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

Enhancing risk assessment in Chagas cardiomyopathy: Electrophysiology study stratified by Rassi score

BACKGROUND

Chagas cardiomyopathy (CCM) is increasingly prevalent in developed countries due to migration from endemic areas. Accurate risk stratification is crucial due to the variable clinical course of CCM.

OBJECTIVE

To analyze the association between Rassi score progression and electrophysiology study (EPS) changes in CCM patients.

METHODS

This prospective, observational cohort study involved CCM patients from two tertiary hospitals. Patients were classified as low, intermediate, or high risk based on the Rassi score. Data collected included demographics, clinical history, and diagnostic tests. EPS assessed AH, HH, and HV intervals, and inducibility of ventricular arrhythmias. Follow-ups were at 30 days and six-month intervals, with individualized discussions for cardiac implantable electric devices (CIED) based on EPS results.

RESULTS

Of 67 screened CCM patients, 59 underwent EPS. The mean Rassi score was 8.7 ± 4.5 points, with 33.8 % low, 38.9 % intermediate, and 27.1 % high risk. EPS abnormalities were found in 57.6 % of patients, mainly VT/VF (52.5 %). Most induced ventricular arrhythmias were monomorphic VT (80.7 %). A significant association was found between Rassi score risk classification and EPS changes (OR = 1.88 95 %CI: 1.15-3.06 p = 0.02). Higher Rassi scores correlated with VT presence on EPS (p = 0.0036). Syncope/pre-syncope had an OR 2.45 95 %CI:1.21-4.94; p = 0.012, independent of Rassi risk. Decreased ejection fraction was linked to EPS changes (p = 0.04).

CONCLUSION

EPS changes among CCM was associated with progression of the Rassi score, indicating its utility as a stratification tool. Factors such as the presence of syncope/pre-syncope, decreased LVEF and wall motion abnormalities emerged as independent predictors within Rassi scores for changes in EPS.

Tackling the challenges of human Chagas disease: A comprehensive review of treatment strategies in the chronic phase and emerging therapeutic approaches

Chagas disease (CD), caused by the flagellated protozoan Trypanosoma cruzi (T. cruzi), affects approximately 7 million people worldwide and is endemic in Latin America, especially among socioeconomically disadvantaged populations. Since the 1960s, only two drugs have been commercially available for treating this illness: nifurtimox (NFX) and benznidazole (BZN). Although these drugs are effective in the acute phase (AP) of the disease, in which parasitemia is usually high, their cure rates in the chronic phase (CP) are low and often associated with several side effects. The CP is characterized by a subpatent parasitaemia and absence of clinical symptoms in the great majority of infected individuals. However, at least 30 % of the individuals will develop potentially lethal symptomatic forms, including cardiac and digestive manifestations. For such reason, in the CP the treatment is usually symptomatic and typically focuses on managing complications such as arrhythmias, heart failure, or digestive problems. Therefore, the need for new drugs or therapeutic approaches using BZN or NFX is extremely urgent. This review presents the main clinical trials, especially in the CP, which involve BZN and NFX in different treatment regimens. Additionally, other therapies using combinations of these drugs with other substances such as allopurinol, itraconazole, ravuconazole, ketoconazole, posaconazole and amiodarone are also reported. The importance of early diagnosis, especially in pediatric patients, is also discussed, emphasizing the need to identify the disease in its early stages to improve the chances of successful treatment.

Arrhythmogenic Manifestations of Chagas Disease: Perspectives From the Bench to Bedside

Chagas cardiomyopathy caused by infection with the intracellular parasite Trypanosoma cruzi is the most common and severe expression of human Chagas disease. Heart failure, systemic and pulmonary thromboembolism, arrhythmia, and sudden cardiac death are the principal clinical manifestations of Chagas cardiomyopathy. Ventricular arrhythmias contribute significantly to morbidity and mortality and are the major cause of sudden cardiac death. Significant gaps still exist in the understanding of the pathogenesis mechanisms underlying the arrhythmogenic manifestations of Chagas cardiomyopathy. This article will review the data from experimental studies and translate those findings to draw hypotheses about clinical observations. Human- and animal-based studies at molecular, cellular, tissue, and organ levels suggest 5 main pillars of remodeling caused by the interaction of host and parasite: immunologic, electrical, autonomic, microvascular, and contractile. Integrating these 5 remodeling processes will bring insights into the current knowledge in the field, highlighting some key features for future management of this arrhythmogenic disease.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Correlation of TcII discrete typing units with severe chronic Chagas cardiomyopathy in patients from various Brazilian geographic regions

