Recommendations for Multimodality Cardiac Imaging in Patients with Chagas Disease: A Report from the American Society of Echocardiography in Collaboration With the InterAmerican Association of Echocardiography (ECOSIAC) and the Cardiovascular Imaging Department of the Brazilian Society of Cardiology (DIC-SBC)

A Modified Classification Scheme for Chagas Cardiomyopathy Incorporating Cardiac Magnetic Resonance Imaging

The public health concerns from Chagas disease warrant improved cardiovascular imaging efforts, and in this report, we review a military service member presenting with electrocardiographic and cardiac magnetic resonance imaging (CMR) findings that recognized a Chagas dilated cardiomyopathy. We present an updated Chagas staging classification incorporating CMR to increase diagnosing cardiomyopathies.

Impact of an online course on enhancing the diagnosis of Chagas disease in Latin America

Objective

Chagas disease poses a public health problem in Latin America, and the electrocardiogram is a crucial tool in the diagnosis and monitoring of this pathology. In this context, the aim of this study was to quantify the change in the ability to detect electrocardiographic patterns among healthcare professionals after completing a virtual course.

Materials and Methods

An asynchronous virtual course with seven pre-recorded classes was conducted. Participants answered the same questionnaire at the beginning and end of the training. Based on these responses, pre and post-test results for each participant were compared.

Results

The study included 1656 participants from 21 countries; 87.9% were physicians, 5.2% nurses, 4.1% technicians, and 2.8% medical students. Initially, 3.1% answered at least 50% of the pre-test questions correctly, a proportion that increased to 50.4% after the course (p=0.001). Regardless of their baseline characteristics, 82.1% of course attendees improved their answers after completing the course.

Conclusions

The implementation of an asynchronous online course on electrocardiography in Chagas disease enhanced the skills of both medical and non-medical personnel to recognize this condition.

Chagas cardiomyopathy in Boston, Massachusetts: Identifying disease and improving management after community and hospital-based screening

BACKGROUND

Limited data exist regarding cardiac manifestations of Chagas disease in migrants living in non-endemic regions.

METHODS

A retrospective cohort analysis of 109 patients with Chagas disease seen at Boston Medical Center (BMC) between January 2016 and January 2023 was performed. Patients were identified by screening and testing migrants from endemic regions at a community health center and BMC. Demographic, laboratory, and cardiac evaluation data were collected.

RESULTS

Mean age of the 109 patients was 43 years (range 19-76); 61% were female. 79% (86/109) were diagnosed with Chagas disease via screening and 21% (23/109) were tested given symptoms or electrocardiogram abnormalities. Common symptoms included palpitations (25%, 27/109) and chest pain (17%, 18/109); 52% (57/109) were asymptomatic. Right bundle branch block (19%, 19/102), T-wave changes (18%, 18/102), and left anterior fascicular block (11%, 11/102) were the most common electrocardiogram abnormalities; 51% (52/102) had normal electrocardiograms. Cardiomyopathy stage was ascertained in 94 of 109 patients: 51% (48/94) were indeterminate stage A and 49% (46/94) had cardiac structural disease (stages B1-D). Clinical findings that required clinical intervention or change in management were found in 23% (25/109), and included cardiomyopathy, apical hypokinesis/aneurysm, stroke, atrial or ventricular arrhythmias, and apical thrombus.

CONCLUSIONS

These data show high rates of cardiac complications in a cohort of migrants living with Chagas disease in a non-endemic setting. We demonstrate that Chagas disease diagnosis prompts cardiac evaluation which often identifies actionable cardiac disease and provides opportunities for prevention and treatment.

Use of PET/CT to detect myocardial inflammation and the risk of malignant arrhythmia in chronic Chagas disease

BACKGROUND

Chagas heart disease (CHD) is characterized by progressive myocardial inflammation associated with myocardial fibrosis and segmental abnormalities that may lead to malignant ventricular arrhythmia and sudden cardiac death. This arrhythmia might be related to the persistence of parasitemia or inflammation in the myocardium in late-stage CHD. Positron emission tomography/computed tomography (PET/CT) has been used to detect myocardial inflammation in non-ischemic cardiomyopathies, such as sarcoidosis, and might be useful for risk prediction in patients with CHD.

METHODS AND RESULTS

Twenty-four outpatients with chronic CHD were enrolled in this prospective cross-sectional study between May 2019 and March 2022. The patients were divided into two groups: those with sustained ventricular tachycardia and/or aborted sudden cardiac death who required implantable cardioverter-defibrillators, and those with the same stages of CHD and no complex ventricular arrhythmia. Patients underwent 18F-fluorodeoxyglucose (18F-FDG) and 68Ga-DOTATOC PET/CT, and blood samples were collected for qualitative parasite assessment by polymerase chain reaction. Although similar proportions of patients with and without complex ventricular arrhythmia showed 18F-FDG and 68Ga-DOTATOC uptake, 68Ga-DOTATOC corrected SUVmax was higher in patients with complex arrhythmia (3.4 vs 1.7; P = .046), suggesting that inflammation could be associated with the presence of malignant arrhythmia in the late stages of CHD. We also detected Trypanosoma cruzi in both groups, with a nonsignificant trend of increased parasitemia in the group with malignant arrhythmia (66.7% vs 33.3%).

CONCLUSION

18F-FDG and 68Ga-DOTATOC uptake on PET/CT may be useful for the detection of myocardial inflammation in patients with Chagas cardiomyopathy, and 68Ga-DOTATOC uptake may be associated with the presence of malignant arrhythmia, with potential therapeutic implications.

Acute Chagas Disease Presenting as Preseptal Cellulitis

Chagas disease, also known as American trypanosomiasis, is caused by Trypanosoma cruzi, a parasite transmitted by hematophagous triatomine insects (subfamily Triatominae) belonging to the Reduviidae family, order Hemiptera. Infection occurs through contact with the feces of the infected vector at the site of its bite or on intact mucosa. [Pediatr Ann. 2023;52(10):e394-e397.].

Myocarditis: Etiology, Pathogenesis, and Their Implications in Clinical Practice

Myocarditis is an inflammatory disease of the myocardium caused by infectious or non-infectious agents. It can lead to serious short-term and long-term sequalae, such as sudden cardiac death or dilated cardiomyopathy. Due to its heterogenous clinical presentation and disease course, challenging diagnosis and limited evidence for prognostic stratification, myocarditis poses a great challenge to clinicians. As it stands, the pathogenesis and etiology of myocarditis is only partially understood. Moreover, the impact of certain clinical features on risk assessment, patient outcomes and treatment options is not entirely clear. Such data, however, are essential in order to personalize patient care and implement novel therapeutic strategies. In this review, we discuss the possible etiologies of myocarditis, outline the key processes governing its pathogenesis and summarize best available evidence regarding patient outcomes and state-of-the-art therapeutic approaches.

