horizonte city and CD patients from Dr. Manoel Otávio Rocha, enrolling a total of 273 patients in the study [4]. We observed that Se levels in patients with moderate and severe cardiopathy were lower than in patients with mild cardiopathy and indeterminate form, as well as in uninfected individuals [4].

In parallel, we performed some proof-of-concept studies, showing in experimentally *T. cruzi*-infected mice—(i) that Se diet deficiency turn mice much more susceptible to acute-phase mortality [1]; (ii) the parasite survival and replication was not affected by Se [2]; (ii) that mice parasitemia did not vary in situations of nutritional deficiency or Se supplementation [2]; (iii) that in the acute [2] and in the chronic [3] phases in mice, treatment with Se was able to reduce cardiac inflammation, regulate arrhythmias, and prevent cardiomegaly; (iv) digestive mega disease was prevented by Se supplementation [22]. A second idea was planted—could Se treatment or supplementation prevent the progression of chronic forms of CCC?

In 2004, we started to move on to the clinical trials stage. We designed a placebo-controlled, double-blind trial, recruiting patients with mild heart disease (stages B1 and B2 defined by the Brazilian Consensus on CD) followed at the Chagas clinic at INI-Fiocruz, for treatment of 100 mcg/day Se for 1 year. Two outcomes were defined—50% reduction in progression of heart disease and a significant reduction in left ventricular ejection fraction (LVEF) value in 5 years of follow-up. However, we did not previously contact a Se supplier. Our first impediment was to think that it should be easy to find a Se source in the Brazilian pharmaceutical market. The saga was in the early beginning. **Figure 2** represent the

historical saga of the Se clinical trial, including the first step (1996–2004 period) of developing ideas, hypothesis, and pre-clinical studies.


*The Saga of Selenium Treatment Investigation in Chagas Disease Cardiopathy: Translational… DOI: http://dx.doi.org/10.5772/intechopen.103772*

(x) Immunological analyzes (humoral and cellular); (xi) Nutritional assessment; (xii) Follow-up ECG and ECO; (xiii) Follow-up echocardiogram. A challenge was the complexity of dealing with so many fields, multiplied by 135 expected participating patients multiplied by 14 visits each, with 10 only in the first year. It resulted in 1890 visits, with all the variables and biomarkers collected in most of them. In 2014, we had overcome the main obstacles to crossing the "valley of death," as shown in Declan Butler's publication in *Nature* in 2008 [23], and we the first patient was enrolled, enabling the publication of the STCC trial protocol in 2014 [24]. But then…


At this point, we decided to develop what we call the social arm of the clinical project.

April 14, 2015, we organized a meeting to make a public launch of the project, and to propose workshops of playful activities to "Talk about Chagas with Science and Art," inspired by the work of the Argentine group "Hablamos de Chagas" [29]. These initiatives quickly produced results—(i) we organized five successive editions of the course "We talk about Chagas with Science and Art" from 2015 to 2019, for people with CD, their family members, and health professionals; (ii) we created a

#### **Figure 3.**

*Time sequence of inclusion of participants on the STCC clinical trial. Black solid line shows the putative participants tracked, dashed line shows the participants included after signing the project voluntary consent form, and solid line with white dots shows the number of patients that completed the one-year treatment. Note that after 2015 the slope angle of the inclusion curve rise, denoting a success in the recruiting phase.*

"Rio Chagas Collective" on social media, which gave rise to the (iii) "Rio Chagas Association," founded on April 8, 2016, in which we participate in the Scientific Council; and (iv) the Rio Chagas Association participants inspired us to conceive the "Chagas Express XXI" social technology [30].

13. In 2018, we created a *YouTube* channel called "We talk about Chagas" (https:// www.youtube.com/c/FalamosdeChagas) to provide videos about Chagas disease, and in 2019, we created the social technology for those affected by the disease named "Expresso Chagas XXI" to talk about Chagas in endemic areas, bringing science, culture, and art to those most in need of information for health promotion, prevention of Chagas disease and access to diagnosis and treatment in the Unified Health System (SUS – Sistema Único de Saúde). In 2019, we carried out a pilot expedition in four cities in an endemic area for CD in northern Minas Gerais. In addition, in 2020, we organized solidarity strategies for coping with the COVID-19 pandemic together with Rio Chagas Association (virtual WhatsApp meetings called "Coffee with Affection").

Chagas Express XXI was created as an "imaginary train" with around 40 ArtScience workshops, games, laboratory activities, and conversation circles. It was structured with an entry and exit point, followed by six more modules of activities that combined a focus on associations of affected people, on opportunities for the public to rediscover Carlos Chagas' discoveries, on microscopic observations and play, on health education in approach. A One Health approach was adopted, with a focus on home care, environment and reservoirs, and wellness activities. Chagas Express XXI was conceived as a social technology since all processes were co-created by scientists and patients with Chagas disease and worked with local cross-sector partnerships. We observed that 81% of the more than 2000 participants were unaware of the possibility of treating Chagas disease and 52% requested a blood test to diagnose CD. From the 1100 adults tested, 20% were diagnosed as positive for *T. cruzi* infection [30].

