Chagas cardiomyopathy: the potential of diastolic dysfunction and brain natriuretic peptide in the early identification of cardiac damage

Risk Factors for Progression to Chronic Chagas Cardiomyopathy: A Systematic Review and Meta-Analysis

Approximately one-third of people with chronic Trypanosoma cruzi infection develop Chagas cardiomyopathy, which carries a poor prognosis. Accurate prediction of which individuals will go on to develop Chagas cardiomyopathy remains elusive. We performed a systematic review of literature comparing characteristics of individuals with chronic Chagas disease with or without evidence of cardiomyopathy. Studies were not excluded on the basis of language or publication date. Our review yielded a total of 311 relevant publications. We further examined the subset of 170 studies with data regarding individual age, sex, or parasite load. A meta-analysis of 106 eligible studies indicated that male sex was associated with having Chagas cardiomyopathy (Hedge's g: 1.56, 95% CI: 1.07-2.04), and a meta-analysis of 91 eligible studies indicated that older age was associated with having Chagas cardiomyopathy (Hedge's g: 0.66, 95% CI: 0.41-0.91). A meta-analysis of four eligible studies did not find an association between parasite load and disease state. This study provides the first systematic review to assess whether age, sex, and parasite load are associated with Chagas cardiomyopathy. Our findings suggest that older and male patients with Chagas disease are more likely to have cardiomyopathy, although we are unable to identify causal relationships due to the high heterogeneity and predominantly retrospective study designs in the current literature. Prospective, multidecade studies are needed to better characterize the clinical course of Chagas disease and identify risk factors for progression to Chagas cardiomyopathy.

Cardiovascular Biomarkers and Diastolic Dysfunction in Patients With Chronic Chagas Cardiomyopathy

Background: Chronic Chagas Cardiomyopathy is a unique form of cardiomyopathy, with a significantly higher mortality risk than other heart failure etiologies. Diastolic dysfunction (DD) plays an important role in the prognosis of CCM; however, the value of serum biomarkers in identifying and stratifying DD has been poorly studied in this context. We aimed to analyze the correlation of six biochemical markers with diastolic function echocardiographic markers and DD diagnosis in patients with CCM.

Methods: Cross-sectional 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. Tissue Doppler imaging was used to measure echocardiographic parameters indicating DD. Multivariate logistic regression models adjusted by age, sex, BMI, and NYHA classification were used to evaluate the association between the biomarkers and DD.

Results: From the total patients included (55% male with a median age of 62 years), 38% had a preserved LVEF, but only 14% had a normal global longitudinal strain. Moreover, 64% had a diagnosis of diastolic dysfunction, with most of the patients showing a restrictive pattern (n = 28). The median levels of all biomarkers (except for sST2) were significantly higher in the group of patients with DD. Higher levels of natural log-transformed NTproBNP (per 1-unit increase, OR = 3.41, p < 0.001), Hs-cTnT (per 1-unit increase, OR = 3.24, p = 0.001), NGAL (per 1-unit increase, OR = 5.24, p =0.003), and Cys-C (per 1-unit increase, OR = 22.26, p = 0.008) were associated with increased odds of having diastolic dysfunction in the multivariate analyses. Finally, NT-proBNP had the highest AUC value (88.54) for discriminating DD presence.

Conclusion: Cardiovascular biomarkers represent valuable tools for diastolic dysfunction assessment in the context of CCM. Additional studies focusing mainly on patients with HFpEF are required to validate the performance of these cardiovascular biomarkers in CCM, allowing for an optimal assessment of this unique population.

Biomarkers assessment in patients with Chagas disease and systemic arterial hypertension

Chagas disease (ChD) and systemic arterial hypertension (SAH) are two severe comorbidities that lead to mortality and a reduction in people's quality of life, with an impact on public health. The aim of this study was to quantify the biomarkers of cardiac injury in patients with ChD and SAH. Eighty patients were divided into four groups: 20 hypertensive patients, 20 ChD-hypertensive patients, 20 ChD patients, and 20 normotensive volunteers; all of them came from outpatient's public health services. Among the evaluated markers for cardiac lesions (creatine kinase, creatine kinase-MB isoform, myoglobin, high-sensitive cardiac troponin T[hs-cTnT], B-type natriuretic peptide [BNP], and C-reactive protein), hs-cTnT and BNP were the most appropriate. Importantly, our results showed that the cut off point for hs-cTnT could be < 0.007 ng/mL, which could lead to the early detection of myocardial lesions. The BNP and hs-cTnT levels were high only in the ChD and ChD-hypertensive patient groups, suggesting that Chagas' disease may play an important role in the increase of these biomarkers. ChD patients, hypertensive or not, with cardiac or cardiodigestive involvement presented significantly higher values of hs-cTnT (p < 0.001) and BNP (p = 0.001) than ChD patients with indeterminate and digestive forms, which strengthens the validation of these markers for the follow-up of clinical cardiac form of ChD. This study suggests that the BNP and hs-cTnT can be used as possible indirect biomarkers of cardiac damage. In addition, the reference values of these biomarkers in Chagas and hypertensive cardiomyopathies should be better understood with further studies.

State-of-the-art in host-derived biomarkers of Chagas disease prognosis and early evaluation of anti-Trypanosoma cruzi treatment response

Chagas disease is caused by infection with the parasite Trypanosoma cruzi, which might lead to a chronic disease state and drive to irreversible damage to the heart and/or digestive tract tissues. Endemic in 21 countries in the Americas, it is the neglected disease with a highest burden in the region. Current estimates point at ~6 million people infected, of which ~30% will progress onto the symptomatic tissue disruptive stage. There is no vaccine but there are two anti-parasitic drugs available: benznidazole and nifurtimox. However, their efficacy is variable at the chronic symptomatic stage and both have frequent adverse effects. Since there are no prognosis markers, drugs should be administered to all T. cruzi-infected individuals in the indeterminate and early symptomatic stages. Nowadays, there are no tests-of-cure either, which greatly undermines patients follow-up and the search of safer and more efficacious drugs. Therefore, the identification and validation of biomarkers of disease progression and/or treatment response on which to develop tests of prognosis and/or cure is a major research priority. Both parasite- and host-derived markers have been investigated. In the present manuscript we present an updated outlook of the latter.