WHF Recommendations for the Use of Echocardiography in Chagas Disease

Chagas disease (ChD) represents a significant health burden in endemic regions of Latin America and is increasingly being recognized as a global health issue. The cardiac involvement in ChD, known as Chagas cardiomyopathy (ChCM), is the most severe manifestation and a leading cause of heart failure and mortality in affected individuals. Echocardiography, a non-invasive imaging modality, plays a crucial role in the diagnosis, monitoring, and risk stratification of ChCM. This consensus recommendation aims to provide guidance on the appropriate use of echocardiography in ChD. An international panel of experts, including cardiologists, infectious disease specialists, and echocardiography specialists, convened to review the available evidence and provide practical recommendations based on their collective expertise. The consensus addresses key aspects related to echocardiography in ChD, including its role in the initial evaluation, serial monitoring, and risk assessment of patients. It emphasizes the importance of standardized echocardiographic protocols, including the assessment of left ventricular function, chamber dimensions, wall motion abnormalities, valvular involvement, and the presence of ventricular aneurysm. Additionally, the consensus discusses the utility of advanced echocardiographic techniques, such as strain imaging and 3D echocardiography, in assessing myocardial mechanics and ventricular remodeling.

Cardiac Magnetic Resonance Imaging Detects Myocardial Abnormalities in Naturally Infected Dogs with Chronic Asymptomatic Chagas Disease

Trypanosoma cruzi infection causes inflammation and fibrosis, resulting in cardiac damage in dogs. The objectives of this study were to describe cardiac magnetic resonance imaging (CMR) in naturally infected dogs with chronic Chagas disease and the frequency of abnormalities for CMR and cardiac diagnostic tests. Ten asymptomatic, client-owned dogs seropositive for T. cruzi were prospectively enrolled in an observational study evaluating echocardiography, ECG (standard and ambulatory), cardiac troponin I (cTnI), and CMR. Standard ECG measurements (3/10) and cTnI concentration (1/10) outside the reference range were uncommon. Ambulatory ECG abnormalities were documented more frequently (6/10 dogs) than with standard ECG and included ventricular arrhythmias (4), supraventricular premature beats (3), second-degree atrioventricular block (2), and sinus arrest (1). Echocardiographic abnormalities were documented in 6/10 dogs including mildly increased left ventricular internal dimension in diastole (1) and decreased right ventricular (RV) systolic function based on reductions in tricuspid annular plane systolic excursion (3) and RV S' (4). Abnormalities were detected with CMR in 7/10 dogs including delayed myocardial enhancement in 5 of which 2 also had increased extracellular volume, abnormal wall motion in 5, and loss of apical compact myocardium in 1. In conclusion, CMR abnormalities were common, and the results of this study suggest CMR can provide useful information in dogs with T. cruzi infection and may support naturally infected dogs for future clinical investigation as an animal model for Chagas disease.

Chagas Disease

Chagas disease, which is caused by infection with the parasite Trypanosoma cruzi, is a leading neglected tropical disease in the United States. An estimated 240 000 to 350 000 persons in the United States are infected, primarily immigrants from Mexico, Central America, and South America, where the disease is endemic. The parasite is transmitted by the triatomine bug but can also be passed through blood transfusion, via organ transplant, or congenitally. Approximately 30% of infected persons later develop cardiac and/or gastrointestinal complications. Health care providers should consider screening at-risk patients with serologic testing. Early diagnosis and treatment with benznidazole or nifurtimox can help prevent complications.

Case report: diagnosis of chronic Chagas cardiomyopathy using a multimodality imaging approach

Background

In the USA, ∼300 000 people are affected by Chagas heart disease, a growing, but commonly overlooked, public health issue. Chagas as a potential aetiology of dilated cardiomyopathy remains under-recognized. We present a case where multimodality imaging was essential in the diagnosis and management of Chagas heart disease.

Case summary

A 54-year-old man, originally from Mexico, presented to the emergency department with chest pain and recurrent syncopal episodes, found to be in haemodynamically unstable ventricular tachycardia (VT) requiring urgent cardioversion. Urgent coronary angiography revealed no obstructive disease. A transthoracic echocardiogram revealed moderately reduced left ventricular systolic function (left ventricular ejection fraction 35-40%) with apical akinesis and an aneurysm of the apical septum. Cardiac magnetic resonance (CMR) confirmed a prominent apical aneurysm with dyskinesis of the apical septum, with the evidence of transmural myocardial late gadolinium enhancement of the entire left ventricular apex and a small apical thrombus. Serologic testing was positive for Trypanosoma cruzi IgG antibody, which was confirmed on repeat testing at the Centers for Disease Control and Prevention. Patient underwent VT ablation and was discharged on guideline-directed medical therapy including a regimen of anticoagulation, beta-blocker, and angiotensin-converting enzyme inhibitor therapies. He has had no subsequent syncope or VT.

Discussion

Chagas heart disease remains under-recognized and under-diagnosed despite the growing burden of T. cruzi infection in the USA. Suspicion for Chagas heart disease should be considered in patients presenting with heart failure symptoms and ventricular arrhythmias with the right corresponding history and imaging findings on echocardiogram and CMR.

Long-term cardiology outcomes in children after early treatment for Chagas disease, an observational study

BACKGROUND

Parasite persistence after acute infection with Trypanosoma cruzi is an important factor in the development of Chagas disease (CD) cardiomyopathy. Few studies have investigated the clinical effectiveness of CD treatment through the evaluation of cardiological events by long term follow-up of treated children. Cardiological evaluation in children is challenging since features that would be diagnosed as abnormal in an adult's ECG may be normal, age-related findings in a pediatric ECG trace. The objective was to evaluate cardiac involvement in patients with Chagas disease with a minimum follow-up of 6 years post-treatment.

METHODOLOGY

A descriptive study of a cohort of pediatric patients with CD treated with benznidazole (Bz) or nifurtimox (Nf) was conducted. Children (N = 234) with at least 6 years post CD treatment followed at the Parasitology and Chagas Service, Buenos Aires Children's Hospital (Argentina) were enrolled. By convenience sampling, children who attended a clinical visit between August 2015 and November 2019 were also invited to participate for additional cardiovascular studies like 24-hour Holter monitoring and speckle-tracking 2D echocardiogram (STE). Benznidazole was prescribed in 171 patients and nifurtimox in 63 patients. Baseline parasitemia data was available for 168/234 patients. During the follow-up period, alterations in routine ECG were observed in 11/234 (4.7%, 95% CI [2-7.4%]) patients. In only four patients, with complete right bundle branch block (cRBBB) and left anterior fascicular block (LAFB), ECG alterations were considered probably related to CD. During follow-up, 129/130 (99%) treated patients achieved persistent negative parasitemia by qPCR. Also decrease in T.cruzi antibodies titers was observed in all patients and negative seroconversion occurred in 123/234 (52%) patients.

CONCLUSIONS

A low incidence of cardiological lesions related to CD was observed in patients treated early for pediatric CD. This suggests a protective effect of parasiticidal treatment on the development of cardiological lesions and highlights the importance of early treatment of infected children.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04090489.

Chagas Heart Disease: Beyond a Single Complication, from Asymptomatic Disease to Heart Failure

Chagas cardiomyopathy (CC), caused by the protozoan Trypanosoma cruzi, is an important cause of cardiovascular morbidity and mortality in developing countries. It is estimated that 6 to 7 million people worldwide are infected, and it is predicted that it will be responsible for 200,000 deaths by 2025. The World Health Organization (WHO) considers Chagas disease (CD) as a Neglected Tropical Disease (NTD), which must be acknowledged and detected in time, as it remains a clinical and diagnostic challenge in both endemic and non-endemic regions and at different levels of care. The literature on CC was analyzed by searching different databases (Medline, Cochrane Central, EMBASE, PubMed, Google Scholar, EBSCO) from 1968 until October 2022. Multicenter and bioinformatics trials, systematic and bibliographic reviews, international guidelines, and clinical cases were included. The reference lists of the included papers were checked. No linguistic restrictions or study designs were applied. This review is intended to address the current incidence and prevalence of CD and to identify the main pathogenic mechanisms, clinical presentation, and diagnosis of CC.

