Effect of an exercise-based cardiac rehabilitation program on quality of life of patients with chronic Chagas cardiomyopathy: results from the PEACH randomized clinical trial.

To investigate the effect of an exercise-based cardiac rehabilitation program on the quality of life (QoL) of patients with chronic Chagas cardiomyopathy (CCC). PEACH study was a single-center, superiority randomized clinical trial of exercise training versus no exercise (control). The sample comprised Chagas disease patients with CCC, left ventricular ejection fraction < 45%, without or with HF symptoms (CCC stages B2 or C, respectively). QoL was assessed at baseline, after three months, and at the end of six months of follow-up using the SF-36 questionnaire. Patients randomized for the exercise group (n = 15) performed exercise training (aerobic, strength and stretching exercises) for 60 min, three times a week, during six months. Patients in the control group (n = 15) were not provided with a formal exercise prescription. Both groups received identical nutritional and pharmaceutical counseling during the study. Longitudinal analysis of the effects of exercise training on QoL, considering the interaction term (group × time) to estimate the rate of changes between groups in the outcomes (represented as beta coefficient), was performed using linear mixed models. Models were fitted adjusting for each respective baseline QoL value. There were significant improvements in physical functioning (ß = + 10.7; p = 0.02), role limitations due to physical problems (ß = + 25.0; p = 0.01), and social functioning (ß = + 19.2; p < 0.01) scales during the first three months in the exercise compared to the control group. No significant differences were observed between groups after six months. Exercise-based cardiac rehabilitation provided short-term improvements in the physical and mental aspects of QoL of patients with CCC.Trial registration: ClinicalTrials.gov Identifier: NCT02517632; August 7, 2015.

Autonomic denervation, myocardial hypoperfusion and fibrosis may predict ventricular arrhythmia in the early stages of Chagas cardiomyopathy.

BACKGROUND: Sudden cardiac death (SCD) can be the first clinical event of Chagas heart disease (CHD). However, current guidelines contain no clear recommendation for early cardioverter-defibrillator implantation. Using imaging modalities, we evaluated associations among autonomic denervation, myocardial hypoperfusion, fibrosis and ventricular arrhythmia in CHD. METHODS AND RESULTS: Twenty-nine patients with CHD and preserved left ventricular function underwent 123I-metaiodobenzylguanidine (MIBG) scintigraphy, 99mTc-methoxyisobutylisonitrile (MIBI) myocardial perfusion and cardiac magnetic resonance imaging (MRI). They were divided into arrhythmic (≥ 6 ventricular premature complexes/h and/or non-sustained ventricular tachycardia on 24-hour Holter, n = 15) and non-arrhythmic (< 6 ventricular premature complexes/h and no ventricular tachycardia; n = 14) groups. The arrhythmic group had higher denervation scores from MIBG imaging (23.2 ± 18.7 vs 5.6 ± 4.9; P < .01), hypoperfusion scores from MIBI SPECT (4.7 ± 6.8 vs 0.29 ± 0.6: P = .02), innervation/perfusion mismatch scores (18.5 ± 17.5 vs 5.4 ± 4.8; P = .01) and fibrosis by late gadolinium enhancement on MRI (14.3% ± 13.5% vs 4.0% ± 2.9%; P = .04) than the non-arrhythmic group. CONCLUSION: These imaging parameters were associated with ventricular arrhythmia in early CHD and may enable risk stratification and the implementation of primary preventive strategies for SCD.

Corrigendum: Impact of COVID-19 in-hospital mortality in chagas disease patients.

[This corrects the article DOI: 10.3389/fmed.2022.880796.].

Cost-effectiveness of an exercise-based cardiovascular rehabilitation program in patients with chronic Chagas cardiomyopathy in Brazil: An analysis from the PEACH study.