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.

Speckle tracking echocardiographic deformation indices in Chagas and idiopathic dilated cardiomyopathy: Incremental prognostic value of longitudinal strain

Background

Chagas cardiomyopathy (CDC) is associated with a poor prognosis compared to other cardiomyopathies. Speckle tracking echocardiography (STE), which provides direct assessment of myocardial fiber deformation, may be useful in predicting prognosis.

Objective

This study assessed STE in CDC and compared with idiopathic cardiomyopathy (IDC), and also examined the incremental prognostic information of STE over left ventricular ejection fraction (LVEF) in these patients.

Methods

We enrolled 112 patients, age of 56.7 ± 11.8 years, 81 with CDC and 31 with IDC. STE indices were obtained at baseline in all patients. The endpoint was a composite of death, hospitalization for heart failure, or need for heart transplantation.

Results

Patients with IDC had worse LV systolic function compared to CDC, with LVEF of 34.5% vs 41.3%, p = 0.004, respectively. After adjustment for LVEF, there were no differences in STE values between CDC and IDC. During a median follow-up of 18.2 months (range, 11 to 22), 26 patients met the composite end point (24%). LV longitudinal strain was a strong predictor of adverse events, incremental to LVEF and E/e' ratio (HR 1.463, 95% CI 1.130–1.894; p = 0.004). The risk of cardiac events increased significantly in patients with GLS > - 12% (log-rank p = 0.035).

Conclusions

STE indices were abnormal in patients with dilated cardiomyopathy, without differences between CDC and IDC. LV longitudinal strain was a powerful predictor of outcome, adding prognostic information beyond that provided by LVEF and E/e' ratio.

Could angiotensin-modulating drugs be relevant for the treatment of Trypanosoma cruzi infection? A systematic review of preclinical and clinical evidence

Although leucocytes are targets of renin-angiotensin system (RAS) effector molecules and RAS-modulating drugs exert immunomodulatory effects, their impact onTrypanosoma cruziinfection remains poorly understood. By using the framework of a systematic review, we integrated the preclinical and clinical evidence to investigate the relevance of angiotensin-inhibiting drugs onT. cruziinfections. From a comprehensive and structured search in biomedical databases, only original studies were analysed. In preclinical and clinical studies, captopril, enalapril and losartan were RAS-modulating drugs used. The mainin vitrofindings indicated that these drugs increased parasite uptake per host cells, IL-12 expression by infected dendritic cells and IFN-γby T lymphocytes, in addition to attenuating IL-10 and IL-17 production by CD8 + T cells. In animal models, reduced parasitaemia, tissue parasitism, leucocytes infiltration and mortality were often observed inT. cruzi-infected animals receiving RAS-modulating drugs. In patients with Chagas’ disease, these drugs exerted a controversial impact on cytokine and hormone levels, and a limited effect on cardiovascular function. Considering a detailed evaluation of reporting and methodological quality, the current preclinical and clinical evidence is at high risk of bias, and we hope that our critical analysis will be useful in mitigating the risk of bias in further studies.

Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement From the American Heart Association

Background:

Chagas disease, resulting from the protozoan Trypanosoma cruzi , is an important cause of heart failure, stroke, arrhythmia, and sudden death. Traditionally regarded as a tropical disease found only in Central America and South America, Chagas disease now affects at least 300 000 residents of the United States and is growing in prevalence in other traditionally nonendemic areas. Healthcare providers and health systems outside of Latin America need to be equipped to recognize, diagnose, and treat Chagas disease and to prevent further disease transmission.

Methods and Results:

The American Heart Association and the Inter-American Society of Cardiology commissioned this statement to increase global awareness among providers who may encounter patients with Chagas disease outside of traditionally endemic environments. In this document, we summarize the most updated information on diagnosis, screening, and treatment of T cruzi infection, focusing primarily on its cardiovascular aspects. This document also provides quick reference tables, highlighting salient considerations for a patient with suspected or confirmed Chagas disease.

Conclusions:

This statement provides a broad summary of current knowledge and practice in the diagnosis and management of Chagas cardiomyopathy. It is our intent that this document will serve to increase the recognition of Chagas cardiomyopathy in low-prevalence areas and to improve care for patients with Chagas heart disease around the world.

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.

Multimodality imaging evaluation of Chagas disease: an expert consensus of Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI)

Aims

To develop a document by Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI) to review and summarize the most recent evidences about the non-invasive assessment of patients with Chagas disease, with the intent to set up a framework for standardized cardiovascular imaging to assess cardiovascular morphologic and functional disturbances, as well as to guide the subsequent process of clinical decision-making.

