Electrocardiographic abnormalities in elderly Chagas disease patients: 10-year follow-up of the Bambui Cohort Study of Aging

Cardiac involvement in Chagas disease and African trypanosomiasis

Trypanosomiases are diseases caused by various species of protozoan parasite in the genus Trypanosoma, each presenting with distinct clinical manifestations and prognoses. Infections can affect multiple organs, with Trypanosoma cruzi predominantly affecting the heart and digestive system, leading to American trypanosomiasis or Chagas disease, and Trypanosoma brucei primarily causing a disease of the central nervous system known as human African trypanosomiasis or sleeping sickness. In this Review, we discuss the effects of these infections on the heart, with particular emphasis on Chagas disease, which continues to be a leading cause of cardiomyopathy in Latin America. The epidemiology of Chagas disease has changed substantially since 1990 owing to the emigration of over 30 million Latin American citizens, primarily to Europe and the USA. This movement of people has led to the global dissemination of individuals infected with T. cruzi. Therefore, cardiologists worldwide must familiarize themselves with Chagas disease and the severe, chronic manifestation - Chagas cardiomyopathy - because of the expanded prevalence of this disease beyond traditional endemic regions.

Combination of Tele-Cardiology Tools for Cardiovascular Risk Stratification in Primary Care: Data from the PROVAR+ Study

BACKGROUND

Tele-cardiology tools are valuable strategies to improve risk stratification.

OBJECTIVE

We aimed to evaluate the accuracy of tele-electrocardiography (ECG) to predict abnormalities in screening echocardiography (echo) in primary care (PC).

METHODS

In 17 months, 6 health providers at 16 PC units were trained on simplified handheld echo protocols. Tele-ECGs were recorded for final diagnosis by a cardiologist. Consented patients with major ECG abnormalities by the Minnesota code, and a 1:5 sample of normal individuals underwent clinical questionnaire and screening echo interpreted remotely. Major heart disease was defined as moderate/severe valve disease, ventricular dysfunction/hypertrophy, pericardial effusion, or wall-motion abnormalities. Association between major ECG and echo abnormalities was assessed by logistic regression as follows: 1) unadjusted model; 2) model 1 adjusted for age/sex; 3) model 2 plus risk factors (hypertension/diabetes); 4) model 3 plus history of cardiovascular disease (Chagas/rheumatic heart disease/ischemic heart disease/stroke/heart failure). P-values < 0.05 were considered significant.

RESULTS

A total 1,411 patients underwent echo; 1,149 (81%) had major ECG abnormalities. Median age was 67 (IQR 60 to 74) years, and 51.4% were male. Major ECG abnormalities were associated with a 2.4-fold chance of major heart disease on echo in bivariate analysis (OR = 2.42 [95% CI 1.76 to 3.39]), and remained significant after adjustments in models (p < 0.001) 2 (OR = 2.57 [95% CI 1.84 to 3.65]), model 3 (OR = 2.52 [95% CI 1.80 to3.58]), and model 4 (OR = 2.23 [95%CI 1.59 to 3.19]). Age, male sex, heart failure, and ischemic heart disease were also independent predictors of major heart disease on echo.

CONCLUSIONS

Tele-ECG abnormalities increased the likelihood of major heart disease on screening echo, even after adjustments for demographic and clinical variables.

Spatio-temporal distribution of hospitalizations for chronic Chagas disease and risk factors associated with in-hospital mortality and surgical intervention in Chile

Chagas disease (CD) is a neglected parasitic zoonotic disease that affects over 6 million people worldwide. We conducted a retrospective study to analyze the spatiotemporal trends and risk factors for hospitalization rates of CD with cardiac and digestive diagnoses in Chile. We used the Mann-Kendall analysis for temporal trends, Global Moran's Index, and Local Indicators of Spatial Association to identify spatial autocorrelation, and regression models to determine the risk factors associated with in-hospital mortality and surgical intervention. Between 2010 and 2020, a total of 654 hospitalizations were reported, corresponding to 527 individuals. The hospitalization rate steadily decreased over the years (t = -0.636; p = 0.009). The Global Moran's I for the study period showed a positive spatial autocorrelation for hospitalization municipality and for residence municipality of CD patients (I = 0.25, p<0.001 and I = 0.45, p<0.001 respectively), indicating a clustering of hospitalizations in northern municipalities. The most frequent diagnosis was a chronic CD with digestive system involvement (55.8%) followed by a chronic CD with heart involvement (44.2%). The highest percentage of hospital discharges was observed among males (56.9%) and in the 60-79 age group (52.7%). In-hospital mortality risk was higher with increasing age (OR = 1.04), and in patients with cardiac involvement (OR = 2.3), whereas factors associated with the risk of undergoing a surgical intervention were sex (OR = 1.6) and diagnosis of CD with digestive involvement (OR = 4.4). The findings of this study indicate that CD is still a significant public health burden in Chile. Efforts should focus on improving access to timely diagnoses and treatment, reducing disease progression and hospitalization burden, and supporting clinicians in preventing complications and deaths.

Gastrointestinal Manifestations of Chagas Disease: A Systematic Review with Meta-Analysis

The aims of this study were to estimate the prevalence of gastrointestinal manifestations among individuals with positive serology for Chagas disease (ChD) and to describe the clinical gastrointestinal manifestations of the disease. A systematic review with meta-analysis was conducted based on the criteria and recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The PubMed, Scopus, Virtual Health Library, Web of Science, and Embase databases were used to search for evidence. Two reviewers independently selected eligible articles and extracted data. RStudio® software was used for the meta-analysis. For subgroup analysis, the studies were divided according to the origin of the individuals included: 1) individuals from health units were included in the health care service prevalence analysis, and 2) individuals from the general population were included in the population prevalence analysis. A total of 2,570 articles were identified, but after removal of duplicates and application of inclusion criteria, 24 articles were included and 21 were part of the meta-analysis. Most of the studies were conducted in Brazil. Radiological diagnosis was the most frequent method used to identify the gastrointestinal clinical form. The combined effect of meta-analysis studies showed a prevalence of gastrointestinal manifestations in individuals with ChD of 12% (95% CI, 8.0-17.0%). In subgroup analysis, the prevalence for studies involving health care services was 16% (95% CI, 11.0-23.0%), while the prevalence for population-based studies was 9% (95% CI, 5.0-15.0%). Megaesophagus and megacolon were the main forms of ChD presentation in the gastrointestinal form. The prevalence of gastrointestinal manifestations of ChD was 12%. Knowing the prevalence of ChD in its gastrointestinal form is an important step in planning health actions for these patients.

