ABC | Volume 112, Nº3, March 2019

Original Article Ortiz et al Cardiac evaluation in acute CD Arq Bras Cardiol. 2019; 112(3):240-246 fruits and meat of wild mammals. 3,17,18 In the last two decades, many new oral transmissions related acute cases have been registered with six outbreaks in the state of Amazonas 5,19-21 and T. cruzi DTU described to be related to these cases are TcIV and Z3 (TcIII/TcIV). 21,22 Although in the Brazilian Amazon region CD has been widely studied, in the state of Amazonas there still are few data regarding the epidemiological profile of acute CD and more importantly, works related to the cardiac manifestations and post-treatment follow-up are scarce in this group of patients. For that matter, this work aimed to describe cardiac alterations in autochthones patients who had acute CD at least one year after submitted to treatment with benznidazole. Methods This was a longitudinal study of patients attended at the Francisca Mendes University Hospital for cardiac follow-up. All of these patients have a confirmed diagnosis of acute CD at the Tropical Medicine Foundation Dr Heitor Vieira Dourado, from January of 2007 to July of 2015. Study population Patients were included considering the following criteria: a positive laboratory exam, direct parasitological test (thick blood smear or natural xenodiagnosis) or a reactive immunological essay (IgM anti- T. cruzi ) (Enzyme-linked immunoassay – ELISA and/or indirect immunofluorescence assay– IFA) with an epidemiological history such as being originally from the Brazilian Amazon region. All patients were excluded if they referred any previous travel to another Brazilian region or foreign country, did not adhere to or had an incomplete treatment. Procedures for data collection and treatment Cardiological exams, standard12-leadelectrocardiogram(ECG) and transthoracic echocardiogram (TTE), was analyzed before treatment and at least one year after the end of treatment. In order to obtain data of patients in pre-treatment stage, a retrospective analysis was made of cases registered in the electronic medical record iDoctor  from 2007 to 2015 in order to access the results of the ECG and TTE as well as demographical, epidemiological and clinical data. During the stage of post‑treatment, a prospective evaluation was made which included a clinical examination and performing ECG and TTE in all patients. The standard 12-lead ECG tracing was done using the software Wincardio (Micromed) and the TTE was performed following the recommendations of the American Society of Echocardiography, using the GE, Vivid 3 equipment. All patients underwent treatment with benznidazole (Rochagan  ) 5-7 mg/kg, for 60 days according to the II Brazilian Guidelines in Chagas Disease of 2015. 23 And any cardiac alteration in the ECG or TTE was considered for the description as cardiac alterations in the acute phase of CD. Statistical analysis Clinical and epidemiological data were organized using Excel 2016 and the analysis was done using Stata/MP 13.0 . For categorical variables, Fisher’s exact test was used and the results are presented in tables of absolute and relative frequencies followed by the corresponding p-value. For continuous variables, normal distribution was tested using Shapiro-Wilk normality test, if the normal distribution was observed, an unpaired t-test (Student t-test) was executed and results presented by mean ± SD, otherwise, the Wilcoxon rank-sum (Mann-Whitney) test was used and the results are presented by median and interquartile intervals. We assumed a confidence interval of 95% (CI 95%, p < 0.05) for all statistical tests. Ethical consideration This study was approved by the Research Ethics Committee of the Universidade do Estado do Amazonas and is in agreement with the Resolution 466/12 of the Brazilian National Health Council (approval number 923.701/2014). Results Case distribution, route of transmission and T. cruzi strain During the study period, 63 patients with confirmed acute CD were evaluated, all originally from the state of Amazonas. The diagnosis was 98% by a direct parasitological method, thick blood smear. The median age was 29 [16-44] years old, predominantly male (60%). Of these, 44 (70%) were part of an outbreak that was registered from 2007 to 2015, the other 19 (30%) cases are distributed between isolated acute cases associated with oral transmission or classical vector transmission. There were more registered cases of cardiac alterations in the isolated cases reported then in the outbreaks (48% vs. 21%, p = 0.044). A wide distribution of acute cases is best shown in Figure 1, there can be noticed that most municipalities of the Central Amazonas mesoregion are affected. On the other hand, the Southwest mesoregion concentrated the higher frequency of acute cases corresponding to 33 (53%) cases, and 31 of them being from the outbreaks that happened in Carauari in 2011 and 2015. Cardiac alterations were present in 69% in the Central Amazonas mesoregion which represented a statistical significance (p = 0.020). With regards to the strains of T. cruzi, it was possible to isolate in 35 cases (56%) of which 22 (63%) were Z3 (TcIII/ TcIV) and 11 (31%) were TcIV and 2 (6%) TcI, both Z3 (TcIII/ TcIV) and TcIV associated with acute oral transmission from outbreaks (Table 1). Cardiac evaluation in Group 1 (pre-treatment) We observed 33% of any cardiac alterations in our study population. All 63 patients had an ECG prior to initiate the standard treatment with benznidazole. Of these, 44 (70%) presented normal results. Yet, abnormalities such as ventricular repolarization alterations were common. Regarding the TTE results, 87% presented normal parameters. (Table 2). Although the majority of our population presented normal exams, it is noteworthy the death of a three-month-old infant due to severe cardiac condition. 241