Methods and results

Chagas disease remains one of the most prevalent infectious diseases in Latin America, and has become a health problem in non-endemic countries. Dilated cardiomyopathy is the most severe manifestation of Chagas disease, which causes substantial disability and early mortality in the socially most productive population leading to a significant economical burden. Prompt and correct diagnosis of Chagas disease requires specialized clinical expertise to recognize the unique features of this disease. The appropriate and efficient use of cardiac imaging is pivotal for diagnosing the cardiac involvement in Chagas disease, to stage the disease, assess patients' prognosis and address management. Echocardiography is the most common imaging modality used to assess, and follow-up patients with Chagas disease. The presence of echocardiographic abnormalities is of utmost importance, since it allows to stage patients according to disease progression. In early stages of cardiac involvement, echocardiography may demonstrate segmental left ventricuar wall motion abnormalities, mainly in the basal segments of inferior, inferolateral walls, and the apex, which cannot be attributed to obstructive coronary artery arteries. The prevalence of segmental wall motion abnormalities varies according to the stage of the disease, reaching about 50% in patients with left ventricular dilatation and dysfunction. Speckle tracking echocardiography allows a more precise and quantitative measurement of the regional myocardial function. Since segmental wall motion abnormalities are frequent in Chagas disease, speckle tracking echocardiography may have an important clinical application in these patients, particularly in the indeterminate forms when abnormalities are more subtle. Speckle tracking echocardiography can also quantify the heterogeneity of systolic contraction, which is associated with the risk of arrhythmic events. Three-dimensional (3D) echocardiography is superior to conventional two-dimensional (2D) echocardiography for assessing more accurately the left ventricular apex and thus to detect apical aneurysms and thrombus in patients in whom ventricular foreshortening is suspected by 2D echocardiography. In addition, 3D echocardiography is more accurate than 2D Simpson s biplane rule for assessing left ventricular volumes and function in patients with significant wall motion abnormalities, including aneurysms with distorted ventricular geometry. Contrast echocardiography has the advantage to enhancement of left ventricular endocardial border, allowing for more accurate detection of ventricular aneurysms and thrombus in Chagas disease. Diastolic dysfunction is an important hallmark of Chagas disease even in its early phases. In general, left ventricular diastolic and systolic dysfunction coexist and isolated diastolic dysfunction is uncommon but may be present in patients with the indeterminate form. Right ventricular dysfunction may be detected early in the disease course, but in general, the clinical manifestations occur late at advanced stages of Chagas cardiomyopathy. Several echocardiographic parameters have been used to assess right ventricular function in Chagas disease, including qualitative evaluation, myocardial performance index, tissue Doppler imaging, tricuspid annular plane systolic excursion, and speckle tracking strain. Cardiac magnetic resonance (CMR) is useful to assess global and regional left ventricular function in patients with Chagas diseases. Myocardial fibrosis is a striking feature of Chagas cardiomyopathy and late gadolinium enhancement (LGE) is used to detect and quantify the extension of myocardial fibrosis. Myocardial fibrosis might have a role in risk stratification of patients with Chagas disease. Limited data are available regarding right ventricular function assessed by CMR in Chagas disease. Radionuclide ventriculography is used for global biventricular function assessment in patients with suspected or definite cardiac involvement in Chagas disease with suboptimal acoustic window and contraindication to CMR. Myocardial perfusion scintigraphy may improve risk stratification to define cardiac involvement in Chagas disease, especially in the patients with devices who cannot be submitted to CMR and in the clinical setting of Chagas patients whose main complaint is atypical chest pain. Detection of reversible ischemic defects predicts further deterioration of left ventricular systolic function and helps to avoid unnecessary cardiac catheterization and coronary angiography.

Conclusion

Cardiac imaging is crucial to detect the cardiac involvement in patients with Chagas disease, stage the disease and stratify patient risk and address management. Unfortunately, most patients live in regions with limited access to imaging methods and point-of-care, simplified protocols, could improve the access of these remote populations to important information that could impact in the clinical management of the disease. Therefore, there are many fields for further research in cardiac imaging in Chagas disease. How to better provide an earlier diagnosis of cardiac involvement and improve patients risk stratification remains to be addressed using different images modalities.

Chagas disease in Europe: A review for the internist in the globalized world

Chagas disease (CD) or American trypanosomiasis identified in 1909 by Carlos Chagas, has become over the last 40years a global health concern due to the huge migration flows from Latin America to Europe, United States, Canada and Japan. In Europe, most migrants from CD-endemic areas are concentrated in Spain, Italy, France, United Kingdom and Switzerland. Pooled seroprevalence studies conducted in Europe show an overall 4.2% prevalence, with the highest infection rates observed among individuals from Bolivia (18.1%). However, in most European countries the disease is neglected with absence of screening programmes and low access to diagnosis and treatment. Physicians working in Europe should also be aware of the risk of autochthonous transmission of Trypanosoma cruzi to newborns by their infected mothers and to recipients of blood or transplanted organs from infected donors. Finally, physicians should be able to recognize and treat the most frequent and serious complications of chronic Chagas disease, namely cardiomyopathy, megacolon and megaesophagus. This review aims to highlights the problem of CD in Europe by reviewing papers published by European researchers on this argument, in order to raise the awareness of internists who are bound to increasingly encounter patients with the disease in their routine daily activities.

Cardioprotective actions of curcumin on the pathogenic NFAT/COX-2/prostaglandin E2 pathway induced during Trypanosoma cruzi infection

BACKGROUND

Diverse cardiovascular signaling routes have been considered critical for Chagas cardiomyopathy caused by the protozoan parasite Trypanosoma cruzi. Along this line, T. cruzi infection and endothelin-1 (ET-1) have been shown to cooperatively activate the Ca²⁺/NFAT cascade in cardiomyocytes, leading to cyclooxygenase type 2 (COX-2) induction and increased release of prostanoids and prohypertrophic peptides.

PURPOSE

To determine whether the well-known cardioprotective and anti-inflammatory effects of curcumin (Cur) could be helpful to interfere with this key machinery for pathogenesis of Chagas myocarditis.

STUDY DESIGN

Cur treatment was evaluated through in vivo studies using a murine model of acute T. cruzi infection and in vitro experiments using ET-1-stimulated and parasite-infected mouse cardiomyocytes.

METHODS

Cur-treated and untreated infected mice were followed-up to estimate survival postinfection and heart tissues from both groups were analyzed for inflammatory infiltration by histopathology, whereas parasite load, induction of arachidonic acid pathway and natriuretic peptide expression were determined by real-time PCR. Molecular analysis of Cur myocardial targets included intracellular calcium measurement, NFAT and COX-2 induction in transfected cells, and assessment of NFAT, COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1) levels by immunoblotting, prostaglandin E₂ (PGE₂) by ELISA, b-type natriuretic peptide (BNP) by real-time PCR, and PGE₂/EP4 receptor/BNP interaction by transwell experiments.