Association of left ventricular abnormalities with incident cerebrovascular events and sources of thromboembolism in patients with chronic Chagas cardiomyopathy

BACKGROUND

Although Chagas cardiomyopathy is related to thromboembolic stroke, data on risk factors for cerebrovascular events in Chagas disease is limited. Thus, we assessed the relationship between left ventricular (LV) impairment and cerebrovascular events and sources of thromboembolism in patients with Chagas cardiomyopathy.

METHODS

This retrospective cohort included patients with chronic Chagas cardiomyopathy who underwent cardiovascular magnetic resonance (CMR). CMR was performed with a 1.5 T scanner to provide LV volumes, mass, ejection fraction (LVEF), and myocardial fibrosis. The primary outcome was a composite of incident ischemic cerebrovascular events (stroke or transient ischemic attack-TIA) and potential thromboembolic sources (atrial fibrillation (AF), atrial flutter, or intracavitary thrombus) during the follow-up.

RESULTS

A total of 113 patients were included. Median age was 56 years (IQR: 45-67), and 58 (51%) were women. The median LVEF was 53% (IQR: 41-62). LV aneurysms and LV fibrosis were present in 38 (34%) and 76 (67%) individuals, respectively. The median follow-up time was 6.9 years, with 29 events: 11 cerebrovascular events, 16 had AF or atrial flutter, and two had LV apical thrombosis. In the multivariable model, only lower LVEF remained significantly associated with the outcomes (HR: 0.96, 95% CI: 0.93-0.99). Patients with reduced LVEF lower than 40% had a much higher risk of cerebrovascular events and thromboembolic sources (HR: 3.16 95% CI: 1.38-7.25) than those with normal LVEF. The combined incidence rate of the combined events in chronic Chagas cardiomyopathy patients with reduced LVEF was 13.9 new cases per 100 persons-year.

CONCLUSIONS

LV systolic dysfunction is an independent predictor of adverse cerebrovascular events and potential sources of thromboembolism in patients with chronic Chagas cardiomyopathy.

Three and two-dimensional cardiac mechanics by speckle tracking are predictors of outcomes in chagas heart disease

Chagas disease (CD) is a neglected infectious disease associated with early mortality and substantial disability. Three-dimensional speckle tracking (3D STE) may play a role in the evaluation of CD. We aim to characterize new echocardiographic variables in patients with CD and to assess the hypothesis that 3D STE may predict outcomes. Seventy-two patients with CD were included. Clinical and conventional 2D and 3D STE analysis were performed. Patients were followed up for 60 months. Clinical events were defined as hospitalization for heart failure, complex ventricular arrhythmias, heart transplant and all-cause death. Seventy-two patients were recruited and enrolled in three groups: left ventricular ejection fraction (LVEF) < 0.40 (N = 22; reduced LVEF or rLVEF); 0.40 ≤ LVEF ≤ 0.50 (N = 10; mildly reduced LVEF or mrLVEF) and LVEF > 0.50 (N = 30; preserved LVEF or pLVEF). After a Cox model analysis, the top predictors of composite endpoints were 2D LV global longitudinal strain (GLS) ≤ − 11.3% (AUC = 0.87), 2D LV global circumferential strain (GCS) ≤  − 10.1% (AUC = 0.79), 3D LV GLS ≤ − 13% (AUC = 0.82), 3D LV area strain ≤ − 16% (AUC = 0.81) and right ventricle (RV) GLS ≤ − 17.2% (AUC = 0.78). Patients with CD and mrLVEF were morphologically similar to the rLVEF patients despite the benign evolution as the pLVEF group. RV GLS, 2D LV GLS, 2D LV GCS, 3D LV GLS, and 3D LV area strain are strong predictors of 60 months outcomes in patients with CD.

Prognosis of chronic Chagas heart disease and other pending clinical challenges

In this chapter, the main prognostic markers of Chagas heart disease are addressed, with an emphasis on the most recent findings and questions, establishing the basis for a broad discussion of recommendations and new approaches to managing Chagas cardiopathy. The main biological and genetic markers and the contribution of the electrocardiogram, echocardiogram and cardiac magnetic resonance are presented. We also discuss the most recent therapeutic proposals for heart failure, thromboembolism and arrhythmias, as well as current experience in heart transplantation in patients suffering from severe Chagas cardiomyopathy. The clinical and epidemiological challenges introduced by acute Chagas disease due to oral contamination are discussed. In addition, we highlight the importance of ageing and comorbidities in influencing the outcome of chronic Chagas heart disease. Finally, we discuss the importance of public policies, the vital role of funding agencies, universities, the scientific community and health professionals, and the application of new technologies in finding solutions for better management of Chagas heart disease.

Longitudinal strain by speckle tracking and echocardiographic parameters as predictors of adverse cardiovascular outcomes in chronic Chagas cardiomyopathy

To analyze the prognostic value of left ventricular global longitudinal strain (LV-GLS) and other echocardiographic parameters to predict adverse outcomes in chronic Chagas cardiomyopathy (CCM). Prospective cohort study conducted in 177 consecutive patients with different CCM stages. Transthoracic echocardiography measurements were obtained following the American Society of Echocardiography recommendations. By speckle-tracking echocardiography, LV-GLS was obtained from the apical three-chamber, apical two-chamber, and apical four-chamber views. The primary composite outcome (CO) was all-cause mortality, cardiac transplantation, and a left ventricular assist device implantation. After a median follow-up of 42.3 months (Q1 = 38.6; Q3 = 52.1), the CO incidence was 22.6% (95% CI 16.7-29.5%, n = 40). The median LV-GLS value was - 13.6% (Q1 =  - 18.6%; Q3 =  - 8.5%). LVEF, LV-GLS, and E/e' ratio with cut-off points of 40%, - 9, and 8.1, respectively, were the best independent CO predictors. We combined these three echocardiographic markers and evaluated the risk of CO according to the number of altered parameters, finding a significant increase in the risk across the groups. While in the group of patients in which all these three parameters were normal, only 3.2% had the CO; those with all three abnormal parameters had an incidence of 60%. We observed a potential incremental prognostic value of LV-GLS in the multivariate model of LVEF and E/e' ratio, as the AUC increased slightly from 0.76 to 0.79, nevertheless, this difference was not statistically significant (p = 0.066). LV-GLS is an important predictor of adverse cardiovascular events in CCM, providing a potential incremental prognostic value to LVEF and E/e' ratio when analyzed using optimal cut-off points, highlighting the potential utility of multimodal echocardiographic tools for predicting adverse outcomes in CCM.