Immunologic changes are detectable in the peripheral blood transcriptome of clinically asymptomatic Chagas cardiomyopathy patients

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a neglected parasitic disease that affects approximately 6 million individuals worldwide. Of those infected, 20-30% will go on to develop chronic Chagas cardiomyopathy (CCC), and ultimately many of these individuals will progress to advanced heart failure. The mechanism by which this progression occurs is poorly understood, as few studies have focused on early CCC. In this study, we sought to understand the physiologic changes associated with T. cruzi infection and the development of CCC. We analyzed gene expression in the peripheral blood of asymptomatic Chagas patients with early structural heart disease, Chagas patients without any signs or symptoms of disease, and Chagas-negative patients with and without early structural heart disease. Our analysis shows that early CCC was associated with a downregulation of various peripheral immune response genes, with gene expression changes suggestive of reduced antigen presentation and T cell activation. Notably, these genes and processes were distinct from those of early cardiomyopathy in Chagas-negative patients, suggesting that the processes mediating CCC may be unique from those mediating progression to other cardiomyopathies. This work highlights the importance of the immune response in early CCC, providing insight into the early pathogenesis of this disease. The changes we have identified may serve as biomarkers of progression and could inform strategies for the treatment of CCC in its early stages, before significant cardiac damage has occurred.

Screening for Chagas disease from the electrocardiogram using a deep neural network

BACKGROUND

Worldwide, it is estimated that over 6 million people are infected with Chagas disease (ChD). It is a neglected disease that can lead to severe heart conditions in its chronic phase. While early treatment can avoid complications, the early-stage detection rate is low. We explore the use of deep neural networks to detect ChD from electrocardiograms (ECGs) to aid in the early detection of the disease.

METHODS

We employ a convolutional neural network model that uses 12-lead ECG data to compute the probability of a ChD diagnosis. Our model is developed using two datasets which jointly comprise over two million entries from Brazilian patients: The SaMi-Trop study focusing on ChD patients, enriched with data from the CODE study from the general population. The model's performance is evaluated on two external datasets: the REDS-II, a study focused on ChD with 631 patients, and the ELSA-Brasil study, with 13,739 civil servant patients.

FINDINGS

Evaluating our model, we obtain an AUC-ROC of 0.80 (CI 95% 0.79-0.82) for the validation set (samples from CODE and SaMi-Trop), and in external validation datasets: 0.68 (CI 95% 0.63-0.71) for REDS-II and 0.59 (CI 95% 0.56-0.63) for ELSA-Brasil. In the latter, we report a sensitivity of 0.52 (CI 95% 0.47-0.57) and 0.36 (CI 95% 0.30-0.42) and a specificity of 0.77 (CI 95% 0.72-0.81) and 0.76 (CI 95% 0.75-0.77), respectively. Additionally, when considering only patients with Chagas cardiomyopathy as positive, the model achieved an AUC-ROC of 0.82 (CI 95% 0.77-0.86) for REDS-II and 0.77 (CI 95% 0.68-0.85) for ELSA-Brasil.

INTERPRETATION

The neural network detects chronic Chagas cardiomyopathy (CCC) from ECG-with weaker performance for early-stage cases. Future work should focus on curating large higher-quality datasets. The CODE dataset, our largest development dataset includes self-reported and therefore less reliable labels, limiting performance for non-CCC patients. Our findings can improve ChD detection and treatment, particularly in high-prevalence areas.

The evolution of electrocardiographic abnormalities in the elderly with Chagas disease during 14 years of follow-up: The Bambui Cohort Study of Aging

BACKGROUND

The natural history of Chagas disease (ChD) in older ages is largely unknown, and it is a matter of controversy if the disease continues to progress in the elderly.

OBJECTIVE

To investigate the evolution of electrocardiographic abnormalities in T. cruzi chronically infected community-dwelling elderly compared to non-infected (NChD) subjects and how it affects this population's survival in a follow-up of 14 years.

METHODS AND RESULTS

A 12-lead ECG of each individual of the Bambui Cohort Study of Aging was obtained in 1997, 2002, and 2008, and the abnormalities were classified using the Minnesota Code. The influence of ChD on the ECG evolution was assessed by semi-competing risks considering a new ECG abnormality as the primary event and death as the terminal event. A Cox regression model to evaluate the population survival was conducted at a landmark point of 5.5 years. The individuals of both groups were compared according to the following categories: Normal, Maintained, New, and More by the development of ECG major abnormalities between 1997 and 2002. Among the participants, the ChD group had 557 individuals (median age: 68 years) and NChD group had 905 individuals (median age: 67 years). ChD was associated with a higher risk of development of a new ECG abnormality [HR: 2.89 (95% CI 2.28-3.67)]. The development of a new major ECG abnormality increases the risk of death ChD patients compared to those that maintain a normal ECG [HR: 1.93 (95% CI 1.02-3.65)].

CONCLUSION

ChD is still associated with a higher risk of progression to cardiomyopathy in the elderly. The occurrence of a new major ECG abnormality in ChD patients predicts a higher risk of death.

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.

Clinical and electrocardiographic outcomes evaluated by telemedicine of outpatients with clinical suspicion of COVID-19 treated with chloroquine compounds in Brazil†

Aims

To evaluate clinical and electrocardiographic outcomes of patients with COVID-19, comparing those using chloroquine compounds (chloroquine) to individuals without specific treatment.

Methods

Outpatients with suspected COVID-19 in Brazil who had at least one tele-electrocardiography (ECG) recorded in a telehealth system were enrolled in two arms (Group 1: chloroquine and Group 2: without specific treatment) and one registry (Group 3: other treatments). Outcomes were assessed through follow-up calls (phone contact, days 3 and 14) and linkage to national mortality and hospitalization databases. The primary outcome was composed of: hospitalization, intensive care admission, mechanical ventilation, and all-cause death, and the ECG outcome was the occurrence of major abnormalities by the Minnesota code. Significant variables in univariable logistic regression were included in 4 models: 1-unadjusted; 2-adjusted for age and sex; 3-model 2 + cardiovascular risk factors and 4-model 3 + COVID-19 symptoms.