RESULTS

Cur treatment of acute Chagas mice enhanced survival and proved to hinder relevant inflammatory processes in the heart, including leukocyte recruitment, activation of the eicosanoid pathway and BNP overexpression, without modifying parasite burden in the organ. Cur was capable of blocking Ca²⁺-dependent NFATc1 transcriptional activity, COX-2 and mPGES-1 induction, and subsequent PGE₂ production in ET-1-stimulated and parasite-infected cardiomyocytes. Furthermore, the decline of cardiomyocyte-derived prostaglandin levels achieved upon Cur treatment impaired effective PGE₂/EP4 receptor interaction, resulting in attenuated expression of BNP, a strong indicator of cardiac pathogenesis in Chagas disease, in both infected and uninfected cells.

CONCLUSION

Our current study shows a putative mechanism of action of Cur involving inhibition of the Ca²⁺/NFAT-dependent, pathogenic COX-2/mPGES-1/PGE₂ pathway in T. cruzi-infected myocytes, underlying cardioprotection achieved in Cur-treated infected mice. With a view to the limited therapeutic possibilities available, Cur represents a promising approach for the treatment of Chagas heart disease.

Chagas Disease Diagnostic Applications: Present Knowledge and Future Steps

Chagas disease, caused by the protozoan Trypanosoma cruzi, is a lifelong and debilitating illness of major significance throughout Latin America and an emergent threat to global public health. Being a neglected disease, the vast majority of Chagasic patients have limited access to proper diagnosis and treatment, and there is only a marginal investment into R&D for drug and vaccine development. In this context, identification of novel biomarkers able to transcend the current limits of diagnostic methods surfaces as a main priority in Chagas disease applied research. The expectation is that these novel biomarkers will provide reliable, reproducible and accurate results irrespective of the genetic background, infecting parasite strain, stage of disease, and clinical-associated features of Chagasic populations. In addition, they should be able to address other still unmet diagnostic needs, including early detection of congenital T. cruzi transmission, rapid assessment of treatment efficiency or failure, indication/prediction of disease progression and direct parasite typification in clinical samples. The lack of access of poor and neglected populations to essential diagnostics also stresses the necessity of developing new methods operational in point-of-care settings. In summary, emergent diagnostic tests integrating these novel and tailored tools should provide a significant impact on the effectiveness of current intervention schemes and on the clinical management of Chagasic patients. In this chapter, we discuss the present knowledge and possible future steps in Chagas disease diagnostic applications, as well as the opportunity provided by recent advances in high-throughput methods for biomarker discovery.

Chagas cardiomyopathy: The potential effect of benznidazole treatment on diastolic dysfunction and cardiac damage in dogs chronically infected with Trypanosoma cruzi

Cardiac involvement represents the main cause of mortality among patients with Chagas disease, and the relevance of trypanocidal treatment to improving diastolic dysfunction is still doubtful. In the present study, we used a canine model infected with the benznidazole-sensitive Berenice-78 Trypanosoma cruzi strain to verify the efficacy of an etiologic treatment in reducing the parasite load and ameliorating cardiac muscle tissue damage and left ventricular diastolic dysfunction in the chronic phase of the infection. The effect of the treatment on reducing the parasite load was monitored by blood PCR and blood culture assays, and the effect of the treatment on the outcome of heart tissue damage and on diastolic function was evaluated by histopathology and echo Doppler cardiogram. The benefit of the benznidazole-treatment in reducing the parasite burden was demonstrated by a marked decrease in positive blood culture and PCR assay results until 30days post-treatment. At this time, the PCR and blood culture assays yielded negative results for 82% of the treated animals, compared with only 36% of the untreated dogs. However, a progressive increase in the parasite load could be detected in the peripheral blood for one year post-treatment, as evidenced by a progressive increase in positive results for both the PCR and the blood culture assays at follow-up. The parasite load reduction induced by treatment was compatible with the lower degree of tissue damage among animals euthanized in the first month after treatment and with the increased cardiac damage after this period, reaching levels similar to those in untreated animals at the one-year follow-up. The two infected groups also presented similar, significantly smaller values for early tissue septal velocity (E' SIV) than the non-infected dogs did at this later time. Moreover, in the treated animals, an increase in the E/E' septal tissue filling pressure ratio was observed when compared with basal values as well as with values in non-infected dogs. These findings strongly suggest that the temporary reduction in the parasite load that was induced by benznidazole treatment was not able to prevent myocardial lesions and diastolic dysfunction for long after treatment.

Chagas Cardiomyopathy: Usefulness of EKG and Echocardiogram in a Non-Endemic Country

BACKGROUND

Chagas disease (CD) is a major cause of cardiomyopathy in Latin America, and migration movements have now spread the disease worldwide. However, data regarding Chagas cardiomyopathy (CC) and the usefulness of echocardiography in non endemic countries are still scarce.

METHODS AND RESULTS

We selected 485 patients in the chronic phase of CD from two Spanish settings. Data from physical examination, electrocardiogram (EKG), x-ray, and two dimensional transthoracic echocardiogram were recorded. Trypanosoma cruzi DNA was assessed by PCR in peripheral blood. Patients were stratified according to the Kuschnir classification and a combination of echocardiogram and electrocardiogram findings. Patients mainly came from Bolivia (459; 94.6%). One hundred and forty three patients (31.5%) had at least one electrocardiogram abnormality. Twenty seven patients (5.3%) had an abnormal echocardiography. Patients with abnormal echocardiography were older (47 (IQR 38-57) years vs 41 (IQR 38-57) years); p = 0.019) and there was a greater proportion of males (66.7% vs 29.7%); p<0.001). Among echocardiographic variables, diastolic dysfunction was associated with poor cardiac status. In the multivariate analysis, abnormal EKG and gender were associated with abnormal echocardiography. Echocardiography may be spared for males under 30 and females under 45 years old with normal EKG as the likelihood of having an abnormal echocardiography is minimal. Association between T. cruzi DNA in the peripheral blood and cardiac involvement was not observed.

CONCLUSION

CC rates in the studied population are low. Age and sex are important determinants for the development of CC, and with the EKG should guide echocardiogram performance.