Machine Learning-Based Feature Selection and Classification for the Experimental Diagnosis of Trypanosoma cruzi

Chagas disease, caused by the Trypanosoma cruzi (T. cruzi) parasite, is the third most common parasitosis worldwide. Most of the infected subjects can remain asymptomatic without an opportune and early detection or an objective diagnostic is not conducted. Frequently, the disease manifests itself after a long time, accompanied by severe heart disease or by sudden death. Thus, the diagnosis is a complex and challenging process where several factors must be considered. In this paper, a novel pipeline is presented integrating temporal data from four modalities (electrocardiography signals, echocardiography images, Doppler spectrum, and ELISA antibody titers), multiple features selection analyses by a univariate analysis and a machine learning-based selection. The method includes an automatic dichotomous classification of animal status (control vs. infected) based on Random Forest, Extremely Randomized Trees, Decision Trees, and Support Vector Machine. The most relevant multimodal attributes found were ELISA (IgGT, IgG1, IgG2a), electrocardiography (SR mean, QT and ST intervals), ascending aorta Doppler signals, and echocardiography (left ventricle diameter during diastole). Concerning automatic classification from selected features, the best accuracy of control vs. acute infection groups was 93.3 ± 13.3% for cross-validation and 100% in the final test; for control vs. chronic infection groups, it was 100% and 100%, respectively. We conclude that the proposed machine learning-based approach can be of help to obtain a robust and objective diagnosis in early T. cruzi infection stages.

Longitudinal Speckle Tracking Strain Abnormalities in Chagas Disease: A Systematic Review and Meta-Analysis

Background: Chronic Chagas cardiomyopathy (CCM) is ranked among heart failure etiologies with the highest mortality rates. CCM is characterized by alterations in left ventricular function with a typical and unique pattern of myocardial involvement. Left ventricle longitudinal speckle tracking strain is emerging as an important additive method for evaluating left ventricular function and risk of future cardiovascular events. This systematic review aimed to characterize the left ventricle (LV) longitudinal strain by speckle tracking patterns in the different stages of Chagas disease, compared to healthy controls. Methods: Searches in Medline, EMBASE, and LILACS databases (from inception to 20 May 2021) were performed. Articles written in any language that assessed patients with Chagas disease and reported any measures derived from the left ventricular strain by speckle tracking were included. Two reviewers independently selected the studies, extracted the data, and assessed the quality of evidence. Standardized mean differences (SMD) were pooled using random-effects meta-analyses. Results: Of 1044 references, ten studies, including a total of 1222 participants (CCM: 477; indeterminate form: 444; healthy controls: 301), fulfilled the selection criteria and were included in the final analysis. Patients with CCM had a significantly higher mean global longitudinal strain (GLS) value than indeterminate form (IF) patients (SMD 1.253; 95% CI 0.53, 1.98. I² = 94%), while no significant difference was observed between IF patients and healthy controls (SMD 0.197; 95% CI −0.19, 0.59. I² = 80%). Segmental strain analyses revealed that patients with the IF form of CD had significantly worse strain values in the basal-inferoseptal (SMD 0.49; 95% CI 0.24, 0.74. I²: 24%), and mid-inferoseptal (SMD 0.28; 95% CI 0.05, 0.50. I²: 10%) segments compared to healthy controls. Conclusions: Our results suggest different levels of functional derangements in myocardial function across different stages of Chagas disease. Further research is needed to assess the prognostic role of LV longitudinal strain and other measures derived from speckle tracking in CD patients regarding progression to cardiomyopathy and clinical outcomes prediction.

Left ventricular systolic dysfunction predicted by artificial intelligence using the electrocardiogram in Chagas disease patients-The SaMi-Trop cohort

Background

Left ventricular systolic dysfunction (LVSD) in Chagas disease (ChD) is relatively common and its treatment using low-cost drugs can improve symptoms and reduce mortality. Recently, an artificial intelligence (AI)-enabled ECG algorithm showed excellent accuracy to detect LVSD in a general population, but its accuracy in ChD has not been tested.

Objective

To analyze the ability of AI to recognize LVSD in patients with ChD, defined as a left ventricular ejection fraction determined by the Echocardiogram ≤ 40%.

Methodology/principal findings

This is a cross-sectional study of ECG obtained from a large cohort of patients with ChD named São Paulo-Minas Gerais Tropical Medicine Research Center (SaMi-Trop) Study. The digital ECGs of the participants were submitted to the analysis of the trained machine to detect LVSD. The diagnostic performance of the AI-enabled ECG to detect LVSD was tested using an echocardiogram as the gold standard to detect LVSD, defined as an ejection fraction <40%. The model was enriched with NT-proBNP plasma levels, male sex, and QRS ≥ 120ms.

Among the 1,304 participants of this study, 67% were women, median age of 60; there were 93 (7.1%) individuals with LVSD. Most patients had major ECG abnormalities (59.5%). The AI algorithm identified LVSD among ChD patients with an odds ratio of 63.3 (95% CI 32.3–128.9), a sensitivity of 73%, a specificity of 83%, an overall accuracy of 83%, and a negative predictive value of 97%; the AUC was 0.839. The model adjusted for the male sex and QRS ≥ 120ms improved the AUC to 0.859. The model adjusted for the male sex and elevated NT-proBNP had a higher accuracy of 0.89 and an AUC of 0.874.

Conclusion

The AI analysis of the ECG of Chagas disease patients can be transformed into a powerful tool for the recognition of LVSD.

Chagas disease (ChD) is caused by the protozoan parasite Trypanosoma cruzi and continues to be a health problem despite the control of its transmission. ChD is a heterogeneous condition with a wide variation in its clinical course and prognosis. The majority (60%–70%) of infected individuals remain asymptomatic throughout life. Although some develop only conduction defects and mild segmental wall motion abnormalities, others develop severe symptoms of heart failure (HF), thromboembolic phenomena, and life threatening ventricular arrhythmias. HF is one of major causes of the death of patients with ChD. There is some evidence on effective drugs against the parasite in the chronic form of the disease capable of preventing long-term adverse outcomes, but it is still limited. However low-cost medications are able to reduce mortality and improve the quality of life of patients with HF. Because of the lack of tertiary care facilities outside urban centers, an automatic diagnostic tool based on the ECG, which is a relatively simple exam without requiring human interpretation, would improve the capacity to recognize HF. Recently, digital signals of the electrocardiogram were recognized by Artificial Intelligence (AI) and associated with an excellent accuracy for HF in the general population. Our results demonstrate that AI-ECG could ensure a rapid recognition of HF in patients who require a referral to a cardiologist and the use of disease-modifying drugs. AI can be used as a powerful public heath tool, it can transform the lives of 6 million patients with ChD worldwide, and it may well have a formidable impact on patient management and prognosis.

Circulating DHEA-S levels and major cardiovascular outcomes in chronic Chagas cardiomyopathy: A prospective cohort study

OBJECTIVE

To analyze the association of circulating dehydroepiandrosterone sulfate (DHEA-S) levels with cardiovascular outcomes in patients with chronic Chagas cardiomyopathy (CCM) diagnosis.

BACKGROUND

DHEA-S is among the main endogenous steroid hormones. Some studies have suggested a relevant role of this hormone in infections and the setting of CCM. Nevertheless, no study has evaluated the prognostic role of DHEA-S in CCM patients.

METHODS

Prospective cohort study. Patients with CCM and reduced ejection fraction were included. We explored the association of DHEA-S levels with NT-proBNP levels and echocardiographic variables using linear regression models. Next, by using Cox Proportional Hazard models, we examined whether levels of DHEA-S could predict a composite outcome (CO) including all-cause mortality, cardiac transplantation, and implantation of a left ventricular assist device (LVAD).