Results

In 303 days, 712 (10.2%) patients were allocated in group 1, 3,623 (52.1%) in group 2 and 2,622 (37.7%) in group 3; 1,969 had successful phone follow-up (G1: 260, G2: 871, and G3: 838). A late follow-up ECG was obtained for 917 (27.2%) patients [group 1: 81 (11.4%), group 2: 512 (14.1%), group 3: 334 (12.7%)]. In adjusted models, chloroquine was independently associated with greater chance of the composite clinical outcome: phone contact (model 4): OR = 3.24 (95% CI 2.31-4.54), p < 0.001. Chloroquine was also independently associated with higher mortality, assessed by phone + administrative data (model 3): OR = 1.67 (95% CI 1.20-2.28). However, chloroquine did not associate with the occurrence of major ECG abnormalities [model 3; OR = 0.80 (95% CI 0.63-1.02, p = 0.07)]. Abstracts with partial results of this work was accepted in the American Heart Association Scientific Sessions, November 2022, in Chicago, IL, USA.

Conclusion

Chloroquine was associated with a higher risk of poor outcomes in patients suspected to have COVID-19 when compared to those who received standard care. Follow-up ECGs were obtained in only 13.2% of patients and did not show any significant differences in major abnormalities amongst the three groups. In the absence of early ECG changes, other side effects, late arrhythmias or deferral of care may be hypothesized to explain the worse outcomes.

Myocardial function reclassification: Echocardiographic strain patterns in patients with chronic Chagas cardiomyopathy and intraventricular dyssynchrony

BACKGROUND

We aimed to identify, among Chronic Chagas Cardiomyopathy (CCC) patients with left ventricular dysfunction (LVD) and non-left bundle branch block (non-LBBB), subgroups with different functional and mechanical patterns of global longitudinal strain (GLS) and intraventricular dyssynchrony (IVD) at rest and after exercise stress test, and reclassify them using a new echocardiographic approach.

METHODOLOGY

In this single-center cross-sectional study, 40 patients with CCC, left ventricular ejection fraction (LVEF) ≤ 35% and non-LBBB underwent rest echocardiography and then treadmill exercise stress echocardiography with GLS and IVD analysis. The sample was divided into four groups, based on GLS and IVD significant variation between rest and exercise: GLS + IVD+ (9 patients); GLS + IVD- (9 patients); GLS-IVD+ (10 patients); GLS-IVD- (10 patients).

RESULTS

At rest, median LVEF was 28% (21.3%-33%) and GLS (-7% (-5%/-9.3%), were not different among groups. The average response of GLS was an increase of 0.74% over rest values, and the average response of IVD was a decrease of 6.9 ms. Group GLS-IVD+ presented more dyssynchrony at rest (p = 0.01). Left atrial (LA) volume (higher in GLS-IVD-) (p = 0.022) and TAPSE (higher in GLS + IVD+) (p = 0.015) were also different among groups at baseline. Of the 40 patients evaluated, 27 (67.5%) had very severe LVD (GLS < -8%). In addition, among these patients, 11 patients had contractile reserve after undergoing stress echocardiography.

CONCLUSIONS

In patients with CCC, severe LVD and non-LBBB, the evaluation of GLS and IVD between rest and exercise was able to reclassify myocardial function and to identify subgroups with contractile reserve and significant dyssynchronopathy.

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.

Incidence and Predictors of Progression to Chagas Cardiomyopathy: Long-Term Follow-Up of Trypanosoma cruzi-Seropositive Individuals

BACKGROUND

There are few contemporary cohorts of Trypanosoma cruzi-seropositive individuals, and the basic clinical epidemiology of Chagas disease is poorly understood. Herein, we report the incidence of cardiomyopathy and death associated with T. cruzi seropositivity.

METHODS

Participants were selected in blood banks at 2 Brazilian centers. Cases were defined as T. cruzi-seropositive blood donors. T. cruzi-seronegative controls were matched for age, sex, and period of donation. Patients with established Chagas cardiomyopathy were recruited from a tertiary outpatient service. Participants underwent medical examination, blood collection, ECG, and echocardiogram at enrollment (2008-2010) and at follow-up (2018-2019). The primary outcomes were all-cause mortality and development of cardiomyopathy, defined as the presence of a left ventricular ejection fraction <50% or QRS complex duration ≥120 ms, or both. To handle loss to follow-up, a sensitivity analysis was performed using inverse probability weights for selection.

RESULTS

We enrolled 499 T. cruzi-seropositive donors (age 48±10 years, 52% male), 488 T. cruzi-seronegative donors (age 49±10 years, 49% male), and 101 patients with established Chagas cardiomyopathy (age 48±8 years, 59% male). The mortality in patients with established cardiomyopathy was 80.9 deaths/1000 person-years (py) (54/101, 53%) and 15.1 deaths/1000 py (17/114, 15%) in T. cruzi-seropositive donors with cardiomyopathy at baseline. Among T. cruzi-seropositive donors without cardiomyopathy at baseline, mortality was 3.7 events/1000 py (15/385, 4%), which was no different from T. cruzi-seronegative donors with 3.6 deaths/1000 py (17/488, 3%). The incidence of cardiomyopathy in T. cruzi-seropositive donors was 13.8 (95% CI, 9.5-19.6) events/1000 py (32/262, 12%) compared with 4.6 (95% CI, 2.3-8.3) events/1000 py (11/277, 4%) in seronegative controls, with an absolute incidence difference associated with T. cruzi seropositivity of 9.2 (95% CI, 3.6-15.0) events/1000 py. T. cruzi antibody level at baseline was associated with development of cardiomyopathy (adjusted odds ratio, 1.4 [95% CI, 1.1-1.8]).

CONCLUSIONS

We present a comprehensive description of the natural history of T. cruzi seropositivity in a contemporary patient population. The results highlight the central importance of anti-T. cruzi antibody titer as a marker of Chagas disease activity and risk of progression.

Community-based entomological surveillance in three Chagas disease-endemic regions in sub-Andean Bolivia

BACKGROUND

Chagas disease is endemic throughout most of Bolivia, with prevalence rates of 25% observed in some geographic areas located mainly in the sub-Andean region.

METHODS

Community-based entomological surveillance was carried out in the sub-Andean departments of Cochabamba (municipalities of Cochabamba, Punata and Sacaba), Tarija (municipality of Tarija) and Chuquisaca (municipality of Sucre). The surveillance parameters evaluated were: (i) the proportion of cards with the presence of triatomines; (ii) the distribution of positive cards by area; and (iii) the proportion of cards with the presence of infected triatomines.