Inflammatory and cardiac biomarkers are differentially expressed in clinical stages of Chagas disease

BACKGROUND

Chagas disease has a long clinically silent period following Trypanosoma cruzi infection and before development of overt clinical pathology; detectable biomarkers of infection and pathogenesis are urgently needed. We tested 22 biomarkers known to be associated with cardiomyopathy to evaluate if a biomarker signature could successfully classify T. cruzi seropositive subjects into clinical Chagas disease stage groups.

METHODS

This cross-sectional retrospective case-control study enrolled T. cruzi seropositive blood donors (BD) who were further characterized as having chronic Chagas cardiomyopathy (CC-BD) or not (nonCC-BD) and seronegative (SN) control donors; we also included clinically diagnosed Chagas cardiomyopathy patients (CC-P). All subjects underwent a health history questionnaire, medical examination, electro- and echocardiograms (ECG and Echo) and phlebotomy. Biomarkers were measured on blinded samples by luminex bead array and Ortho VITROS.

RESULTS

A clear biomarker pattern was observed only in more severe cardiac disease; this pattern included significantly elevated levels of inflammatory cytokines IFN-γ, IL-6, IL-10 and TNF-α and soluble cardiovascular disease biomarkers CK-MB, troponin, myoglobin, VCAM and NTproBNP while there were lower levels of MPO, PAI-1, and MCP-1. The markers determined to be the most predictive of disease by ROC curve analysis were NTproBNP and T. cruzi PCR status.

CONCLUSIONS

Although many biomarkers demonstrated increased or decreased concentrations among the clinical forms of Chagas disease, NTproBNP and T. cruzi PCR were the only tests that would independently be of clinical value for disease staging, in concert with ECG, Echo and clinical assessments.

Left Atrial Function in Patients with Chronic Chagasic Cardiomyopathy

BACKGROUND

Chagas disease is a cause of dilated cardiomyopathy, and information about left atrial (LA) function in this disease still lacks.

OBJECTIVE

To assess the different LA functions (reservoir, conduit and pump functions) and their correlation with the echocardiographic parameters of left ventricular (LV) systolic and diastolic functions.

METHODS

10 control subjects (CG), and patients with Chagas disease as follows: 26 with the indeterminate form (GI); 30 with ECG alterations (GII); and 19 with LV dysfunction (GIII). All patients underwent M-mode and two-dimensional echocardiography, pulsed-wave Doppler and tissue Doppler imaging.

RESULTS

Reservoir function (Total Emptying Fraction: TEF): (p <0.0001), lower in GIII as compared to CG (p = 0.003), GI (p <0.001) and GII (p <0.001). Conduit function (Passive Emptying Fraction: PEF): (p = 0.004), lower in GIII (GIII and CG, p = 0.06; GI and GII, p = 0.06; and GII and GIII, p = 0.07). Pump function (Active Emptying Fraction: AEF): (p = 0.0001), lower in GIII as compared to CG (p = 0.05), GI (p<0.0001) and GII (p = 0.002). There was a negative correlation of E/e' (average) with the reservoir and pump functions (TEF and AEF), and a positive correlation of e' (average) with s' wave (both septal and lateral walls) and the reservoir, conduit and pump LA functions.

CONCLUSION

An impairment of LA functions in Chagas cardiomyopathy was observed.

Early detection of left ventricular contractility abnormalities by two-dimensional speckle tracking strain in Chagas’ disease

BACKGROUND

Chagas' disease is an important cause of heart failure, and early identification of cardiac involvement may help to identify patients at risk for disease progression. Two-dimensional (2D) speckle tracking (ST) strain seems to be a useful tool to detect incipient ventricular dysfunction. This study aims to analyze if 2D strain can detect contractility abnormalities in asymptomatic patients with Chagas' disease.

METHODS

Seventy-eight asymptomatic Chagas' disease patients (46% male; age 44.7 ± 8.6 years) with normal cardiovascular exams and a control group of 38 healthy subjects (58% male; age 44.1 ± 9.2 years) were included in the study. Using 2D strain software, left ventricular (LV) end-systolic longitudinal, radial, and circumferential strain were measured. Global right ventricular (RV) longitudinal strain was also assessed.

RESULTS

Echocardiographic parameters of LV systolic and diastolic function were similar between patients and controls. 2D longitudinal strain in the basal inferior, and inferoseptal walls, as well as apical segment of the inferolateral wall were lower in patients compared with controls. 2D radial strain was reduced in several segments of the LV walls as well as the global radial strain. 2D circumferential strain at the basal segment of the anterior wall showed a lower value in patients compared with controls, whereas global circumferential strain was similar between patients and controls. 2D RV strain did not differ between groups.

CONCLUSION

In a subgroup of asymptomatic patients with Chagas' disease without evident cardiac involvement, 2D strain was reduced compared with healthy individuals, suggesting incipient LV dysfunction in these patients. 2D ST strain has the potential for detecting early myocardial impairment in the setting of Chagas' disease.

Biomarkers of therapeutic responses in chronic Chagas disease: state of the art and future perspectives

The definition of a biomarker provided by the World Health Organization is any substance, structure, or process that can be measured in the body, or its products and influence, or predict the incidence or outcome of disease. Currently, the lack of prognosis and progression markers for chronic Chagas disease has posed limitations for testing new drugs to treat this neglected disease. Several molecules and techniques to detect biomarkers in Trypanosoma cruzi-infected patients have been proposed to assess whether specific treatment with benznidazole or nifurtimox is effective. Isolated proteins or protein groups from different T. cruzi stages and parasite-derived glycoproteins and synthetic neoglycoconjugates have been demonstrated to be useful for this purpose, as have nucleic acid amplification techniques. The amplification of T. cruzi DNA using the real-time polymerase chain reaction method is the leading test for assessing responses to treatment in a short period of time. Biochemical biomarkers have been tested early after specific treatment. Cytokines and surface markers represent promising molecules for the characterisation of host cellular responses, but need to be further assessed.