RESULTS

Seventy-four patients were included (59% males, median age: 64 years). After adjustment for confounding factors, high DHEA-S levels were associated with better LVEF, lower left atrium volume, end-systolic volume of the left ventricle and lower NT-proBNP levels. 43% of patients experienced the CO during a median follow-up of 40 months. Increased levels of DHEA-S were associated with a lower risk of developing the CO (HR 0.43; 95%CI 0.21-0.86). Finally, adding DHEA-S to the multivariate model did not improve the prediction of the CO, but substituting NT-proBNP in the model with DHEA-S showed similar performance.

CONCLUSIONS

In patients with CCM, higher DHEA-S levels were associated with lower mortality, heart transplantation, and LVAD implantation. Further larger studies are required to confirm our results and assess causality.

Accuracy and reliability of focused echocardiography in patients with Chagas disease from endemic areas: SaMi-Trop cohort study

BACKGROUND

Chagas disease remains a major cause of cardiovascular death in endemic areas. Focused echocardiography (FoCUS) is a point-of-care means of assessing cardiac function which can be useful for the diagnosis of cardiac involvement.

OBJECTIVE

This study aims evaluating the characteristics of validity and reliability of FoCUS applied on Chagas disease patients.

METHODS

Patients with Chagas disease coming from an endemic area were selected from a large cohort (SaMi-Trop). A simplified echocardiogram with only three images was extracted from the conventional echocardiogram performed in this cohort. The images were evaluated by an observer who was blinded to the clinical and echocardiographic data, to determine the accuracy and reliability of FoCUS for cardiac assessment. The analysis constituted of 5 prespecified variables, dichotomized in absence or presence: left ventricular (LV) size and systolic function, right ventricular (RV) size and systolic function, and LV aneurysm.

RESULTS

We included 725 patients with a mean age of 63.4 ± 12.3 years, 483 (67%) female. Abnormal electrocardiogram was observed in 81.5% of the patients. Left and right ventricular dysfunctions were found in 103 (14%) and 49 (7%) of the patients, respectively. Sensitivity, specificity, positive predictive value and negative predictive value were 84%, 94%, 70% and 97% for LV enlargement and 81%, 93%, 68% and 97% for LV systolic dysfunction, respectively, and 46%, 99%, 60% and 98% for RV dilatation, and 37%, 100%, 100% and 96% for RV dysfunction, respectively. Inter and intraobserver agreement were 61% and 87% for LV enlargement and 63% and 92% for LV dysfunction, respectively, and 50% and 49% for RV size and 46% and 79% for RV dysfunction, respectively. LV apical aneurysm was found in 45 patients (6.2%) with the lowest sensitivity of FoCUS study (11%; 95% CI 2-28%).

CONCLUSIONS

FoCUS showed satisfactory values of validity and reliability for assessment of cardiac chambers in patients with Chagas disease, except for apical aneurysm. This tool can identify heart disease with potential impact on patient management in the limited-resource setting.

Cardiovascular biomarkers as predictors of adverse outcomes in chronic Chagas cardiomyopathy

BACKGROUND

Chronic Chagas Cardiomyopathy (CCM) is a unique form of cardiomyopathy compared to other etiologies of heart failure. In CCM, risk prediction based on biomarkers has not been well-studied. We assessed the prognostic value of a biomarker panel to predict a composite outcome (CO), including the need for heart transplantation, use of left ventricular assist devices, and mortality.

METHODS

Prospective cohort study of 100 adults with different stages of CCM. Serum concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP), galectin-3 (Gal-3), neutrophil gelatinase-associated lipocalin (NGAL), high sensitivity troponin T (hs-cTnT), soluble (sST2), and cystatin-C (Cys-c) were measured. Survival analyses were performed using Cox proportional hazard models.

RESULTS

During a median follow-up of 52 months, the mortality rate was 20%, while the CO was observed in 25% of the patients. Four biomarkers (NT-proBNP, hs-cTnT, sST2, and Cys-C) were associated with the CO; concentrations of NT-proBNP and hs-cTnT were associated with the highest AUC (85.1 and 85.8, respectively). Combining these two biomarkers above their selected cut-off values significantly increased risk for the CO (HR 3.18; 95%CI 1.31-7.79). No events were reported in the patients in whom the two biomarkers were under the cut-off values, and when both levels were above cut-off values, the CO was observed in 60.71%.

CONCLUSION

The combination of NT-proBNP and hs-TnT above their selected cut-off values is associated with a 3-fold increase in the risk of the composite outcome among CCM patients. The use of cardiac biomarkers may improve prognostic evaluation of patients with CCM.

Left ventricular longitudinal strain and strain rate measurements in paediatric patients in long-term treatment for Chagas disease

INTRODUCTION

Previous echocardiographic studies failed to show residual alterations of heart function in paediatric patients that have received treatment for Chagas disease. While the echocardiogram is the fundamental front-line tool for evaluating heart function, the appearance of new techniques allows a more detailed analysis. We aimed to evaluate systolic and diastolic function with new techniques in a paediatric population with Chagas disease several years after treatment completion.

MATERIAL AND METHODS

Echocardiograms were obtained from 84 Chagas disease patients (48 female) and 27 healthy controls. All patients had received treatment concluding on average 10 years prior to the study. The prospective analysis considered cardiac dimensions and cardiac function using two-dimensional, M-mode, Doppler and tissue Doppler imaging with emphasis on measuring longitudinal strain in the left ventricle by speckle tracking. Ejection fraction was measured with three-dimensional echocardiography.

RESULTS

Patients had an age of 14.2 ± 5.7 years (6-33) at the time of evaluation. Global and segmental motility of the left ventricle was normal in all patients. Ejection fraction was 59.2 ± 6.5 and 57.4 ± 6.5% (p = 0.31) in patients and controls respectively. Left ventricular global longitudinal systolic strain was -19 ± 2.4% in patients and -19 ± 3.6% (p = 0.91) in controls. No significant differences were found in remaining systolic and diastolic function measurements.

CONCLUSIONS

Paediatric patients that have received treatment for Chagas disease, evaluated with either conventional techniques or new tools, do not show significant long-term alterations of ventricular function.

ACR Appropriateness Criteria® Nonischemic Myocardial Disease with Clinical Manifestations (Ischemic Cardiomyopathy Already Excluded)

Nonischemic cardiomyopathies encompass a broad spectrum of myocardial disorders with mechanical or electrical dysfunction without evidence of ischemia. There are five broad variants of nonischemic cardiomyopathies; hypertrophic cardiomyopathy (Variant 1), restrictive or infiltrative cardiomyopathy (Variant 2), dilated or unclassified cardiomyopathy (Variant 3), arrhythmogenic cardiomyopathy (Variant 4), and inflammatory cardiomyopathy (Variant 5). For variants 1, 3, and 4, resting transthoracic echocardiography, MRI heart function and morphology without and with contrast, and MRI heart function and morphology without contrast are the usually appropriate imaging modalities. For variants 2 and 5, resting transthoracic echocardiography and MRI heart function and morphology without and with contrast are the usually appropriate imaging modalities. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Comparison of the Outcomes between Coronary No-Reflow and Slow-Flow Phenomenon in Non-STEMI Patients

BACKGROUND

Coronary slow-flow phenomenon (CSFP) and coronary no-reflow phenomenon (CNP) are associated with increased risk of major cardiovascular adverse events (MACE).

OBJECTIVES

This study aimed to evaluate and compare the one-year clinical follow-up outcomes among patients with CNP and CSFP who underwent percutaneous coronary interventions (PCI) in non-ST elevation myocardial infarction (NSTEMI).