RESULTS

Of the cards returned, in 852 (3.1%) there was a mention of the presence of triatomines. The species Triatoma infestans, Triatoma sordida and Triatoma guasayana were identified in 812 (95.3%), 39 (4.6%) and 1 (0.1%), respectively. The median monthly positivity rate of the cards during 2011-2018 was higher in Punata (9.1%; IQR=3.2-15.4%). The median monthly rate was highest in 2012 (2.7%; IQR=0-5.6%). Fifty positive cards (5.8%) presented insects that were positive for trypanosomatids, mainly in Cochabamba and Punata.

CONCLUSIONS

The report of triatomines foci by inhabitants represents an effective surveillance system coordinated by a network of specialized and multidisciplinary health centers. These strategies, which should be included in the health policies of endemic countries, enable extending and deepening the dialogue among technicians, communities and their local authorities.

Where was my patient born? The Intersection of tropical medicine and migrant health

PURPOSE OF REVIEW

There is unprecedented movement of people across international borders and parasitic infections, previously restricted to endemic regions, are now encountered in nonendemic areas of the world.

RECENT FINDINGS

Migrants may import parasitic infections acquired in their countries of origin. Increasingly, clinicians in nonendemic regions are faced with patients with neglected diseases such as Chagas disease, malaria and strongyloidiasis. There are gaps in knowledge among physicians in nonendemic regions, which lead to missed opportunities for preventive strategies and early treatment. Both primary care and infectious disease physicians should have a broad knowledge of common parasitic infections to improve health outcomes and decrease healthcare disparities through early identification and treatment of disease encountered in migrants.

SUMMARY

Migrant health is still a young field in medicine; clinicians should be aware of diseases seen in migrants, and access both educational and clinical resources, including experts in tropical medicine, in order to reduce health disparities among migrants. Collaboration between primary care and infectious disease/tropical medicine experts should be strengthened.

Inhibition of calcium/calmodulin (Ca2+ /CaM)-Calcium/calmodulin-dependent protein kinase II (CaMKII) axis reduces in vitro and ex vivo arrhythmias in experimental Chagas disease

Chagasic cardiomyopathy (CCC) is one of the main causes of heart failure and sudden death in Latin America. To date, there is no available medication to prevent or reverse the onset of cardiac symptoms. CCC occurs in a scenario of disrupted calcium dynamics and enhanced oxidative stress, which combined, may favor the hyper activation of calcium/calmodulin (Ca²⁺ /CaM)-calcium/calmodulin-dependent protein kinase II (CaMKII) (Ca²⁺ /CaM-CaMKII) pathway, which is fundamental for heart physiology and it is implicated in other cardiac diseases. Here, we evaluated the association between Ca²⁺ /CaM-CaMKII in the electro-mechanical (dys)function of the heart in the early stage of chronic experimental Trypanosoma cruzi infection. We observed that in vitro and ex vivo inhibition of Ca²⁺ /CaM-CaMKII reversed the arrhythmic profile of isolated hearts and isolated left-ventricles cardiomyocytes. The benefits of the limited Ca²⁺ /CaM-CaMKII activation to cardiomyocytes' electrical properties are partially related to the restoration of Ca²⁺ dynamics in a damaged cellular environment created after T. cruzi infection. Moreover, Ca²⁺ /CaM-CaMKII inhibition prevented the onset of arrhythmic contractions on isolated heart preparations of chagasic mice and restored the responsiveness to the increase in the left-ventricle pre-load. Taken together, our data provide the first experimental evidence for the potential of targeting Ca²⁺ /CaM-CaMKII pathway as a novel therapeutic target to treat CCC.

Assessing the entomo-epidemiological situation of Chagas disease in rural communities in the state of Piauí, Brazilian semi-arid region

BACKGROUND

In northeastern Brazil, the wild nature of Trypanosoma cruzi vectors has challenged control actions. This study aims to describe the entomological and epidemiological scenario of Chagas disease in rural communities in the state of Piauí.

METHODS

A cross-sectional study (n=683 individuals/244 dwellings) was carried out to obtain serum samples, sociodemographic data and intra- and peridomestic triatomines.

RESULTS

The overall seroprevalence rate was 8.1%, with no positive tests among subjects <30 y of age. Prevalence rates reached 34.3% and 39.1% among subjects 61-75 and >75 y of age, respectively; 1474 triatomines were collected, of which 90.3% were found in peridomiciliary structures and 9.7% inside houses; 87.2% were classified as Triatoma brasiliensis. T. cruzi infection rates in insects were 0.5% by light microscopy and 0.9% by culture in NNN/LIT medium. Five cultivated isolates were submitted to molecular genotyping, three of which were identified as T. cruzi I and two as T. cruzi II.

CONCLUSIONS

Although no vector transmission currently occurs, prevalence rates are high in adults and the elderly. This disease should be targeted by primary healthcare providers. Insect surveillance and control activities should not be discontinued in an environment favourable to the perpetuation of house colonization by triatomines.

Deriving a parsimonious cardiac endpoint for use in epidemiological studies of Chagas disease: results from the Retrovirus Epidemiology Donor Study-II (REDS-II) cohort

Chagas cardiomyopathy (ChCM) is a severe consequence of Trypanosoma cruzi infection and has a range of electrocardiographic (ECG) and echocardiographic (ECHO) manifestations. There is a need for a standard and parsimonious research cardiac end point that does not rely on expert panel adjudication, and it is not intended to change the ChCM definition. We use data from the REDS-II cohort to propose a simplified cardiac endpoint. A total of 499 T. cruzi-seropositive blood donors were included. All participants underwent a 12-lead ECG, echocardiogram and clinical examination, and those with abnormal findings were reviewed by a panel of cardiologists who classified cases as having Chagas cardiomyopathy or not. We created an exhaustive set of ECG and ECHO finding combinations and compared these with the panel's classification. We selected the simplest combination that most accurately reproduced the panel's results. Individual ECG and ECHO variables had low sensitivity for panel-defined cardiomyopathy. The best performing combination was right bundle branch block and/or ECHO evidence of left ventricular hypocontractility. This combination had 98% specificity and 85% sensitivity for panel-defined ChCM. It was not possible to improve the overall accuracy by addition of any other ECG or ECHO variable. Substituting right bundle branch block for the more inclusive finding of QRS interval > 120 ms produced similar results. The combination of prolonged QRS interval and/or left ventricular hypocontractility closely reproduced the REDS-II expert panel classification of Chagas ChCM. In conclusion, the simple and reproducible research endpoint proposed here captures most of the spectrum of cardiac abnormalities in Chagas disease.