Circulating serum markers and QRS scar score in Chagas cardiomyopathy

Approximately 8 million people have Trypanosoma cruzi infection, and nearly 30% will manifest Chagas cardiomyopathy (CC). Identification of reliable early indicators of CC risk would enable prioritization of treatment to those with the highest probability of future disease. Serum markers and electrocardiogram (EKG) changes were measured in 68 T. cruzi-infected individuals in various stages of cardiac disease and 17 individuals without T. cruzi infection or cardiac disease. T. cruzi-infected individuals were assigned to stage A (normal EKG/chest x-ray [CXR]), B (abnormal EKG/normal CXR), or C (abnormal EKG/cardiac structural changes). Ten serum markers were measured using enzyme-linked immunosorbent assay (ELISA)/Luminex, and QRS scores were calculated. Higher concentrations of transforming growth factor-β1 (TGFβ1), and TGFβ2 were associated with stage B compared with stage A. Matrix Metalloproteinase 2 (MMP2), Tissue Inhibitors of MMP 1, QRS score, and Brain Natriuretic Protein rose progressively with increasing CC severity. Elevated levels of several markers of cardiac damage and inflammation are seen in early CC and warrant additional evaluation in longitudinal studies.

Biomarkers in Trypanosoma cruzi-infected and uninfected individuals with varying severity of cardiomyopathy in Santa Cruz, Bolivia

Background

Twenty to thirty percent of persons with Trypanosoma cruzi infection eventually develop cardiomyopathy. If an early indicator were to be identified and validated in longitudinal studies, this could enable treatment to be prioritized for those at highest risk. We evaluated cardiac and extracellular matrix remodeling markers across cardiac stages in T. cruzi infected (Tc+) and uninfected (Tc−) individuals.

Methods

Participants were recruited in a public hospital in Santa Cruz, Bolivia and assigned cardiac severity stages by electrocardiogram and echocardiogram. BNP, NTproBNP, CKMB, troponin I, MMP-2, MMP-9, TIMP-1, TIMP-2, TGFb1, and TGFb2 were measured in specimens from 265 individuals using multiplex bead systems. Biomarker levels were compared between Tc+ and Tc− groups, and across cardiac stages. Receivers operating characteristic (ROC) curves were created; for markers with area under curve>0.60, logistic regression was performed.

Results

Analyses stratified by cardiac stage showed no significant differences in biomarker levels by Tc infection status. Among Tc+ individuals, those with cardiac insufficiency had higher levels of BNP, NTproBNP, troponin I, MMP-2, TIMP-1, and TIMP-2 than those with normal ejection fraction and left ventricular diameter. No individual marker distinguished between the two earliest Tc+ stages, but in ROC-based analyses, MMP-2/MMP-9 ratio was significantly higher in those with than those without ECG abnormalities.

Conclusions

BNP, NTproBNP, troponin I, MMP-2, TIMP-1, and TIMP-2 levels rose with increasing severity stage but did not distinguish between Chagas cardiomyopathy and other cardiomyopathies. Among Tc+ individuals without cardiac insufficiency, only the MMP-2/MMP-9 ratio differed between those with and without ECG changes.

In Chagas disease, a parasitic disease found primarily in Central and South America, individuals are chronically infected with the parasite Trypanosoma cruzi. A few decades after initial infection, 20–30% of infected individuals will develop cardiac disease. If we were able to predict which individuals would progress to cardiac disease, treatment in these low resource areas could be targeted to those at highest risk. The ideal transition point to identify those at risk would be as individuals progress from a normal electrocardiogram to an abnormal electrocardiogram, the first step in the progression of cardiac disease. Previous studies have suggested a group of serum biomarkers able to differentiate between these stages of disease. However, our larger and more comprehensive study finds that none of the ten cardiac and remodeling biomarkers we tested are able to distinguish between healthy individuals and those with the earliest evidence of cardiac disease. We did find cardiac biomarkers to be elevated in those with severe cardiac disease as expected in both T. cruzi infected and uninfected individuals.

Clinical and echocardiographic predictors of mortality in chagasic cardiomyopathy--systematic review

Diagnosis, prognosis and evaluation of death risk in Chagas cardiomyopathy still constitute a challenge due to the diversity of manifestations, which determine the importance of using echocardiography, tissue Doppler and biomarkers. To evaluate, within a systematic review, clinical and echocardiographic profiles of patients with chronic chagasic cardiomyopathy, which may be related to worse prognosis and major mortality risk. To perform the systematic review, we used Medline (via PubMed), LILACS and SciELO databases to identify 82 articles published from 1991 to 2012, with the following descriptors: echocardiography, mortality and Chagas disease. We selected 31 original articles, involving diagnostic and prognostic methods. The importance of Chagas disease has increased due to its emergence in Europe and United States, but most evidence came from Brazil. Among the predictors of worse prognosis and higher mortality risk are morphological and functional alterations in the left and right ventricles, evaluated by conventional echocardiography and tissue Doppler, as well as the increase in brain natriuretic peptide and troponin I concentrations. Recently, the evaluations of dyssynchrony, dysautonomia, as well as strain, strain rate and myocardial twisting were added to the diagnostic arsenal for the early differentiation of Chagas cardiomyopathy. Developments in imaging and biochemical diagnostic procedures have enabled more detailed cardiac evaluations, which demonstrate the early involvement of both ventricles, allowing a more accurate assessment of the mortality risk in Chagas disease.

[Cardiovascular disease: a view from global health perspective]

Globalization has facilitated the movement of large number of people around the world, leading modern clinicians to attend patients with rare or forgotten diseases. In the last few years many doctors are working in developing countries as volunteers or expatriates. The aim of this article is to summarize the basic epidemiological, clinical and therapeutic knowledge of the main cardiovascular diseases that a medical doctor from a developed country may attend in a tropical rural hospital, or with challenging diseases in patients coming from developing countries.