METHODS

This study included a total of 858 patients who were diagnosed with NSTEMI and underwent PCI within 24 h of symptom onset. The patients were divided into two groups, the CSFP group (n=221) and the CNP group (n=25), regarding the angiographic characteristics of thrombolysis in myocardial infarction (TIMI) flow of the infarct-related artery. Patients were followed for one-year. A p-value of <0.05 was considered significant.

RESULTS

CNP was observed in 2.91%, and CSFP was observed in 25.75% of the patients. Clinical endpoints analyzed that stroke was significantly higher in the CNP group than in the CSFP group (6 (24%) vs. 6 (2.70%), p<0.001) and MACE was significantly higher in the CNP group than in the CSFP group (11 (44%) vs. 51 (23.10%), p=0.022). Forward conditional logistic regression analysis demonstrated that body mass index (BMI) (OR=1.11, 95%CI: 1.00-1.24, p=0.038) and baseline heart rate (HR) (OR=0.923, 95%CI: 0.88-0.96, p<0.001) were the independent predictors of CNP in NSTEMI.

CONCLUSION

CNP patients have worse clinical outcomes and a higher risk of stroke compared with CSFP patients in NSTEMI. (Arq Bras Cardiol. 2021; 116(5):856-864).

Clinical Presentations of Chagas Cardiomyopathy

Chronic Chagas cardiomyopathy (CCC) is the most common cause of nonischemic cardiomyopathy in endemic Latin American countries. Immigrants to the United States suffer from this disease, but it is underrecognized. We describe the three hallmark clinical presentations: stroke, ventricular arrhythmias, and heart failure, which should prompt suspicion for CCC.

Speckle tracking echocardiography in the indeterminate form of Chagas disease

BACKGROUND

Chagas disease is one of the most common diseases in Latin-America, and cardiac involvement is a significant cause of death. Assessment of myocardial strain may detect early myocardial damage.

OBJECTIVES

To determine differences in longitudinal strain using speckle tracking to assess regional and global left ventricular function in patients with the indeterminate form of Chagas disease, in comparison with a control group.

METHODS

This is a retrospective matched case-control study, conducted in a single center. We evaluated 45 adult patients with Chagas disease, diagnosed with 2 serological methods, without evidence of cardiac involvement, who were compared with 45 healthy control subjects, who were sex- and age-matched. All patients underwent Doppler echocardiography and longitudinal strain with speckle tracking.

RESULTS

Median age was 59 years, and 60% were female. Echocardiographic parameters were similar in patients with Chagas and control subjects. In patients with Chagas, global strain differed significantly from that of control subjects (-17 vs -20.3, P < .001). Segmental strain showed 7 abnormal segments in patients with Chagas (P < .05).

CONCLUSIONS

In patients with the indeterminate form of Chagas disease, global and segmental longitudinal peak systolic strain is reduced compared with healthy subjects, thus suggesting that it could be a sensitive technique to detect early myocardial damage. These findings could provide useful information regarding the pathophysiology of cardiac involvement and understand whether they might have prognostic usefulness or help develop strategies to modify the course and prognosis of patients with Chagas disease. A longitudinal prospective study would be necessary to validate our findings.

Comparison of Noninvasive Cardiac Test Strategies for Newly Diagnosed Chagas Disease in a Non-Endemic Zone

Chagas disease is an emerging infectious disease in Europe and other non-endemic areas, mainly owing to migration from endemic areas. We aimed at investigating the value of advanced echocardiography (ECHO) and cardiac magnetic resonance (CMR) in patients newly diagnosed with Chagas disease to compare findings with those of electrocardiogram (ECG) and conventional ECHO and thus detecting cardiac abnormalities. We included consecutive patients with newly diagnosed Chagas disease and registered cardiac test results (ECG, ECHO, and CMR). We divided ECHO parameters into three tiers: 1) left ventricular ejection fraction, regional wall motion abnormality, and left ventricular diastolic dimension (ECHO-1); 2) other common ECHO parameters (ECHO-2); and 3) global longitudinal strain (GLS) (ECHO-3). Cardiac magnetic resonance included global and segmental biventricular function, the presence of myocardial fibrosis, and edema. The study comprised 100 patients from South America. The mean age was 43.9 ± 0.9 years, and 66% were women. Mean time living in Spain was 9.7 ± 0.5 years. The ECG revealed ≥ 2 abnormal findings in 47% of patients. ECHO-1 was abnormal in 22% of patients, ECHO-2 in 52%, and GLS in 16%. Cardiac magnetic resonance was abnormal in 50% of cases, and in 3% of these, ECHO was normal. When ECG and conventional ECHO were taken together, abnormalities were detected in 83% of patients. This value increased to 86% and 92% for GLS and CMR, respectively. These findings suggest that ECG and conventional ECHO should be used routinely as standard cardiac tests for newly diagnosed cases of Chagas disease. The value of advanced ECHO techniques and CMR is low.

Left Atrial Structure and Function Predictors of New-Onset Atrial Fibrillation in Patients with Chagas Disease

BACKGROUND

Atrial fibrillation (AF) carries ominous consequences in patients with Chagas disease. The aim of this study was to determine whether left atrial (LA) volume and function assessed using three-dimensional echocardiographic (3DE) imaging and two-dimensional speckle-tracking echocardiographic deformation analysis of strain (ε) could predict new-onset AF in patients with Chagas disease.

METHODS

A total of 392 adult patients with chronic Chagas disease (59% women; mean age, 53 ± 11 years) who underwent echocardiography were consecutively enrolled in this prospective longitudinal study. Echocardiographic evaluation included two-dimensional (2D) Doppler echocardiography, with evaluation of left ventricular systolic and diastolic function, LA size, and LA and left ventricular function on 3DE and ε analyses. Multivariate Cox proportional-hazards regression analysis models adjusting for age, sex, hypertension, presence of a pacemaker, and 2D Doppler echocardiographic parameters were used to test if the variables of interest had independent prognostic value for AF prediction.

RESULTS

Patients with Chagas disease were followed for 5.6 ± 2.7 years. Among these, 139 (35.5%) had the indeterminate form, 224 (57.1%) had the cardiac form, five (1.3%) had the digestive form, and 24 (6.1%) had the cardiodigestive form. The study end point of AF occurred in 45 patients. Total LA emptying fraction (hazard ratio, 0.93; 95% CI, 0.89-0.98; P = .002), passive LA emptying fraction (HR, 0.95; 95% CI, 0.91-0.99; P = .02), and peak negative global LA ε (HR, 1.22; 95% CI, 1.05-1.41; P = .01) were predictors of new-onset AF independent of clinical and 2D Doppler echocardiographic parameters.

CONCLUSIONS

LA function assessed on 3DE and ε analyses predicts new-onset AF in patients with Chagas disease independent of clinical and 2D Doppler echocardiographic indexes.

Clinical significance of tissue Doppler imaging in chronic Chagas disease

INTRODUCTION

Chagas disease (ChD) is one of the main parasitic diseases in Latin-America. Its heart involvement is the most important cause of death. The aim of this study is to evaluate if Doppler Tissue Imaging (DTI) may have a predictive value for later events in subjects with chronic ChD.