OBJECTIVES: The present study aimed to perform a cost-effectiveness analysis of an exercise-based cardiovascular rehabilitation (CR) program in patients with chronic Chagas cardiomyopathy (CCC). METHODS: Cost-effectiveness analysis alongside a randomised clinical trial evaluating the effects of a 6-month exercise-based CR program. The intervention group underwent 3 weekly exercise sessions. The variation of peak oxygen consumption (VO2peak ) was used as a measurement of clinical outcome. Cost information from all healthcare expenses (examinations, healthcare visits, medication and hospitalisation) were obtained from the medical records in Brazilian reais (R$) and transformed into dollars using the purchasing power parity ($PPP). The longitudinal costs variation was evaluated through linear mixed models, represented by ß coefficient, adjusted for the baseline values of the dependent variable. The cost-effectiveness evaluation was determined through an incremental cost-effectiveness ratio using the HEABS package (Stata 15.0). RESULTS: The intervention group presented higher costs with healthcare visits (ß = +3317.3; p < 0.001), hospitalisation (ß = +2810.4; p = 0.02) and total cost (ß = +6407.9; p < 0.001) after 3 months of follow-up. Costs related to healthcare visits (ß = +2455.8; p < 0.001) and total cost (ß = +4711.4; p < 0.001) remained higher in the intervention group after 6 months. The CR program showed an incremental cost-effectiveness ratio (ICER) of $PPP 1874.3 for each increase of 1.0 ml kg-1  min-1 of VO2peak . CONCLUSIONS: The CR program can be considered a cost-effective alternative and should be included as an intervention strategy in the care of patients with CCC.

Impact of COVID-19 In-hospital Mortality in Chagas Disease Patients.

The COVID-19 virus infection caused by the new SARS-CoV-2 was first identified in Rio de Janeiro (RJ), Brazil, in March 2020. Until the end of 2021, 504,399 COVID-19 cases were confirmed in RJ, and the total death toll reached 68,347. The Evandro Chagas National Institute of Infectious Diseases from Oswaldo Cruz Foundation (INI-Fiocruz) is a referral center for treatment and research of several infectious diseases, including COVID-19 and Chagas disease (CD). The present study aimed to evaluate the impact of COVID-19 on in-hospital mortality of patients with CD during the COVID-19 pandemic period. This observational, retrospective, longitudinal study evaluated all patients with CD hospitalized at INI-Fiocruz from May 1, 2020, to November 30, 2021. One hundred ten hospitalizations from 81 patients with CD (58% women; 68 ± 11 years) were evaluated. Death was the study's main outcome, which occurred in 20 cases. The mixed-effects logistic regression was performed with the following variables to test whether patients admitted to the hospital with a COVID-19 diagnosis would be more likely to die than those admitted with other diagnoses: admission diagnosis, sex, age, COVID-19 vaccination status, CD clinical classification, and the number of comorbidities. Results from multiple logistic regression analysis showed a higher risk of in-hospital mortality in patients diagnosed with COVID-19 (OR 6.37; 95% CI 1.78-22.86) compared to other causes of admissions. In conclusion, COVID-19 infection had a significant impact on the mortality risk of INI-Fiocruz CD patients, accounting for one-third of deaths overall. COVID-19 presented the highest percentage of death significantly higher than those admitted due to other causes during the COVID-19 pandemic.

Temporal changes in the clinical-epidemiological profile of patients with Chagas disease at a referral center in Brazil.

INTRODUCTION: We aimed to describe the sociodemographic, epidemiological, and clinical characteristics of patients with chronic Chagas disease (CD) at an infectious disease referral center. Changes in patient profiles over time were also evaluated. METHODS: This retrospective study included patients with CD from November 1986-December 2019. All patients underwent an evaluation protocol that included sociodemographic profile; epidemiological history; anamnesis; and physical, cardiologic, and digestive examinations. Trend differences for each 5-year period from 1986 to 2019 were tested using a nonparametric trend test for continuous and generalized linear models with binomial distribution for categorical variables. RESULTS: A total of 2,168 patients (52.2% women) were included, with a mean age of 47.8 years old. White patients with low levels of education predominated. The reported transmission mode was vectorial in 90.2% of cases. The majority came from areas with a high prevalence (52.2%) and morbidity (67.8%) of CD. The most common clinical presentation was the indeterminate form (44.9%). The number of patients referred gradually decreased and the age at admission increased during the study period, as did the patients' levels of education. CONCLUSIONS: The clinical profile of CD is characterized by a predominance of the indeterminate form of the disease. Regarding the patients who were followed up at the referral center, there was a progressive increase in the mean age and a concomitant decrease in the number of new patients. This reflects the successful control of vector and transfusion transmission in Brazil as well as the aging population of patients with CD.