The fourth idea would then be: if the clinical trial of Se becomes unfeasible, we will have a social legacy to be able to continue later.

14. However, the problem was not only in the communication and mobilization of patients to participate in STCC, since in INI/Fiocruz cohort the number of patients *The Saga of Selenium Treatment Investigation in Chagas Disease Cardiopathy: Translational… DOI: http://dx.doi.org/10.5772/intechopen.103772*

in the B1 and B2 stages of CCC was small as compared to patients in other clinical stages (indeterminate, A and C/D). Besides, a new risk for the project was arising: a long time had passed and the patients in the INI/Fiocruz cohort aged, acquiring comorbidities that were predicted as exclusion criteria and entering other studies that were ongoing, almost making the trial unfeasible due to a very slow rate of inclusion, as shown in **Figure 3**, during the years 2016 and 2017. To overcome this problem, the clinicians proposed to increase the age of recruitment from 65 to 75 years and to consider diabetes mellitus as a non-exclusion criterion.

Besides, the statisticians carried out other scenario studies for the feasibility of the STCC. They concluded that by extending the age range to up to 75 years, reducing the time of follow-up to one year, and focusing as a primary outcome only on the reduction of LVEF values (and not on the rate of CCC progression), we would conclude the inclusion of participants and generate some valid results. Then, in 2018, we published an update of the protocol [31] and started working to include 62 patients, divided into the two groups (placebo and Se treatment) for a follow-up of one year. We were then able to include all the expected patients and on August 8th, 2018, we were able to complete the last 12 months' visit of the last participant included.

15. The next step was to include all the laboratory and the nutritional data in the database, to run quality control for it, and to start the statistical analysis, both for descriptions of the clinical findings of participants and for comparisons between the placebo and Se-treated groups, as well as sub-group analyses, whenever possible. The study results were finally published in September 2021 [5]. When comparing the mean values of LVEF recorded in Se treated with the placebo group at baseline and after 1 year of follow-up, we did not find significant differences in the B1/B2 stages patients (overall), nor in the B1 stage patients, but found a significant effect (*p* = 0.02) in the B2 stage patients (**Figure 4**).

After one year (**Figure 4**, gray bars), all the groups showed a lower mean of LVEF when compared to baseline values (**Figure 4**, black bars). However only those already on the B2 subgroup, with LVEF <45%, showed a high decrease in LVEF in 1-year, which

#### **Figure 4.**

*Mean values for left ventricular ejection fraction recorded for all the patients participating in the STCC clinical trial, at baseline (baseline, black bars) and after 12 months (gray bars). In the X-axis it is shown the comparison of the groups treated with placebo or selenium, considering all the participants in each group and in the subgroups B1 and B2 stages. For details, see reference #5. Figure 4 Was prepared with data published in the STCC results [5].*

was reversed by Se treatment. The differences in LVEF longitudinal changes between groups were evaluated using linear mixed effect models in intention-to-treat analyses. This type of analysis assesses the rate of change of the outcomes by the time X intervention group interaction term, considering the correlations between repeated measures over time and missing data. In the B2 subgroup, the worsening of cardiac dysfunction was significantly reduced by Se treatment, and while the placebo group had a drop in LVEF, the Se group remained stable. In addition, only in the Se group, we observed cases of LVEF increase of more than 10 absolute points in 5 patients (n = 3) and recovery from stage B2 to B1 (n = 2), as reported [5]. In this short-term follow-up (1 year), the secondary outcomes observed were all related to LVEF as the underlying cause and could not be weighted in the analysis. We also observed that treatment with Se was safe for patients with CCC and that the low percentage of adverse effects detected were similar in the two groups. However, there was no complete shift of patients treated with Se to a safe range of serum Se (>100mcg/L), indicating that the dose of 100 mcg per day may have been insufficient. Further studies are needed to explore higher doses and/or associations of Se at different stages of CCC (B2 and C) at a short follow-up (one year) and at early diseases stages (A and B1), with longer follow-up.

16. The paper with STCC results [5] discussed some possibilities and pointed that "new clinical trials with a longer follow-up are needed to investigate the effects of Se in the mild (stages A and B) or severe (stages C and D) CCC, and in the asymptomatic indeterminate clinical form". The limitations of STCC were reported and the future outspread of the project is depicted in **Figure 2** from 2022 to, at least, 2026. The design of new projects (STCC#2 and STCC#3) is underway, and when the adequate industry partnership(s) will be signed, the proposal is that the new clinical trials will have a following of 3 to 10 years to generate the necessary evidence to support public policies recommendations.