The Vectorcardiogram and the Main Dromotropic Disturbances

Until the mid-1980s, it was believed that the vectorcardiogram (VCG) presented a greater specificity, sensitivity and accuracy in comparison to the 12-lead electrocardiogram (ECG), in the cardiology diagnosis. Currently, the VCG still is superior to the ECG in specific situations, such as in the evaluation of myocardial infarctions when associated with intraventricular conduction disturbances, in the identification and location of accessory pathways in ventricular preexcitation, in the differential diagnosis of patterns varying from normal of electrical axis deviation, in the evaluation of particular aspects of Brugada syndrome, Brugada phenocopies, concealed form of arrhythmogenic right ventricular cardiomyopathy and zonal or fascicular blocks of the right bundle branch on right ventricular free wall.VCG allows us to analyze the presence of left septal fascicular block more accurately than ECG and in the diagnosis of the interatrial blocks and severity of some chambers enlargements. The three-dimensional spatial orientation of both the atrial and the ventricular activity provides a far more complete observation tool than the linear ECG. We believe that the ECG/VCG binomial simultaneously obtained by the technique called electro-vectorcardiography (ECG/VCG) brought a significant gain for the differential diagnosis of several pathologies. Finally, in the field of education and research, VCG provided a better and more rational tridimensional insight into the electrical phenomena that occurs spatially, and represented an important impact on the progress of electrocardiography.

Rare Pathogenic Variants in Mitochondrial and Inflammation-Associated Genes May Lead to Inflammatory Cardiomyopathy in Chagas Disease

Abstract

Cardiomyopathies are an important cause of heart failure and sudden cardiac death. Little is known about the role of rare genetic variants in inflammatory cardiomyopathy. Chronic Chagas disease cardiomyopathy (CCC) is an inflammatory cardiomyopathy prevalent in Latin America, developing in 30% of the 6 million patients chronically infected by the protozoan Trypanosoma cruzi, while 60% remain free of heart disease (asymptomatic (ASY)). The cytokine interferon-γ and mitochondrial dysfunction are known to play a major pathogenetic role. Chagas disease provides a unique model to probe for genetic variants involved in inflammatory cardiomyopathy.

Methods

We used whole exome sequencing to study nuclear families containing multiple cases of Chagas disease. We searched for rare pathogenic variants shared by all family members with CCC but absent in infected ASY siblings and in unrelated ASY.

Results

We identified heterozygous, pathogenic variants linked to CCC in all tested families on 22 distinct genes, from which 20 were mitochondrial or inflammation-related – most of the latter involved in proinflammatory cytokine production. Significantly, incubation with IFN-γ on a human cardiomyocyte line treated with an inhibitor of dihydroorotate dehydrogenase brequinar (enzyme showing a loss-of-function variant in one family) markedly reduced mitochondrial membrane potential (ΔψM), indicating mitochondrial dysfunction.

Conclusion

Mitochondrial dysfunction and inflammation may be genetically determined in CCC, driven by rare genetic variants. We hypothesize that CCC-linked genetic variants increase mitochondrial susceptibility to IFN-γ-induced damage in the myocardium, leading to the cardiomyopathy phenotype in Chagas disease. This mechanism may also be operative in other inflammatory cardiomyopathies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01000-y.

Neglected cardiovascular diseases and their significance in the Global North

Due to increasing global migration, the spectrum of cardiovascular disease (CVD) is changing in developed countries. Up to 3% of migrants arriving in Europe have underlying CVD. Despite their high global prevalence, conditions such as rheumatic heart disease, Chagas disease, endomyocardial fibrosis, tuberculous pericarditis, peripartum cardiomyopathy, and pulmonary hypertension are often under-recognized, and, as a result, neglected in industrialized countries. Many of these conditions, and their causes, are often unfamiliar to the health-care providers in host countries. In this review, we summarize the epidemiology, etiology, clinical presentation, diagnostic work-up, and management of neglected CVDs that have an increasing prevalence in the Global North.

Declining antibody levels to Trypanosoma cruzi correlate with polymerase chain reaction positivity and electrocardiographic changes in a retrospective cohort of untreated Brazilian blood donors

Background

Although infection with Trypanosoma cruzi is thought to be lifelong, less than half of those infected develop cardiomyopathy, suggesting greater parasite control or even clearance. Antibody levels appear to correlate with T. cruzi (antigen) load. We test the association between a downwards antibody trajectory, PCR positivity and ECG alterations in untreated individuals with Chagas disease.

Methodology/Principal findings

This is a retrospective cohort of T. cruzi seropositive blood donors. Paired blood samples (index donation and follow-up) were tested using the VITROS Immunodiagnostic Products Anti-T.cruzi (Chagas) assay (Ortho Clinical Diagnostics, Raritan NJ) and PCR performed on the follow-up sample. A 12-lead resting ECG was performed. Significant antibody decline was defined as a reduction of > 1 signal-to-cutoff (S/CO) unit on the VITROS assay. Follow-up S/CO of < 4 was defined as borderline/low. 276 untreated seropositive blood donors were included. The median (IQR) follow-up was 12.7 years (8.5–16.9). 56 (22.1%) subjects had a significant antibody decline and 35 (12.7%) had a low/borderline follow-up result. PCR positivity was lower in the falling (26.8% vs 52.8%, p = 0.001) and low/borderline (17.1% vs 51.9%, p < 0.001) antibody groups, as was the rate of ECG abnormalities. Falling and low/borderline antibody groups were predominantly composed of individuals with negative PCR and normal ECG findings: 64% and 71%, respectively.

Conclusions/Significance

Low and falling antibody levels define a phenotype of possible spontaneous parasite clearance.

Infection with the single-celled parasite Trypanosoma cruzi (Chagas disease) is thought to be lifelong. However, only a third of infected people develop Chagas cardiomyopathy–the main disease manifestation. This may reflect the different extent to which individuals control the parasite, with some potentially clearing it entirely. In chronically infected immunocompetent patients, a marker of parasite burden is the quantity of antibody against T. cruzi in the blood: more parasite, more immune stimulation, more antibody. In this study we show how antibody levels change over many years in a cohort of untreated patients with Chagas disease. We find that among individuals with falling or low/borderline antibody levels there was a lower rate of parasite detection in the blood and a lower rate of cardiomyopathy. 60% of subjects with falling antibody levels had no evidence of active disease, twice as many as among patients with other antibody trajectories (stable or rising). Our findings support an account of the natural history of Chagas disease in which a proportion of those infected achieve a greater control of the parasite, with some individuals potentially clearing it completely.