BACKGROUND

Chagas disease (ChD) is caused by Trypanosoma cruzi. The genetic structure of the species is divided into seven distinct genetic groups, TcI to TcVI, and Tcbat, which have shown differences in terms of geographic distribution, biological properties, and susceptibility to drugs. However, the association between genetic variability and clinical forms of ChD has not yet been fully elucidated. The predominance of TcII and TcVI discrete typing units (DTUs) (genetic groups) is known to occur in several Brazilian regions and is associated with both the domestic and the wild cycles of ChD. Thus, this study aimed to verify the genotypes of the parasites present in 330 patients with chronic Chagas cardiomyopathy (CCC) from different Brazilian states attended at the Clinical Hospital of the Ribeirão Preto Medical School and to assess the existence of a correlation between the clinical forms with the main cardiovascular risk factors and the genetics of the parasite.

METHODOLOGY PRINCIPAL FINDINGS

All patients with CCC were clinically evaluated through anamnesis, physical examination, biochemical tests, 12-lead electrocardiogram, echocardiogram and chest X-ray. Peripheral blood (5 mL) was collected in guanidine/ethylenediaminetetraacetic acid from each patient for DNA extraction and real-time polymerase chain reaction (PCR) for Chagas disease and genotyping of the parasite in the 7 DTUs. Parasite genotyping was performed using conventional multilocus PCR. Samples of only 175 patients were positive after amplification of the specific genes contained in the T. cruzi genotyping criteria. TcII (64/175), TcVI (9/175), and TcI (3/175) DTUs were predominant, followed by TcII/TcV/TcVI (74/175), and TcII/TcVI (23/175). The TcIII and TcIV DTU´s was detected in only one sample of CCC patients.

CONCLUSIONS/SIGNIFICANCE

Our data corroborate previous findings, indicating the predominance of the TcII genotype in patients with CCC of Brazilian origin. Moreover, this study pioneered disclosing a direct correlation between the TcII DTU and severe CCC.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Two-dimensional strain derived parameters provide independent predictors of progression to Chagas cardiomyopathy and mortality in patients with Chagas disease

Background

Patients with chronic Chagas disease (CD) cardiomyopathy have a high mortality. We evaluated if two-dimensional (2D) strain (ε) parameters provide independent predictors of progression to CD cardiomyopathy and all-cause mortality.

Methods

A total of 408 patients with chronic CD (58.6% women; 53 ± 11 years; clinical forms: indeterminate 34.1%, cardiac 57.6%, digestive 1.2%, cardiodigestive 7.1%) were consecutively included in this single-center prospective longitudinal study. Echocardiographic evaluation included left atrial and left ventricular (LV) function on ε analyses. Primary end-point was a composite of all-cause mortality or heart transplant. Secondary end-point was CD progression defined as the occurrence of changes typical of CD in electrocardiogram, sustained ventricular tachycardia, wall motion abnormalities, or heart failure among patients with the indeterminate form at baseline. Multivariable Cox-proportional-hazards regression analyses were performed to test if 2D ε parameters were associated with the studied end-points. P values < 0.05 were considered significant.

Results

The primary end-point occurred in 91 patients after a follow-up of 6.5 ± 2.7 years. CD progression occurred in 26 out of 144 patients without cardiac form at baseline (2.88 cases/100 patient-years). Peak LV circumferential (HR 1.09, 95% CI 1.01–1.18, P = .02) and radial (HR 0.97, 95% CI 0.95–0.99, P = .007) ε, and LV torsion (HR 0.51, 95% CI 0.35–0.74, P = .0004) were independent predictors of the primary end-point. Peak LV radial ε (HR 0.96, 95% CI 0.93–0.99, P = .03) was an independent predictor of CD progression.