Prevalence of metabolic syndrome and associated factors among patients with chronic Chagas disease.

The increase in life expectancy and the migration of individuals with Chagas disease (ChD) from rural to urban centers exposes them to the development of chronic-degenerative abnormalities that may increase the prevalence of metabolic syndrome (MetS). The present study aimed to identify the prevalence of MetS and its components in individuals with chronic ChD. This is a cross-sectional study with 361 patients of both sexes, aging >18 years, followed at a national reference center (Rio de Janeiro, Brazil). MetS diagnosis followed the International Diabetes Federation 2005 criteria. The association between the variables was determined through logistic regression models. The mean age was and 60.7±10.8 years. About half (56.2%) were female and the majority self-reported their race as mulatto (59.8%). The percentage of individuals with MetS was 40.4%. The variables independently associated with MetS were age (OR 1.06; 95%CI 1.04-1.09), high education levels (OR 0.36; 95%CI 0.17-0.79) and cardiac form with heart failure (OR 0.34; 95%CI 0.17-0.68). Therefore, a high prevalence of MetS was found in this Brazilian chronic ChD cohort. The identification of the associated factors can facilitate the development of effective approaches for preventing and managing MetS in ChD patients.

Temporal changes in the clinical-epidemiological profile of patients with Chagas disease at a referral center in Brazil

Abstract INTRODUCTION We aimed to describe the sociodemographic, epidemiological, and clinical characteristics of patients with chronic Chagas disease (CD) at an infectious disease referral center. Changes in patient profiles over time were also evaluated. METHODS This retrospective study included patients with CD from November 1986-December 2019. All patients underwent an evaluation protocol that included sociodemographic profile; epidemiological history; anamnesis; and physical, cardiologic, and digestive examinations. Trend differences for each 5-year period from 1986 to 2019 were tested using a nonparametric trend test for continuous and generalized linear models with binomial distribution for categorical variables. RESULTS A total of 2,168 patients (52.2% women) were included, with a mean age of 47.8 years old. White patients with low levels of education predominated. The reported transmission mode was vectorial in 90.2% of cases. The majority came from areas with a high prevalence (52.2%) and morbidity (67.8%) of CD. The most common clinical presentation was the indeterminate form (44.9%). The number of patients referred gradually decreased and the age at admission increased during the study period, as did the patients' levels of education. CONCLUSIONS The clinical profile of CD is characterized by a predominance of the indeterminate form of the disease. Regarding the patients who were followed up at the referral center, there was a progressive increase in the mean age and a concomitant decrease in the number of new patients. This reflects the successful control of vector and transfusion transmission in Brazil as well as the aging population of patients with CD.

Associations between Cardiac Magnetic Resonance T1 Mapping Parameters and Ventricular Arrhythmia in Patients with Chagas Disease.

Chronic Chagas disease can progress to myocardial involvement with intense fibrosis, which may predispose patients to sudden cardiac death through ventricular arrhythmia. The associations of myocardial fibrosis detected by cardiac magnetic resonance (CMR) parameters with non-sustained ventricular tachycardia (NSVT) were evaluated. This cross-sectional study included patients in early stages of Chagas disease (n = 47) and a control group (n = 15). Patients underwent cardiac evaluation, including CMR examination. Myocardial fibrosis assessment by CMR with measurement of late gadolinium enhancement (LGE), native T1, and extracellular volume (ECV) was performed. There was an increase in myocardial fibrosis CMR parameters and ventricular arrhythmias among different stages of Chagas disease, combined with a decrease in the left ventricular ejection fraction (LVEF) by CMR and also in the right ventricular systolic function by S' wave on tissue Doppler. Fibrosis mass and ECV were associated with the Rassi score, ventricular extrasystole, and E/e' ratio in a logistic regression model adjusted for age and gender. The ECV maintained an association with the presence of NSVT, even after adjustments for fibrosis mass and LVEF assessed by CMR. The receiver-operating characteristic area under the curve for global ECV (0.85; 95% CI: 0.71-0.99) and NSVT was greater than that for fibrosis mass (0.75; 95% CI: 0.54-0.96), although this difference was not statistically significant. Extracellular volume could be an early marker of increased risk of ventricular arrhythmia in Chagas disease, presenting an independent association with NSVT in the initial stages of chronic Chagas cardiomyopathy, even after adjustment for fibrosis mass and LVEF.