Chagas cardiomyopathy and heart failure: From epidemiology to treatment

Chagas disease is among the neglected tropical diseases recognized by the World Health Organization that have received insufficient attention from governments and health agencies. Chagas disease is endemic in 21 Latin America regions. Due to globalization and increased migration, it has crossed borders and reached other regions including North America and Europe. The clinical presentation of the disease is highly variable, from general symptoms to severe cardiac involvement that can culminate in heart failure. Chagas heart disease is multifactorial, and can include dilated cardiomyopathy, thromboembolic phenomena, and arrhythmias that may lead to sudden death. Diagnosis is by methods such as enzyme-linked immunosorbent assay (ELISA) and the degree of cardiac involvement should be investigated with complementary exams including ECG, chest radiography and electrophysiological study. There have been insufficient studies on which to base specific treatment for heart failure due to Chagas disease. Treatment should therefore be derived from guidelines for heart failure that are not specific for this disease. Heart transplantation is a viable option with satisfactory success rates that has improved survival.

Impact of the social context on the prognosis of Chagas disease patients: Multilevel analysis of a Brazilian cohort

The present study aims to investigate how the social context contributes to the prognosis of Chagas disease (CD). This is a multilevel study that considered individual and contextual data. Individual data came from a Brazilian cohort study that followed 1,637 patients who lived in 21 municipalities to which CD is endemic, over two years. Contextual data were collected from official Brazilian government databases. The dependent variable was the occurrence of cardiovascular events in CD during the two-year follow-up, defined from the grouping of three possible combined events: death, development of atrial fibrillation, or pacemaker implantation. Analysis was performed using multilevel binary logistic regression. Among the individuals evaluated, 205 (12.5%) manifested cardiovascular events in CD during two years of follow-up. Individuals living in municipalities with a larger rural population had protection for these events (OR = 0.5; 95% CI = 0.4-0.7), while those residing in municipalities with fewer physicians per thousand inhabitants (OR = 1.6; 95% CI = 1.2-2.5) and those living in municipalities with lower Primary Health Care (PHC) coverage (OR = 1.4; 95% CI = 1.1-2.1) had higher chances of experiencing cardiovascular events. Among the individual variables, the probability of experiencing cardiovascular events was higher for individuals aged over 60 years (OR = 1.4; 95% CI = 1.01-2.2), with no stable relationship (OR = 1.4; 95% CI = 0.98-2.1), without previous treatment with Benznidazole (OR = 1.5; 95% CI = 0.98-2.9), with functional class limitation (OR = 2.0; 95% CI = 1.4-2.9), with a QRS complex duration longer than 120 ms (OR = 1.5; 95% CI = 1.1-2.3), and in individuals with high NT-proBNP levels (OR = 6.4; 95% CI = 4.3-9.6). CONCLUSION: The present study showed that the occurrence of cardiovascular events in individuals with CD is determined by individual conditions that express the severity of cardiovascular involvement. However, these individual characteristics are not isolated protagonists of this outcome, and the context in which individuals live, are also determining factors for a worse clinical prognosis.

CXCL9 and CXCL10 display an age-dependent profile in Chagas patients: a cohort study of aging in Bambui, Brazil

Background

Chagas disease is endemic in Latin America and still represents an important public health problem in the region. Chronic cardiomyopathy is the most significant chronic form due to its association with morbidity and mortality. The last decade has seen increasing evidence that inflammatory cytokines and chemokines are responsible for the generation of inflammatory infiltrate and tissue damage, with chronic chagasic cardiomyopathy patients presenting a pro-inflammatory immune response. Although studies have evaluated the role of chemokines in experimental T. cruzi infection, few have addressed their systemic profile, especially for human infection and in aging populations. The present work aimed to use the data from a large population based study of older adults, conducted in an endemic area for Chagas disease, to examine the association between serum levels of cytokines and chemokines, T. cruzi infection and electrocardiogram (ECG) abnormality.

Methods

The present work evaluated serum levels of CCL2, CXCL9, CXCL10, CCL5, CXCL8, IL-1β, IL-6, TNF, IL-12 and IL-10 by Flow Cytometric Bead Array assay (CBA) and the results expressed in pg/ml. The baseline survey started in January 1st 1997, with 1284 participants of an aged population-based cohort. Participants signed an informed consent at baseline and at each subsequent visit and authorized death certificate and medical records verification.

Results

Our results demonstrated that Chagas disease patients had higher serum levels of CXCL9, CXCL10 and IL-1β and lower serum levels of CCL5 than non-infected subjects. Moreover, our data demonstrated that CXCL9 and CXCL10 increased in an age-dependent profile in Chagas disease patients.

Conclusion

Together, this study provided evidences that serum biomarkers increase along the age continuum and may have potential implications for establishing clinical management protocols and therapeutic intervention in Chagas disease patients.

Risk Score for Predicting 2-Year Mortality in Patients With Chagas Cardiomyopathy From Endemic Areas: SaMi-Trop Cohort Study

Background

Risk stratification of Chagas disease patients in the limited‐resource setting would be helpful in crafting management strategies. We developed a score to predict 2‐year mortality in patients with Chagas cardiomyopathy from remote endemic areas.

Methods and Results

This study enrolled 1551 patients with Chagas cardiomyopathy from Minas Gerais State, Brazil, from the SaMi‐Trop cohort (The São Paulo‐Minas Gerais Tropical Medicine Research Center). Clinical evaluation, ECG, and NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) were performed. A Cox proportional hazards model was used to develop a prediction model based on the key predictors. The end point was all‐cause mortality. The patients were classified into 3 risk categories at baseline (low, <2%; intermediate, ≥2% to 10%; high, ≥10%). External validation was performed by applying the score to an independent population with Chagas disease. After 2 years of follow‐up, 110 patients died, with an overall mortality rate of 3.505 deaths per 100 person‐years. Based on the nomogram, the independent predictors of mortality were assigned points: age (10 points per decade), New York Heart Association functional class higher than I (15 points), heart rate ≥80 beats/min (20 points), QRS duration ≥150 ms (15 points), and abnormal NT‐proBNP adjusted by age (55 points). The observed mortality rates in the low‐, intermediate‐, and high‐risk groups were 0%, 3.6%, and 32.7%, respectively, in the derivation cohort and 3.2%, 8.7%, and 19.1%, respectively, in the validation cohort. The discrimination of the score was good in the development cohort (C statistic: 0.82), and validation cohort (C statistic: 0.71).