Chagas disease: an overview of clinical and epidemiological aspects

Chagas disease, caused by the parasite Trypanosoma cruzi, is a serious health problem in Latin America and is an emerging disease in non-endemic countries. In recent decades, the epidemiological profile of the disease has changed due to new patterns of immigration and successful control in its transmission, leading to the urbanization and globalization of the disease. Dilated cardiomyopathy is the most important and severe manifestation of human chronic Chagas disease and is characterized by heart failure, ventricular arrhythmias, heart blocks, thromboembolic phenomena, and sudden death. This article will present an overview of the clinical and epidemiological aspects of Chagas disease. It will focus on several clinical aspects of the disease, such as chronic Chagas disease without detectable cardiac pathology, as well as dysautonomia, some specific features, and the principles of treatment of chronic cardiomyopathy.

Multicenter epidemiological and clinical study on imported Chagas diseases in Alicante, Spain

Recently, there has been an increase in the number of patients with Chagas disease outside of areas that are generally considered endemic. The aim of this investigation is to describe the clinical profile of a series of patients with Chagas disease in Alicante, Spain, which is a province located on the coast of the Mediterranean Sea. This study was performed at four general hospitals in Alicante between January 2002 and May 2011. A total of 128 patients from seven countries were diagnosed with Trypanosoma cruzi. The main country of origin of these patients was Bolivia (n5101; 78.9%), and the median of age of these patients was 35 years (range: 0–72 years). Four (3.3%) patients were children under 14 years of age, and 81 (63.3%) were female. Polymerase chain reaction (PCR) was used to analyze 106 patients, 66.0% of whom demonstrated positive PCR results. Visceral involvement was diagnosed in 26.8%: 24.1% demonstrated cardiac involvement, 0.9% demonstrated gastrointestinal involvement, 0.9% demonstrated cardiac and gastrointestinal involvement, and 0.9% demonstrated involvement of the central nervous system. Syncope was found to be associated with cardiomyopathy (28.0% versus 5.2%) (odds ratio: 6.5; 95% confidence interval: 1.5–27.1). Seventy-six patients received treatment with benznidazole, of whom 57 (75.0%) completed the treatment course without significant adverse events and 17.1% discontinued benznidazole due to adverse events. In total, 50% of patients experienced documented adverse reactions. Among patients with positive PCR results before treatment, all demonstrated negative PCR results following treatment. In conclusion, majority of our patients were female Bolivians immigrants, one of four of our patients demonstrated cardiac involvement, and treatment tolerance was poor. It is important to improve the clinical and epidemiological knowledge of Chagas disease in nonendemic with additional multicenter studies in order to determine the magnitude of this problem and provide improved public health and health resource planning.

Imagining the future of diagnostic imaging

Cardiovascular imaging has become essential to achieving a better understanding of cardiovascular diseases. Due to the advent of new technology and the refinement of existing technologies, imaging's role has extended into the biological, functional, and hemodynamic diagnosis of multiple pathophysiologic processes. Current and future trends in cardiovascular imaging will focus on improving early diagnosis of vascular disease, so as to be able to promote cardiovascular health, and on its development as a useful tool in clinical decision-making. Imaging is also increasingly used to quantify the effect of novel therapies. The rapid development of molecular imaging and fusion imaging techniques improves our understanding of cardiovascular processes from the molecular and cellular points of view and makes it possible to design and test new preventive interventions. The proliferation and integration of imaging techniques in different clinical areas and their role in "translational imaging" plays an important part in the implementation of personalized therapeutic and preventive management strategies for patients with cardiovascular disease.

Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects

Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

Diagnosis and management of Chagas disease and cardiomyopathy

Chagas cardiomyopathy is the most severe and life-threatening manifestation of human Chagas disease--a 'neglected' tropical disease caused by the protozoan parasite Trypanosoma cruzi. The disease is endemic in all continental Latin American countries, but has become a worldwide problem because of migration of infected individuals to developed countries, mainly in Europe and North America. Chagas cardiomyopathy results from the combined effects of persistent parasitism, parasite-driven tissue inflammation, microvascular and neurogenic dysfunction, and autoimmune responses triggered by the infection. Clinical presentation varies widely according to the extent of myocardial damage, and manifests mainly as three basic syndromes that can coexist in an individual patient: heart failure, cardiac arrhythmia, and thromboembolism. NYHA functional class, left ventricular systolic function, and nonsustained ventricular tachycardia are important prognostic markers of the risk of death. Management of Chagas cardiomyopathy focuses on the treatment of the three main syndromes. The use of β-blockers in patients with Chagas disease and heart failure is safe, well tolerated, and should be encouraged. Most specialists and international institutions now recommend specific antitrypanosomal treatment of patients with chronic Chagas disease, even in the absence of evidence obtained from randomized clinical trials. Further research on the management of patients with Chagas cardiomyopathy is necessary.

[A clinical and epidemiological study of the Trypanosoma cruzi infected population in the north metropolitan area of Barcelona]

BACKGROUND

As an inevitable consequence of Latin American immigration to Europe, Spain and other European countries, it is necessary to confront the approach to cases of Chagas infection/disease for which, epidemiologically, there are more questions than answers. This study has aimed to describe all the Chagas-infected population in the north metropolitan area of Barcelona (406,000 inhabitants).

PATIENTS AND METHODS

A prospective and multicentric study was performed in 3 hospitals and 1 International Health Unit. It included all patients with Trypanosoma cruzi positive serology, regardless of the requesting reason.Results The 139 diagnosed cases represent an annual incidence of: a) 0.68/10,000 inhabitants and, b) 73.2/10,000 immigrants coming from endemic zones. Of the patients, 80 (57.6%) had alterations in some complementary tests: cardiologic 62 (44.6%), digestive 38 (27.3%) and 20 (14.4%) both. According to the Brazilian Consensus of Chagas cardiomyopathy, they were classified as: 0=84 (60.4%); a=40 (28.7%); b1=4 (2.9%), b2=10 (7.2%) and c/d=1 (0.7%). Treatment with benznidazole (5mg/kg/24h for 60 days) was prescribed in 116 (83.4%) patients, 89 (76.7%) of whom completed it. Secondary effects were recorded in 56 (50.9%), which made it necessary to withdraw it in 21 (19.1%).