METHODS

we analyses DTI variables of 543 patients with chronic ChD for the evaluation of predicting factors of events. Major adverse cardiovascular events (MACE) were considered as stroke, heart failure resistant to treatment, sustained ventricular tachycardia, implantable cardioverter-defibrillator, sudden death, and cardiovascular death. The following findings were also included in total evens: heart failure, bradycardia, ventricular arrhythmia, new conduction system abnormalities, and new echocardiographic abnormalities. Multivariate analysis with logistic regression was used in order to assess the Doppler and DTI parameters predicting events. Variables with a P-value ≤ .5 in the univariate analysis were included in the multivariate analysis.

RESULTS

In patients with chronic ChD, the analysis of DTI parameters showed that S' wave and E' wave of the lateral wall of the left ventricle were significant predictors of MACE (OR: 0.83; 95% CI: 0.71-0.96; P-value: .015 and OR: 0.80; 95% CI: 0.66-0.98; P-value: .031, respectively).

CONCLUSIONS

This study found that patients with chronic ChD who had events showed significantly lower parameters in the DTI. What is more, this study showed that even lower DTI parameters are significant predictors of events.

New Imaging Parameters to Predict Sudden Cardiac Death in Chagas Disease

Chronic Chagas' cardiomyopathy is the most severe and frequent manifestation of Chagas disease, and has a high social and economic burden. New imaging modalities, such as strain echocardiography, nuclear medicine, computed tomography and cardiac magnetic resonance imaging, may detect the presence of myocardial fibrosis, inflammation or sympathetic denervation, three conditions associated with risk of sudden death, providing additional diagnostic and/or prognostic information. Unfortunately, despite its high mortality, there is no clear recommendation for early cardioverter-defibrillator implantation in patients with Chagas heart disease in the current guidelines. Ideally, the risk of sudden cardiac death may be evaluated in earlier stages of the disease using new image methods to allow the implementation of primary preventive strategies.

Chagas heart disease: A contemporary review

Chagas disease is caused by a parasite infection endemic of the Americas. Traditionally observed in rural areas of Latin America, current migration trends have turned Chagas disease into a global epidemic. Acute infection is rarely severe and once it resolves, some patients can develop cardiomyopathy as part of the chronic form many years later. Multiple factors related with both the host and the parasite determine the susceptibility and progression to cardiomyopathy. Current imaging techniques are able to identify cardiac autonomic denervation, perfusion abnormalities, and myocardial fibrosis at an early of stage before the development of symptoms. The prognosis of patients with Chagasic cardiomyopathy remains poor and life-threatening ventricular arrhythmias can occur at an early stage. Treatment of chronic Chagas cardiomyopathy is challenging with a great need for more studies in the field.

WHF IASC Roadmap on Chagas Disease

Background

Chagas Disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, with some of the most serious manifestations affecting the cardiovascular system. It is a chronic, stigmatizing condition, closely associated with poverty and affecting close to 6 million people globally. Although historically the disease was limited to endemic areas of Latin America recent years have seen an increasing global spread. In addition to the morbidity and mortality associated with the disease, the social and economic burdens on individuals and society are substantial. Often called the 'silent killer', Chagas disease is characterized by a long, asymptomatic phase in affected individuals. Approximately 30% then go on develop chronic Chagas cardiomyopathy and other serious cardiac complications such as stroke, rhythm disturbances and severe heart failure.

Methods

In a collaboration of the World Hearth Federation (WHF) and the Inter-American Society of Cardiology (IASC) a writing group consisting of 20 diverse experts on Chagas disease (CD) was convened. The group provided up to date expert knowledge based on their area of expertise. An extensive review of the literature describing obstacles to diagnosis and treatment of CD along with proposed solutions was conducted. A survey was sent to all WHF Members and, using snowball sampling to widen the consultation, to a variety of health care professionals working in the CD global health community. The results were analyzed, open comments were reviewed and consolidated, and the findings were incorporated into this document, thus ensuring a consensus representation.

Results

The WHF IASC Roadmap on Chagas Disease offers a comprehensive summary of current knowledge on prevention, diagnosis and management of the disease. In providing an analysis of 'roadblocks' in access to comprehensive care for Chagas disease patients, the document serves as a framework from which strategies for implementation such as national plans can be formulated. Several dimensions are considered in the analysis: healthcare system capabilities, governance, financing, community awareness and advocacy.

Conclusion

The WHF IASC Roadmap proposes strategies and evidence-based solutions for healthcare professionals, health authorities and governments to help overcome the barriers to comprehensive care for Chagas disease patients. This roadmap describes an ideal patient care pathway, and explores the roadblocks along the way, offering potential solutions based on available research and examples in practice. It represents a call to action to decision-makers and health care professionals to step up efforts to eradicate Chagas disease.

Echocardiographic parameters, speckle tracking, and brain natriuretic peptide levels as indicators of progression of indeterminate stage to Chagas cardiomyopathy

BACKGROUND

Chronic Chagas cardiomyopathy (CCM) is characterized by a unique type of cardiac involvement. Few studies have characterized echocardiographic (Echo) transitions from the indeterminate Chagas disease (ChD) form to CCM. The objective of this study was to identify the best cutoffs in multiple Echo parameters, speckle tracking, and N-terminal pro B-type natriuretic peptide (NT-proBNP) to distinguish patients without CCM (stage A) vs patients with myocardial involvement (stages B, C, or D).

METHODS

Cross-sectional study conducted in 273 consecutive patients with different CCM stages. Echo parameters, NT-proBNP, and other clinical variables were measured. Logistic regression models (dichotomized in stage A versus B, C, and D) adjusted for age, sex, body mass index, and NT-proBNP were performed.

RESULTS

Left ventricular global longitudinal strain (LV-GLS), mitral flow E velocity, LV mass index, and NT-proBNP identified early changes that differentiated stages A vs B, C, and D. The LV-GLS with a cutoff -20.5% showed the highest performance (AUC 92.99%; accuracy 84.56% and negative predictive value (NPV) 88.82%), which improved when it was additionally adjusted by NT-proBNP with a cutoff -20.0% (AUC 94.30%; accuracy 88.42% and NPV 93.55%).

CONCLUSIONS

Our findings suggest that Echo parameters and NT-proBNP may be used as diagnostic variables in detecting the onset of myocardial alterations in patients with the indeterminate stage of ChD. LV-GLS was the more accurate measurement regarding stage A differentiation from the stages B, C, and D. Prospective longitudinal studies are needed to validate these findings.

Chagas Disease in the United States: a Public Health Approach

Trypanosoma cruzi is the etiological agent of Chagas disease, usually transmitted by triatomine vectors. An estimated 20 to 30% of infected individuals develop potentially lethal cardiac or gastrointestinal disease. Sylvatic transmission cycles exist in the southern United States, involving 11 triatomine vector species and infected mammals such as rodents, opossums, and dogs. Nevertheless, imported chronic T. cruzi infections in migrants from Latin America vastly outnumber locally acquired human cases. Benznidazole is now FDA approved, and clinical and public health efforts are under way by researchers and health departments in a number of states. Making progress will require efforts to improve awareness among providers and patients, data on diagnostic test performance and expanded availability of confirmatory testing, and evidence-based strategies to improve access to appropriate management of Chagas disease in the United States.