Conclusions

Therefore, 2D ε derived parameters can be useful for CD progression and mortality prediction.

Parasitic Load Correlates With Left Ventricular Dysfunction in Patients With Chronic Chagas Cardiomyopathy

Background: Chronic Chagas disease (CChD), one of the infectious parasitic diseases with the greatest social and economic impact upon a large part of the American continent, has distinct clinical manifestations in humans (cardiac, digestive, or mixed clinical forms). The mechanisms underlying the development of the most common and ominous clinical form, the chronic Chagas cardiomyopathy (CCC) have not been completely elucidated, despite the fact that a high intensity of parasite persistence in the myocardium is deemed responsible for an untoward evolution of the disease. The present study aimed to assess the parasite load CCC and its relation to left ventricular ejection fraction (LVEF), a definite prognostic marker in patients with CCC.

Methods: Patients with CCC were clinically evaluated using 12-lead-electrocardiogram, echocardiogram, chest X-ray. Peripheral blood sampling (5 ml of venous blood in guanidine/EDTA) was collected from each patient for subsequent DNA extraction and the quantification of the parasite load using real-time PCR.

Results: One-hundred and eighty-one patients with CCC were evaluated. A total of 140 (77.3%) had preserved left ventricular ejection fraction (of ≥40%), and 41 individuals had LV dysfunction (LVEF of <40%). A wide variation in parasite load was observed with a, mean of 1.3460 ± 2.0593 (0.01 to 12.3830) par. Eq./mL. The mean ± SD of the parasite load was 0.6768 ± 0.9874 par. Eq./mL and 3.6312 ± 2.9414 par. Eq./mL in the patients with LVEF ≥ 40% and <40%, respectively.

Conclusion: The blood parasite load is highly variable and seems to be directly related to the reduction of LVEF, an important prognostic factor in CCC patients.

Prospective study of ventricular function and myocardial deformation related to survival in acute Chagas disease: an experimental animal model

Chagas disease (CD) has been changing from an endemic Latino-American disease to a condition found outside endemic regions, due to migratory movements. Although often subclinical, its acute phase can be lethal. This study aimed to assess survival during the acute phase of CD and its relationship with ventricular function in an experimental model. To this end, 30 Syrian hamsters were inoculated with Trypanosoma cruzi (IG) and other 15 animals received saline solution (CG). Groups were monitored daily and submitted to echocardiography in two moments: before the challenge and 15 days post-infection. Left ventricular ejection fraction (LVEF) and global longitudinal myocardial strain (GLS) of the LV were measured. The IG was divided into groups of animals with and without clinical signs of disease. ANOVA for mixed models was used to compare ventricular function parameters. Survival analysis was studied using Kaplan-Meier curves and the log-rank test. The follow-up lasted 60 days. LVEF in IG was reduced through time (53.80 to 43.55%) compared to CG (57.86 to 59.73%) (p=0.002). There was also a reduction of GLS (-18.97% to -12.44%) in the IG compared to CG (p=0.012). Twelve animals from IG died compared to one animal from CG. Eleven out of the 12 animals from the IG group died before presenting with clinical signs of infection. Survival was reduced in the IG compared to CG over time (p=0.02). The reduced survival during the acute phase of this experimental model of Chagas disease was related to the significant reduction of LV function. The mortality rate in the IG was higher in the group presenting with clinical signs of infection.

