ABC | Volume 112, Nº3, March 2019

Original Article Ortiz et al Cardiac evaluation in acute CD Arq Bras Cardiol. 2019; 112(3):240-246 Table 1 – Baseline characteristics of acute Chagas’ disease patients treated with benznidazol Group Variable Total (n = 63) Cardiac alterations (n = 21) No Cardiac alterations (n = 42) p-value Age (y) 29 [16-44] 38 [15-44] 26.5 [17-44] 0.694* Gender 0.588† Male 38 (60%) 14 (67%) 24 (57%) Female 25 (40%) 7 (33%) 18 (43%) Transmission 0.364† Oral 47 (75%) 14 (67%) 33 (79%) Vector 16 (25%) 7 (33%) 9 (21%) Case 0.044† Outbreak 44 (70%) 11 (52%) 33 (79%) Isolated 19 (30%) 10 (48%) 9 (21%) Origin (Mesoregion) 0.020† Central Amazonas 13 (21%) 9 (43%) 4 (10%) North Amazonas 15 (24%) 3 (14%) 12 (29%) Southwest Amazonas 33 (53%) 9 (43%) 24 (59%) South Amazonas 1 (2%) - 1 (2%) T. cruzi DTU 0.355† TcI 2 (3%) 2 (9%) - TcIV 11 (17%) 2 (9%) 9 (21%) Z3 (TcIII/TcIV) 22 (35%) 9 (43%) 13 (31%) ND 28 (44%) 8 (38%) 20 (48%) Follow-up period (y) 15.5 ± 4.1 14 ± 4 16.4 ± 4.1 0.050** Data are expressed as median [IQ25%-IQ75%] and mean ± SD; In parenthesis are the percentage of the total group; ND: not described; Obs.: It was not possible to obtain the provenance of one case. *Wilcoxon rank-sum (Mann-Whitney) test. **Unpaired t-test (Student t test). † Fisher’s exact test. due to the location of state’s capital, Manaus, the number of cardiopathy cases in Manaus was very low (n = 4). Also, higher frequency of cardiopathy reported in isolated acute cases (48%) might suggest a possible association either by oral or classical vector transmission with the strain of the protozoan, for which TcI was already found in all isolated cases of CD, associated to chronic CD and Chagas cardiomyopathy. 27,28 And the strain TcIV has been reported in outbreaks. 21 But this association is not possible to affirm considering the low number of patients with identified strain of the parasite. During cardiac evaluation of the acute phase, most of the patients presented normality in both ECG or TTE examination. In the post-treatment period, we observed that most of the patients evolved to a normal result in the cardiological examinations. Pericardial effusion resolved very well, but ventricular repolarization alteration remained in four patients even after treatment. A factor that has been reported in other follow-up examination of acute cases to be undefined due to an unfamiliarity of a predictor parameter of cure. 6,13,14 Cardiac alterations in the state of Amazonas are not frequent, but the knowledge is still scarce regarding the whole transmission dynamic and possible influences in a long-term period. Acute cases reported in the neighboring state of Pará presented serious cardiac involvement, with three died due to severe myocarditis, renal failure and cardiac tamponade. 19 In a study carried out by Ferreira et al. 29 in the Amazon region, five cases were reported of which two were from Pará and three from Amazonas, all of them presented reversed cardiac alterations and no deaths. In this study, one death was registered in a three-month-old infant, who presented a cardiogenic shock and meningoencephalitis due vector transmission with the presence of chagoma, a localized swelling at the site of inoculation. This remarkable difference suggests that the clinical manifestations and mortality is lower in the state of Amazonas, though is unknown the reason. Study limitations This was a unicentric longitudinal study, with a small study population and most of the participants living in the countryside of the state. These factors didn’t allow a complete follow-up, contributing to a loss of patients. Also, it was possible to obtain the strains of the parasite only from patients that were recruited more recently, which limited the genetic characterization. 243