Progression Rate from the Indeterminate Form to the Cardiac Form in Patients with Chronic Chagas Disease: Twenty-Two-Year Follow-Up in a Brazilian Urban Cohort.

Most patients with chronic Chagas disease (CD) present the indeterminate form and are at risk to develop the cardiac form. However, the actual rate of progression to the cardiac form is still unknown. METHODS: In total, 550 patients with the indeterminate CD form were followed by means of annual electrocardiogram at our outpatient clinic. The studied endpoint was progression to cardiac form defined by the appearance of electrocardiographic changes typical of CD. The progression rate was calculated as the cumulative progression rate and the incidence progression rate per 100 patient years. RESULTS: Thirty-seven patients progressed to the CD cardiac form within a mean of 73 ± 4 8 months of follow-up, which resulted in a 6.9% cumulative progression rate and incidence rate of 1.48 cases/100 patient years. Patients who progressed were older (mean age 47.8 ± 12.2 years), had a higher prevalence of associated heart diseases (p < 0.0001), positive xenodiagnosis (p = 0.007), and were born in the most endemic Brazilian states (p = 0.018). Previous co-morbidities remained the only variable associated with CD progression after multivariate Cox proportional hazards regression analysis (p = 0.002). CONCLUSION: The progression rate to chronic CD cardiac form is low and inferior to rates previously reported in other studies.

Adverse drug events and the associated factors in patients with chronic Chagas disease.

INTRODUCTION: Herein, we aimed to identify the factors associated with adverse drug events (ADEs) in chronic Chagas disease (CD) patients. METHODS: We analyzed 320 medical notes from 295 patients. The Naranjo algorithm was applied to determine the cause of ADEs. Mixed effects logistic regression was performed to evaluate the factors associated with ADEs. RESULTS: ADEs were described in 102 medical notes (31.9%). Captopril was most frequently associated with ADEs. Age (RR 0.96; 95%CI 0.94-0.99) and cardiac C/D stages (RR 3.24; 95%CI 1.30-4.58) were the most important clinical factors associated with ADEs. CONCLUSIONS: Close follow-up is warranted for CD patients.

Effect of Physical Exercise Training in Patients With Chagas Heart Disease (from the PEACH STUDY).

Chagas heart disease (HD) is a chronic fibrosing myocarditis with high mortality. The PEACH study aimed to evaluate if exercise training can improve the functional capacity of Chagas HD patients with left ventricular dysfunction and/or heart failure. The PEACH study was a single center, parallel-group, clinical trial that randomized 30 clinical stable Chagas HD patients with left ventricular ejection fraction <45% or heart failure symptoms to either supervised exercise training 3 times/week for 6 months or a control group. Both groups had the same monthly pharmaceutical and nutritional counseling and usual care. Primary end point was functional capacity assessed by peak exercise oxygen consumption (peak VO2) obtained by cardiopulmonary exercise test. Secondary end points included other cardiopulmonary exercise test variables, cardiac function by echocardiography, body composition, muscle respiratory strength, and metabolic biomarkers. Peak VO2 increased among patients in exercise group from 17.60 ± 4.65 mlO2 kg-1 min-1 to 19.40 ± 5.51 mlO2 kg-1 min-1 while decreased in controls from 15.40 ± 6.30 mlO2 kg-1 min-1 to 12.96 ± 4.50 mlO2 kg-1 min-1, resulting in significant difference in change in peak VO2 between groups after 6 months (ß = +4.6, p = 0.004). There were significant differences between groups in changes in anaerobic threshold (ß = 3.7, p = 0.05), peak oxygen pulse (ß = +2.7, p = 0.032) and maximum minute ventilation (ß = +13.9, p < 0.0001) after 6 months of intervention. In conclusion, exercise training improved functional capacity of chronic Chagas HD patients with left ventricular dysfunction and/or heart failure.