A Rapid Review on the Efficacy and Safety of Pharmacological Treatments for Chagas Disease

Chagas disease remains a neglected tropical disease, causing significant burden in the Americas and countries that receive immigrants from endemic nations. Current pharmaceutical treatments are suboptimal, not only varying drastically in efficacy, depending on the stage of disease, but also presenting significant risk of adverse events. The objective of this review is to provide a timely update on the efficacy and safety of current trypanocidals. Eligible studies published from January 2015 to December 2020 were retrieved by one reviewer from six electronic databases. Ana-lysis was done with review management software and risk of bias was assessed using tools appropriate for the type of study (i.e., experimental or observational). Thirteen studies (10 observational and three RCTs) were included in the analysis. All 13 studies tested Benznidazole (BNZ) or Nifurtimox (NFX), and two studies also tested Posaconazole (POS) or E1224 (Ravucanazole). BNZ was found to be the most efficacious trypanocidal drug compared to Nifurtimox, POS, and E1224; it also resulted in the highest percentage of adverse effects (AEs) and treatment discontinuation due to its toxicity. Adults experienced higher frequency of neurological AEs while taking BNZ or NFX compared to children. Children had a higher frequency of general AEs compared to adults while taking BNZ. Overall, BNZ is still the most efficacious, but development of new, less toxic drugs is paramount for the quality of life of patients. Studies testing combination therapies and shorter regimens are needed, as is the devising of better clinical parameters and laboratory biomarkers to evaluate treatment efficacy. Considering the variability in methodology and reporting of the studies included in the present analysis, we offer some recommendations for the improvement and replicability of clinical studies investigating pharmacological treatment of Chagas disease. These include full disclosure of methodology, standardization of outcome measures, and always collecting and reporting data on both the efficacy of trypanocidals and on safety outcomes.

Correlation between Cardiomegaly on Chest X-Ray and Left Ventricular Diameter on Echocardiography in Patients with Chagas Disease

Fundamento

Cardiomegalia pela radiografia de tórax (RXT) é preditor independente de morte em indivíduos com cardiomiopatia crônica da doença de Chagas (CCDC). Contudo, a correlação entre o aumento do índice cardiotorácico (ICT) na RXT e do diâmetro telediastólico do ventrículo esquerdo (DDVE) pela ecocardiografia (ECO) nessa população não está bem definida.

Objetivos

Analisar a relação entre cardiomegalia pela RXT e DDVE pela ECO em pacientes com doença de Chagas (DC) e sua aplicabilidade ao escore de Rassi.

Métodos

Estudo retrospectivo incluiu 63 pacientes ambulatoriais com DC avaliados por RXT e ECO. Cardiomegalia na RXT foi definida como ICT > 0,5. DDVE foi avaliado como variável contínua. Curva ROC foi utilizada para avaliar o potencial do DDVE para identificação de cardiomegalia pela RXT, com ponto de corte definido pela maior somatória de sensibilidade e especificidade.

Resultados

Idade mediana = 61 anos [intervalo interquartil: 48-68], 56% mulheres. CCDC foi identificada em 58 pacientes; 5 tinham a forma indeterminada da DC. Cardiomegalia foi detectada em 28 indivíduos. A área sob a curva ROC do DDVE para identificação de cardiomegalia foi de 0,806 (IC 95%: 0,692-0,919). O ponto de corte ótimo para DDVE foi de 60 mm (sensibilidade = 64%, especificidade = 89%). O uso do DDVE pela ECO em substituição ao ICT pela RXT alterou o escore de Rassi em 14 pacientes, e em 10 deles houve redução do risco presumido.

Conclusão

DDVE pela ECO é parâmetro adequado e com alta especificidade para distinguir entre presença e ausência de cardiomegalia na RXT na DC. (Arq Bras Cardiol. 2021; 116(1):68-74)

Chagas Cardiomyopathy as the Etiology of Suspected Coronary Microvascular Disease. A Comparison Study with Suspected Coronary Microvascular Disease of Other Etiologies

BACKGROUND

Chagas disease (CD) as neglected secondary form of suspected coronary microvascular dysfunction (CMD).

OBJECTIVES

Comparison of patients with CMD related to CD (CMD-CE) versus patients with CMD caused by other etiologies (CMD-OE).