Conclusions

In a large population of patients with Chagas cardiomyopathy, a combination of risk factors accurately predicted early mortality. This helpful simple score could be used in remote areas with limited technological resources.

Evaluation of mortality in bundle branch block patients from an electronic cohort: Clinical Outcomes in Digital Electrocardiography (CODE) study

BACKGROUND

Left bundle branch block is recognized as a marker of higher risk of death, but the prognostic value of the right bundle branch block in the general population is still controversial. Our aim is to evaluate the risk of overall and cardiovascular mortality in patients with right (RBBB) and left bundle branch block (LBBB) in a large electronic cohort of Brazilian patients.

METHODS

This observational retrospective study was developed with the database of digital ECGs from Telehealth Network of Minas Gerais, Brazil (TNMG). All ECGs performed from 2010 to 2017 in primary care patients over 16 years old were assessed. The electronic cohort was obtained by linking data from ECG exams (name, sex, date of birth, city of residence) and those from national mortality information system, using standard probabilistic linkage methods (FRIL: Fine-grained record linkage software, v.2.1.5, Atlanta, GA). Only the first ECG of each patient was considered. Clinical data were self-reported, and ECGs were interpreted manually by cardiologists and automatically by the Glasgow University Interpreter software. Hazard ratio (HR) for mortality was estimated using Cox regression.

RESULTS

From a dataset of 1,773,689 patients, 1,558,421 primary care patients over 16 years old underwent a valid ECG recording during 2010 to 2017. We excluded 17,359 patients that didn't have a valid QRS measure from the Glasgow program and 11,091 patients from the control group that had QRS equal or above 120 ms and were not RBBB or LBBB. Therefore, 1,529,971 were included (median age 52 [Q1:38; Q3:65] years; 40.2% were male). In a mean follow-up of 3.7 years, the overall mortality rate was 3.34%. RBBB was more frequent (2.42%) than LBBB (1.32%). In multivariate analysis, adjusting for sex, age and comorbidities, both patients with RBBB (HR 1.32; CI 95% 1.27-1.37) and LBBB (HR 1.69; CI 95% 1.62-1.76) had higher risk of overall mortality. Women with RBBB had an increased risk of all-cause death compared to men (p < 0.001). Cardiovascular mortality was higher in patients with LBBB (HR 1.77; CI 95% 1.55-2.01), but not for RBBB.

CONCLUSIONS

Patients with RBBB and LBBB had higher risk of overall mortality. Women with RBBB had more risk of all-cause death than men. LBBB was associated with higher risk of cardiovascular mortality.

Subclinical Thyroid Dysfunction was not Associated with Cardiac Arrhythmias in a Cross-Sectional Analysis of the ELSA-Brasil Study

Background

The association of subclinical thyroid dysfunction (STD) with cardiac arrhythmias remains controversial, particularly in the non-elderly population.

Objective

To investigate whether STD was associated with cardiac arrhythmias in a cohort of middle-aged and older adults.

Methods

Baseline data of the Longitudinal Study of Adult Health, ELSA-Brasil (35-74 years) were collected from 2008 to 2010. After exclusion of clinical hypothyroidism and hyperthyroidism, participants were categorized as euthyroidism (TSH = 0.4-4.0 µU/mL), subclinical hypothyroidism (TSH > 4.0 µU/mL; FT4 = 0.8-1.9 ng/dL), and subclinical hyperthyroidism (TSH < 0.4 µU/mL; FT4 = 0.8-1.9 ng/dL). The prevalence rates of tachycardia (HR > 100) and bradycardia (HR < 60), atrial fibrillation/flutter, conduction disorders, extrasystoles, low QRS voltage, prolonged QT intervals, and persistent supraventricular rhythms were compared between groups after adjusting for age, sex, comorbidities, lifestyle, body mass index and medications.

Results

The HR data of 13,341 participants (52% female; median age, 51 years) and the electrocardiogram readings of 11,795 were analyzed; 698 participants (5.23%) were classified as subclinical hypothyroidism, 193 (1.45%) as subclinical hyperthyroidism, and 12,450 (93.32%) as euthyroidism. The prevalence of rhythm and conduction disorders was similar, as were HR medians, even in the subgroups with TSH < 0.01 UI/mL or > 10.0 UI/mL or in older adults. Conduction disorders were less prevalent in older adults with subclinical hypothyroidism (adjusted OR = 0.44; 95% CI 0.24 to 0.80).

Conclusion

In this large, multicenter and cross-sectional study, STD was not associated with cardiac arrhythmias, but a longitudinal assessment is necessary.

Cardiac Involvement by Yellow Fever(from the PROVAR+ Study)

Incidence of Yellow Fever (YF) has increased in Brazil, and cardiac findings such as bradyarrhythmias and conduction abnormalities have been described. We aimed to perform a comprehensive cardiac evaluation of patients with YF, and to assess the association between cardiac involvement and disease severity. Patients hospitalized with YF from February to March 2018 underwent clinical and laboratory evaluation, focused bedside echocardiography (GE Vivid IQ), electrocardiogram and, in case of alterations, 24-hours Holter. Patients were divided into 2 groups according to YF severity. Five patients underwent magnetic resonance imaging and 3 had necropsy. Seventy patients had confirmed YF, 69% with severe form. Mean age was 48 ± 14 years, 63 (90%) were males and 5 (7%) died. Significant electrocardiogram abnormalities were present in 52% of patients with mild/moderate form of YF (G1) and 77% of those with severe form (G2), p = 0.046. Sinus bradycardia was observed in 24% (N = 17): G1 23% versus G2 25%, p = 0.67. Among 32 patients who underwent Holter, 14 (44%) had mean HR <60 beats per minute, being 8 from G2. Echocardiogram revealed left ventricular dysfunction in 4 (6%) patients, from G2. Left ventricular wall thickening with a hyper-refringent myocardial texture suggesting infiltration was observed in 17 patients (G1 18% vs G2 27%, p = 0.55). One magnetic resonance (G2) was suggestive of myocarditis, and one necropsy revealed areas of myocardial necrosis and acute myocarditis. In conclusion, cardiac involvement was observed in patients with YF, most commonly bradycardia and myocardial hyper-refringent texture suggestive of infiltration.

