Cardiac Evaluation in the Acute Phase of Chagas’ Disease with Post-Treatment Evolution in Patients Attended in the State of Amazonas, Brazil

Abstract Background: In the past two decades, a new epidemiological profile of Chagas’ disease (CD) has been registered in the Brazilian Amazon where oral transmission has been indicated as responsible for the increase of acute cases. In the Amazonas state, five outbreaks of acute CD have been registered since 2004. The cardiac manifestations in these cases may be characterized by diffuse myocarditis, with alteration in the electrocardiogram (ECG) and transthoracic echocardiogram (TTE). Objective: To perform a cardiac evaluation in autochthonous patients in the acute phase and at least one year after submitted to treatment for acute CD and evaluate the demographic variables associated with the presence of cardiac alterations. Methods: We evaluated patients diagnosed with acute CD through direct parasitological or serological (IgM) methods from 2007 to 2015. These patients were treated with benznidazole and underwent ECG and TTE before and after treatment. We assumed a confidence interval of 95% (CI 95%, p < 0.05) for all variables analyzed. Results: We observed 63 cases of an acute CD in which oral transmission corresponded to 75%. Cardiac alterations were found in 33% of the cases, with a greater frequency of ventricular repolarization alteration (13%), followed by pericardial effusion (10%) and right bundle branch block and left anterior fascicular block (2%). The follow-up occurred in 48 patients with ECG and 25 with TTE for a mean period of 15.5 ± 4.1 months after treatment. Of these, 8% presented normalization of the cardiac alterations in ECG, 62.5% remained with the normal exams. All of the patients presented normal results in TTE in the post-treatment period. As for the demographic variables, isolated cases presented more cardiac alterations than outbreaks (p = 0.044) as well as cases from Central Amazonas mesoregion (p = 0.020). Conclusions: Although cardiac alterations have not been frequent in most of the studied population, a continuous evaluation of the clinical-epidemiological dynamics of the disease in the region is necessary in order to establish preventive measures.

摘要 背景：近二十年来，巴西亚马逊地区出现了新的恰加斯病（Chagas’ disease）流行病学特征，经口传播被证实为急性病例数上升的主要诱因。自2004年以来，亚马孙州已报告5起急性恰加斯病暴发事件。此类病例的心脏表现可呈现弥漫性心肌炎，伴随心电图（electrocardiogram, ECG）与经胸超声心动图（transthoracic echocardiogram, TTE）异常。

目的：对急性恰加斯病急性期的本土患者，以及接受治疗至少1年后的患者开展心脏评估，并分析与心脏异常相关的人口学变量。

方法：本研究纳入2007年至2015年间，通过直接病原学或血清学（IgM）检测方法确诊为急性恰加斯病的患者。所有患者均接受苄硝唑治疗，并在治疗前后完成ECG与TTE检查。本研究所有分析变量均采用95%置信区间（CI 95%，p < 0.05）进行统计检验。

结果：本研究共纳入63例急性恰加斯病病例，其中经口传播占比75%。33%的病例存在心脏异常，以心室复极异常最为常见（13%），其次为心包积液（10%），以及右束支传导阻滞合并左前分支阻滞（2%）。48例患者完成了治疗后ECG随访，25例完成了TTE随访，平均随访时长为15.5±4.1个月。其中8%的患者ECG提示心脏异常恢复正常，62.5%的患者检查结果仍为正常；治疗后所有患者的TTE结果均恢复正常。就人口学变量而言，散发病例的心脏异常发生率高于暴发疫情病例（p=0.044），来自亚马孙州中部中地区域的病例心脏异常发生率也更高（p=0.020）。

结论：尽管本次研究的多数受试者未出现频发心脏异常，但仍需持续评估该地区恰加斯病的临床-流行病学动态，以制定针对性预防措施。