METHODS

Of 1292 stable patients referred for invasive coronary angiography to elucidate the hemodynamic pattern and the cause of angina as a cardinal symptom in their medical history, 247 presented normal epicardial coronary arteries and 101 were included after strict exclusion criteria. Of those, 15 had suspected CMD-CE, and their clinical, hemodynamic, angiographic and scintigraphic characteristics were compared to those of the other 86 patients with suspected CDM-OE. Level of significance for all comparisons was p < 0.05.

RESULTS

Patients with suspected CMD-CE showed most anthropometric, clinical, angiographic hemodynamic and myocardial perfusion abnormalities that were statistically similar to those detected in the remaining 86 patients with suspected CMD-OE. LV diastolic dysfunction, expressed by elevated LV end-diastolic pressure was equally found in both groups. However, as compared to the group of CMD-OE the group with CMD-CE exhibited lower left ventricular ejection fraction (54.8 ± 15.9 vs 61.1 ± 11.9, p= 0.049) and a more severely impaired index of regional wall motion abnormalities (1.77 ± 0.35 vs 1.18 ± 0.26, p= 0.02) respectively for the CMD-OE and CMD-CE groups.

CONCLUSION

Chronic Chagas cardiomyopathy was a secondary cause of suspected coronary microvascular disease in 15% of 101 stable patients whose cardinal symptom was anginal pain warranting coronary angiography. Although sharing several clinical, hemodynamic, and myocardial perfusion characteristics with patients whose suspected CMD was due to other etiologies, impairment of LV segmental and global systolic function was significantly more severe in the patients with suspected CMD related to Chagas cardiomyopathy. (Arq Bras Cardiol. 2020; 115(6):1094-1101).

Sudden Cardiac Death Risk Stratification and Prevention in Chagas Disease: A Non-systematic Review of the Literature

Chagas disease is an important public health problem in Latin America. However, migration and globalisation have resulted in the increased presence of Chagas disease worldwide. Sudden cardiac death is the leading cause of death in people with Chagas disease, most often due to ventricular fibrillation. Although more common in patients with documented ventricular arrhythmias, sudden cardiac death can also be the first manifestation of Chagas disease in patients with no previous symptoms or known heart failure. Major predictors of sudden cardiac death include cardiac arrest, sustained and non-sustained ventricular tachycardia, left ventricular dysfunction, syncope and bradycardia. The authors review the predictors and risk stratification score developed by Rassi et al. for death in Chagas heart disease. They also discuss the evidence for anti-arrhythmic drugs, catheter ablation, ICDs and pacemakers for the prevention of sudden cardiac death in these patients. Given the widespread global burden, understanding the risk stratification and prevention of sudden cardiac death in Chagas disease is of timely concern.

Benznidazole decreases the risk of chronic Chagas disease progression and cardiovascular events: A long-term follow up study

BACKGROUND

Chagas disease (CD) remains an important endemic disease in Latin America. However, CD became globalized in recent decades. The majority of the chronically infected individuals did not receive etiologic treatment for several reasons, among them the most conspicuous is the lack of access to diagnosis. The impact of trypanocidal treatment on CD chronic phase, without cardiac involvement (indeterminate form ICF), is yet to be determined. We aimed to evaluate the effect of trypanocidal treatment with benznidazole (BZN) on the rate of progression to Chagas heart disease in patients with ICF.

METHODS

This is a retrospective cohort observational study including patients with ICF treated with BZN and compared to a group of non-treated patients matched for age, sex, region of origin, and the year of cohort entry. We reviewed the medical charts of all patients followed from May 1987 to June 2020 at the outpatient center of the Evandro Chagas National Institute of Infectious Diseases (INI) of the Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil. Patients' follow-up included at least one annual medical visit and one annual electrocardiogram (ECG). Echocardiographic exams were performed at baseline and during the follow-up. Disease progression from ICF to cardiac form was defined by changes in baseline ECG. Cumulative incidence and the incidence rate were described in the incidence analysis. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for the association between BZN and CD progression, cardiovascular events or death.