Chagas Disease: Chronic Chagas Cardiomyopathy

Chagas disease (CD) is a tropical vector-borne infection caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), also known as American Trypanosomiasis. It is considered endemic in all South and Central America and in this past decades its becoming a burden particularly in the United States and Europe due to human migration. The vast majority of patients during the acute phase are asymptomatic, while chronic symptomatic phase appears years later, with around 30% progressing toward detectable organ damage affecting mainly the cardiovascular and digestive systems. Chagas cardiomyopathy is the leading cause of nonischemic cardiomyopathy (NICM) in Latin America and affects around 30% of infected patients. The foremost characteristics are a diffuse myocarditis with focal fibrosis, mainly located in the apex and basal segments of the posterior and inferior wall, leading to a highly arrhythmogenic disease. Treatment can be etiologic during the parasitic infection, without and established efficacy during the advanced chronic symptomatic phase. Chronic Chagas cardiomyopathy treatment consists in guided medical therapy for non-ischemic cardiomyopathy, but more studies are imperative to improve clinical outcomes, some of them already in progress, and hopefully soon refine treatment and recommendations.

Incidence and variables associated with arrhythmias during dobutamine-atropine stress echocardiography among patients with Chagas disease

BACKGROUND

Dobutamine stress echocardiography (DSE) is an important tool in the diagnosis of coronary artery disease. However, there is hesitation in clinical practice for using it in patients with Chagas disease (CD) due to the arrhythmogenic potential of this heart condition. This study aimed to evaluate the incidence and variables associated with arrhythmias during DSE in a population of patients with CD.

METHODS

A population of 205 consecutive patients with CD and suspected coronary heart disease was assessed through a retrospective database analysis. CD was confirmed in all patients by serological testing.

RESULTS

The mean age of the patients selected was 64 years, and 65.4% of the patients were female. Significant arrhythmias occurred as follows: nonsustained ventricular tachycardia in 7.3% of patients; supraventricular tachycardia and sustained ventricular tachycardia in 1%; and atrial fibrillation in 0.5%. Nonsignificant arrhythmias occurred as follows: premature ventricular contractions in 48% of patients and bigeminy in 4.4%. Values for the wall-motion score index at rest greater than 1.12 and 1.18 were independently correlated with the occurrence of nonsignificant arrhythmias (odds ratio [OR] = 2.90, P < 0.001) and significant arrhythmias (OR = 4.23, P = 0.044), respectively.

CONCLUSION

DSE should be considered a safe examination in patients with CD despite the known increased risk of arrhythmias in this group of patients. The occurrence of arrhythmias was low in this study. Abnormal wall-motion score index values at rest were associated with the occurrence of significant and nonsignificant arrhythmias during the test.

Effects of Trypanocidal Treatment on Echocardiographic Parameters in Chagas Cardiomyopathy and Prognostic Value of Wall Motion Score Index: A BENEFIT Trial Echocardiographic Substudy

BACKGROUND

Serial echocardiographic studies in chronic Chagas cardiomyopathy are scarce. The aims of this study were to evaluate whether therapy with benznidazole modifies the progression of cardiac impairment and to identify baseline echocardiographic parameters related to prognosis.

METHODS

A prospective substudy was conducted in 1,508 patients with chronic Chagas cardiomyopathy randomized to benznidazole or placebo, who underwent two-dimensional echocardiography at enrollment, 2 years, and final follow-up (5.4 years). Left ventricular (LV) ejection fraction, LV wall motion score index (WMSI), indexed left atrial volume, and chamber dimensions were collected and correlated to all-cause death and a composite hard outcome using univariate and multivariate analyses.

RESULTS

At enrollment, most patients had normal chamber dimensions, and 70.5% had preserved LV ejection fractions. During follow-up, all chamber dimensions increased similarly in both treatment arms. LV ejection fraction was comparably reduced (55.7 ± 12.7% to 52.1 ± 14.6% vs 56.3 ± 12.7% to 52.8 ± 14.1%) and LV WMSI similarly increased (1.31 ± 0.41 to 1.49 ± 0.03 and 1.27 ± 0.38 to 1.51 ± 0.03) for the benznidazole and placebo groups, respectively (P > .05). A higher baseline LV WMSI was identified in subjects who died compared with those alive at final echocardiography (1.76 ± 0.517 vs 1.271 ± 0.393, P < .0001). There was a significant (P < .0001) graded increase in the risk for the composite outcome with worsening LV WMSI (hazard ratios, 2.27 [95% CI, 1.69-3.06] and 6.42 [95% CI, 4.94-8.33]) and also of death (hazard ratios, 2.45 [95% CI, 1.62-3.71] and 8.99 [95% CI, 6.3-12.82]) for 1 < LV WMSI < 1.5 and LV WMSI > 1.5, respectively. Both LV WMSI and indexed left atrial volume remained independent predictors in multivariate analysis.

CONCLUSIONS

Trypanocidal treatment had no effect on echocardiographic progression of chronic Chagas cardiomyopathy over 5.4 years. Despite normal global LV systolic function, regional wall motion abnormalities and indexed left atrial volume identified patients at higher risk for hard adverse clinical outcomes.

Scientometrics analysis of research activity and collaboration patterns in Chagas cardiomyopathy

Background

Chagas cardiomyopathy is a serious and common complication of Chagas disease.

Methods

Through bibliometric and Social Network Analysis, we examined patterns of research on Chagas cardiomyopathy, identifying the main countries, authors, research clusters, and topics addressed; and measuring the contribution of different countries.

Results

We found 1932 documents on Chagas cardiomyopathy in the MEDLINE database. The most common document type was ‘journal article’, accounting for 79.6% of the total (n = 1538), followed by ‘review’ (n = 217, 11.2%). The number of published records increased from 156 in 1980–1984 to 311 in 2010–2014. Only 2.5% were clinical trials. Brazil and the USA dominated the research, participating in 53.1% and 25.7%, respectively, of the documents. Other Latin American countries where Chagas is endemic contributed less, with Bolivia, where Chagas disease is most prevalent, producing only 1.8% of the papers. We observed a high rate of domestic collaboration (83.1% of the documents published in 2010–2016) and a lower but significant rate of international collaboration (32.5% in the same time period). Although clinical research dominated overall, the USA, Mexico and several countries in Europe produced a considerable body of basic research on animal models. We identified four main research clusters, focused on heart failure and dysfunction (physical symptoms, imaging techniques, treatment), and on myocarditis and parasitemia in animal models.

Conclusions

Research on Chagas cardiomyopathy increased over the study period. There were more clinical than basic studies, though very few of the documents were clinical trials. Brazil and the USA are currently leading the research on this subject, while some highly endemic countries, such as Bolivia, have contributed very little. Different approaches could help to redress this imbalance: encouraging researchers to conduct more clinical trials, launching international collaborations to help endemic countries contribute more, and strengthening links between basic and clinical research.

Scientific production on Chagas cardiomyopathy has grown considerably since the turn of the 21st century, probably reflecting the increased incidence of Chagas disease in non-endemic areas like the USA and Europe. Brazil and the USA dominate the research, but we found a very small proportion of clinical trials on Chagas cardiomyopathy and a low scientific production in several endemic countries with a high prevalence of the disease such as Colombia, Chile, Mexico and Bolivia. We observed a polarity between endemic and non-endemic countries where clinical research and basic research predominate, respectively. Different approaches could help to redress the observed imbalance of research on Chagas cardiomyopathy: encouraging researchers to conduct more clinical trials, launching international collaborations to help endemic countries contribute more, and strengthening links between basic and clinical research. It is crucial to foster translational research in order to link basic knowledge on the physiology of the disease with clinical applications in diagnosis and treatment.