CONCLUSIONS

Fewer cases of Chagas infection/disease than expected have been diagnosed in the North Metropolitan area of Barcelona. The series contains a high number of patients and there may be an elevated number of immigrants from endemic zones who have the asymptomatic chronic stages of the infection and who were unaware of their condition.

Advances and challenges towards a vaccine against Chagas disease

Chagas disease is major public health problem, affecting nearly 10 million people, characterized by cardiac alterations leading to congestive heart failure and death of 20-40% of the patients infected with Trypanosoma cruzi, the protozoan parasite responsible for the disease. A vaccine would be key to improve disease control and we review here the recent advances and challenges of a T. cruzi vaccine. There is a growing consensus that a protective immune response requires the activation of a Th1 immune profile, with the stimulation of CD8 (+) T cells. Several vacines types, including recombinant proteins, DNA and viral vectors, as well as heterologous prime-boost combinations, have been found immunogenic and protective in mouse models, providing proof-of-concept data on the feasibility of a preventive or therapeutic vaccine to control a T. cruzi infection. However, several challenges such as better end-points, safety issues and trial design need to be addressed for further vaccine development to proceed.

Myocardial deformation analysis in Chagas heart disease with the use of speckle tracking echocardiography

BACKGROUND

Assessment of myocardial deformation in Chagas disease may help us to better understand the disease pathophysiology and to detect early myocardial involvement. We aimed to characterize myocardial deformation in patients in different forms of Chagas disease and, specifically, assess differences between patients in the indeterminate form and controls.

METHODS AND RESULTS

Speckle tracking echocardiography was performed in 98 subjects (22 with Chagas cardiomyopathy, 32 in the indeterminate form, and 44 control subjects) to quantify global and segmental left ventricular (LV) radial strain (RS), circumferential strain (CS), and longitudinal strain (LS). In a subset of patients from the indeterminate and control groups (n = 25), LV peak systolic twist and untwisting velocities were additionally assessed. Global RS, CS, and LS showed a significant decreasing trend across groups. Patients in the indeterminate form had significantly lower global RS and RS in the midinferior segment (median 39.8% vs 49.3% [P = .046] and 44.0% vs 56.0% [P = .038], respectively) and lower twist and untwisting velocity (P < .05 for both) compared with control subjects.

CONCLUSION

Evaluation of myocardial deformation, particularly of RS, appears to be a sensitive technique for detection of myocardial involvement in patients in the indeterminate form and provides insights into the still unrevealed pathophysiology of Chagas heart involvement.

Myocardial involvement in Chagas disease: insights from cardiac magnetic resonance

BACKGROUND

Chagas' disease is becoming a public health problem in Europe because of migratory movements. Cardiac magnetic resonance (CMR) has emerged as a non-invasive tool to assess cardiac tissue characteristics. There is scarce data available on CMR in patients with Chagas' disease.

OBJECTIVE

To describe CMR findings in patients with Chagas' disease living in a non-endemic area focusing on differentiation from other cardiomyopathies and relation with clinical status.

METHODS AND RESULTS

Sixty-seven Chagas' disease patients divided into 3 groups-group 1 (indeterminate form: positive serology without ECG or 2D-echocardiographic abnormalities; N = 27), group 2 (ECG abnormalities of Chagas' disease but normal 2D-echocardiography; N = 19), and group 3 (regional wall motion abnormalities, LV end-diastolic diameter >55 mm or LV ejection fraction <50% on echocardiography; N = 21)--were studied. The presence of wall motion abnormalities and delayed enhancement (DE) by CMR was more frequent in the inferolateral and apical segments. DE distribution in the myocardial wall was heterogeneous (subendocardial 26.8%, midwall 14.0%, subepicardial 22.6%, and transmural 36.0% of total segments with DE) and related to larger cardiac chambers and worse systolic function.

CONCLUSION

Pattern of DE in Chagas' disease may mimic that of both ischemic and nonischemic cardiomyopathies, with especial predilection for the apical and inferolateral segments of the left ventricle. These findings support that myocardial involvement in chronic Chagas' cardiomyopathy (CCC) may be due to both microvascular disturbances and chronic myocarditis and may favor CCC in the differential diagnosis of patients with compatible epidemiological history and heart failure of uncertain etiology.

[Endothelial function and high-sensitivity C-reactive protein levels in patients with Chagas disease living in a nonendemic area]

INTRODUCTION AND OBJECTIVES

The number of patients with Chagas disease in Spain has increased significantly. Chronic inflammation and endothelial dysfunction have been considered among the physiopathological mechanisms of Chagas heart disease. However, there have been conflicting data from clinical studies. Our purpose was to assess endothelial function and systemic levels of nitric oxide and high-sensitivity C-reactive protein in patients with the indeterminate form and with chronic Chagas cardiomyopathy living in a nonendemic area.

METHODS

Flow-mediated endothelium-dependent vasodilatation and nitroglycerin-mediated vasodilatation were assessed with high-resolution ultrasound of the brachial artery in 98 subjects (32 with the indeterminate form, 22 with chronic Chagas cardiomyopathy and 44 controls). Nitric oxide and high-sensitivity C-reactive protein levels were measured in peripheral venous blood.

RESULTS

Mean age was 37.6 ± 10.2 years and 60% were female. Nitroglycerin-mediated vasodilatation was significantly reduced in chronic Chagas cardiomyopathy compared to controls (median 16.8% vs 22.5%; P=.03). No significant differences were observed in flow-mediated vasodilatation and nitric oxide levels, although a trend towards lower flow-mediated vasodilatation after correction by baseline brachial artery diameter was observed in chronic Chagas cardiomyopathy. Levels of C-reactive protein were significantly higher in patients with the indeterminate form and with Chagas cardiomyopathy compared with controls (P<.05).

CONCLUSIONS

Reduced nitroglycerin-mediated vasodilatation suggesting dysfunction of vascular smooth muscle cells was found in patients with chronic Chagas cardiomyopathy living in a nonendemic area. Higher C-reactive protein levels were observed in the indeterminate form and early stages of chronic Chagas cardiomyopathy, which could be related to the inflammatory response to the infection or early cardiovascular involvement.