FINDINGS

One hundred and fourteen treated patients met the study inclusion criteria. A comparison group of 114 non-treated patients matched for age, sex, region of origin, and the year of cohort entry was also included, totalizing 228 patients. Most patients included in the study were male (70.2%), and their mean age was 31.3 (+7.4) years. Over a median follow-up of 15.1 years (ranging from 1.0 to 32.4), the cumulative CD progression incidence in treated patients was 7.9% vs. 21.1% in the non-treated group (p = 0.04) and the CD progression rate was 0.49 per 1.000 patients/year in treated patients vs. 1.10 per 1.000 patients/year for non-treated patients (p = 0.02). BZN treatment was associated with a decreased risk of CD progression in both unadjusted (HR 0.46; 95%CI 0.21 to 0.98) and adjusted (HR 0.43; 95%CI 0.19 to 0.96) models and with a decreased risk of occurrence of the composite of cardiovascular events only in the adjusted (HR 0.15; 95%CI 0.03 to 0.80) model. No association was observed between BZN treatment and mortality.

INTERPRETATION

In a long-term follow-up, BZN treatment was associated with a decreased incidence of CD progression from ICF to the cardiac form and also with a decreased risk of cardiovascular events. Therefore, our results indicate that BZN treatment for CD patients with ICF should be implemented into clinical practice.

Early impairment of myocardial deformation assessed by regional speckle-tracking echocardiography in the indeterminate form of Chagas disease without fibrosis detected by cardiac magnetic resonance

Chagas disease (CD) will account for 200,000 cardiovascular deaths worldwide over the next 5 years. Early detection of chronic Chagas cardiomyopathy (CCC) is a challenge. We aimed to test if speckle-tracking echocardiography (STE) can detect incipient myocardial damage in CD. METHODS: Among 325 individuals with positive serological tests, 25 (age 55±12yrs) were selected to compose the group with indeterminate form of Chagas disease (IFCD), based on stringent criteria of being asymptomatic and with normal EKG/X-ray studies. This group was compared with a group of 20 patients with CCC (55±11yrs) and a group of 20 non-infected matched control (NC) subjects (48±10yrs). CD patients and NC were submitted to STE and CD patients were submitted to cardiac magnetic resonance (CMR) with late gadolinium administration to detect cardiac fibrosis by the late enhancement technique. Global longitudinal strain (GLS), circumferential (GCS) and radial strain (GRS) were defined as the average of segments measured from three apical view (GLS) and short axis views (GRS and GCS). Regional left ventricular (LV) longitudinal strain (Reg LS) was measured from each of the 17 segments. Twist was measured as systolic peak difference between basal and apical rotation and indexed to LV length to express torsion. RESULTS: STE global indices (GLS, GCS, twist and torsion) were reduced in CCC vs NC (GLS: -14±6.3% vs -19.3±1.6%, p = 0.001; GCS: -13.6±5.2% vs -17.3 ±2.8%; p = 0.008; twist: 8±7° vs 14±7°, p = 0.01 and torsion: 0.96±1°/cm vs 1.9±1°/cm, p = 0.005), but showed no differences in IFCD vs NC. RegLS was reduced in IFCD vs NC in four LV segments: basal-inferior (-16.3±3.3% vs -18.6±2.2%, p = 0.013), basal inferoseptal (-13.1±3.4 vs -15.2±2.7, p = 0.019), mid-inferoseptal (-17.7±3.2 vs -19.4±2, p = 0.032) and mid-inferolateral (-15.2±3.5 vs -17.8±2.8, p = 0.014). These abnormalities in RegLS occurred in the absence of myocardial fibrosis detectable with CMR in nearly 92% of subjects with IFCD, while myocardial fibrosis was present in 65% with CCC. CONCLUSION: RegLS detects early regional impairment of myocardial strain that is independent from fibrosis in IFCD subjects.

Regional longitudinal strain is reduced in IFCD before significant fibrosis. As CD progresses to CF, global STE measurements of left ventricle (GLS, GCS, twist and torsion) and GLS of right ventricle are reduced.

Early abnormal strain pattern of CD comprises inferior, septoinferior and inferolateral segments of LV. Recognizing the regional strain pattern of Chagas cardiomyopathy may help identifying the disease even at early stages.