Beneficial effects of benznidazole in Chagas disease: NIH SaMi-Trop cohort study

BACKGROUND

The effectiveness of anti-parasite treatment with benznidazole in the chronic Chagas disease (ChD) remains uncertain. We evaluated, using data from the NIH-sponsored SaMi-Trop prospective cohort study, if previous treatment with benznidazole is associated with lower mortality, less advanced cardiac disease and lower parasitemia in patients with chronic ChD.

METHODS

The study enrolled 1,959 ChD patients and abnormal electrocardiogram (ECG) from in 21 remote towns in Brazil. A total of 1,813 patients were evaluated at baseline and after two years of follow-up. Those who received at least one course of benznidazole were classified as treated group (TrG = 493) and those who were never treated as control group (CG = 1,320). The primary outcome was death after two-year follow-up; the secondary outcomes were presence at the baseline of major ChD-associated ECG abnormalities, NT-ProBNP levels suggestive of heart failure, and PCR positivity.

RESULTS

Mortality after two years was 6.3%; it was lower in the TrG (2.8%) than the CG (7.6%); adjusted OR: 0.37 (95%CI: 0.21;0.63). The ECG abnormalities typical for ChD and high age-adjusted NT-ProBNP levels suggestive of heart failure were lower in the TrG than the CG, OR: 0.35 [CI: 0.23;0.53]. The TrG had significantly lower rates of PCR positivity, OR: 0.35 [CI: 0.27;0.45].

CONCLUSION

Patients previously treated with benznidazole had significantly reduced parasitemia, a lower prevalence of markers of severe cardiomyopathy, and lower mortality after two years of follow-up. If used in the early phases, benznidazole treatment may improve clinical and parasitological outcomes in patients with chronic ChD.

TRIAL REGISTRATION

ClinicalTrials.gov, Trial registration: NCT02646943.

Association between typical electrocardiographic abnormalities and NT-proBNP elevation in a large cohort of patients with Chagas disease from endemic area

Chagas cardiomyopathy is the most harmful complication of Chagas disease. The electrocardiogram is a well-studied exam and has been considered an important tool for detection and evaluation of Chagas cardiomyopathy since the first years of its description. Many of its abnormalities have been described as associated with a worse prognosis. Serum BNP levels were described as inversely related to the left ventricular ejection fraction and as an independent predictor of death. It was not reported how electrocardiographic alterations correlate to NT-proBNP and its analog. The present study aims to describe the baseline electrocardiograms of a large cohort of patients with Chagas disease from endemic area and to establish an association between the number of electrocardiogram alterations and high levels of NT-ProBNP in Chagas disease patients. This study selected 1959 Chagas disease patients in 21 municipalities within a limited region in the northern part of the State of Minas Gerais (Brazil), 1084 of them had Chagas cardiomyopathy. NT-proBNP levels were suggestive of heart failure in 11.7% of this population. One or more electrocardiographic alterations have an Odds Ratio of 9.12 (CI 95% 5.62-14.80) to have NT-proBNP elevation. Considering the association between the number of 1, 2, and 3 or more alterations in electrocardiogram and NT-proBNP elevation, the ORs were 7.11 (CI 95% 4.33-11.67); 16.04 (CI 95% 9.27-27.77) and 47.82 (CI 95% 17.98-127.20), respectively. The presence and the number of typical electrocardiographic alterations of Chagas disease are independently associated with the severity of the cardiomyopathy.

Electrocardiogram in Chagas disease

Since the initial descriptions of Chagas cardiomyopathy (ChCM), the electrocardiography has played a key role in patient evaluations. The diagnostic criterion of chronic ChCM is the presence of characteristic electrocardiographic (ECG) abnormalities in seropositive individuals, regardless of the presence of symptoms. However, these ECG abnormalities are rarely specific to ChCM and, particularly among the elderly, can be caused by other simultaneous cardiomyopathies. ECG abnormalities can predict the occurrence of heart failure, stroke, and even death. Nevertheless, most prognostic studies have included Chagas disease (ChD) populations and, not exclusively, ChCM. Thus, more studies are required to evaluate the efficacy of ECG in predicting reliable prognoses in established chronic ChCM. This review exclusively discusses the role of the 12-lead ECG in the clinical evaluation of chronic ChD.

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.

Value of the Electrocardiographic (P Wave, T Wave, QRS) Axis as a Predictor of Mortality in 14 Years in a Population With a High Prevalence of Chagas Disease from the Bambuí Cohort Study of Aging

We sought to investigate the prognostic value of the electrocardiogram (ECG) electrical axes (P wave, T wave and QRS) as predictors of mortality in the 14-year follow-up of the prospective cohort of all residents ≥60 years living in the southeastern Brazilian city of Bambuí, a population with high prevalence of Chagas disease (ChD). Baseline ECG axes were automatically measured with normal values defined as follows: P-wave axis 0° to 75°, QRS axis -30° to 90°, and T axis 15° to 75°. Participants underwent annual follow-up visits and death was verified using death certificates. Cox proportional hazards regression was used to assess the prognostic value of ECG axes for all-cause mortality, after adjustment for potential confounders. From 1,742 qualifying residents, 1,462 were enrolled, of whom 557 (38.1%) had ChD. Mortality rate was 51.9%. In multivariable adjusted models, abnormal P-wave axis was associated with a 48% (hazard ratio [HR] = 1.48 [95% confidence interval (CI) 1.16-1.88]) increased mortality risk in patients with ChD and 43% (HR = 1.43 [CI 1.13-1.81]) in patients without ChD. Abnormal QRS axis was associated with a 34% (HR = 1.34 [CI 1.04-1.73]) increased mortality risk in patients with ChD, but not in individuals without ChD. Similarly, in the ChD group, abnormal T-wave axis was associated with a 35% (HR = 1.35 [CI 1.07-1.71]) increased mortality, but not in patients without ChD. In conclusion, abnormal P-wave, QRS, and T-wave axes were associated with increased all-cause mortality in patients with ChD. Abnormal P-wave axis was associated with mortality also among those without ChD, being the strongest predictor among ECG variables.

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.