Impact of pharmaceutical care on the quality of life of patients with heart failure due to chronic Chagas disease: Randomized clinical trial.

AIMS: Chronic Chagas disease (ChD) has high morbimortality and loss in quality of life due to heart failure (HF). Pharmaceutical care (PC) optimizes clinical treatment and can improve quality of life in HF. We evaluated if PC improves quality of life of patients with ChD and HF. METHODS: Single-blinded, randomized, controlled trial that assigned adult patients with ChD and HF (81 patients; 61 ± 11 years; 48% male) to PC (n = 40) or standard care (n = 41). Quality of life according to SF-36 and Minnesota living with HF questionnaires, incidence of drug-related problems (DRPs), and adherence to medical treatment were determined at baseline and at every 3 months for 1 year. Intention-to-treat analyses were performed by mixed linear model to verify the treatment effect on the changes of these variables throughout the intervention period. RESULTS: Relative changes from baseline to 1 year of follow-up of the domains physical functioning (+16.6 vs -8.5; P < .001), role-physical (+34.0 vs +5.2; P = .01), general health (+19.4 vs -6.1; P < .001), vitality (+11.5 vs. -5.8; P = .003), social functioning (+7.5 vs -13.3; P = .002), and mental health (+9.0 vs -3.7; P = .006) of the SF-36 questionnaire and the Minnesota living with HF questionnaire score (-12.7 vs +4.8; P < .001) were superior in the PC group than in the standard care group. Adherence to medical treatment increased as early as after 3 months of follow-up and DRPs incidence decreased after 6 months of follow-up only in the PC group. CONCLUSIONS: Patients with ChD and HF who received PC presented improved quality of life, decrease in DRP frequency, and increase in medication adherence.

Adverse drug events and the associated factors in patients with chronic Chagas disease

Abstract INTRODUCTION: Herein, we aimed to identify the factors associated with adverse drug events (ADEs) in chronic Chagas disease (CD) patients. METHODS: We analyzed 320 medical notes from 295 patients. The Naranjo algorithm was applied to determine the cause of ADEs. Mixed effects logistic regression was performed to evaluate the factors associated with ADEs. RESULTS: ADEs were described in 102 medical notes (31.9%). Captopril was most frequently associated with ADEs. Age (RR 0.96; 95%CI 0.94-0.99) and cardiac C/D stages (RR 3.24; 95%CI 1.30-4.58) were the most important clinical factors associated with ADEs. CONCLUSIONS: Close follow-up is warranted for CD patients.

A protocol update for the Selenium Treatment and Chagasic Cardiomyopathy (STCC) trial.

Several studies evaluating clinical forms of chronic Chagas disease show that about one-third of patients present cardiac involvement. Heart failure, sudden death and cardioembolic stroke are the main mechanisms of death in Chagas heart disease. The impact of specific etiologic treatment on the prognosis of patients with chronic Chagas heart disease is very limited regardless of the presence or absence of heart failure. Patients with symptomatic Chagas heart disease present serum selenium (Se) levels lower than patients without Chagas heart disease. Moreover, Se supplementation in animal models showed promising results. The aim of this trial is to estimate the effect of Se treatment on prevention of heart disease progression in patients with Chagas cardiomyopathy. However, we had to introduce some protocol modifications in order to keep trial feasibility, as follows: the primary outcome was restricted to left ventricular ejection fraction as a continuous variable, excluding disease progression; the follow-up period was decreased from 5 years to 1 year, an adjustment that might increase the participation rate of our study; the superior age limit was increased from 65 to 75 years; and diabetes mellitus was no longer considered an exclusion criterion. All of these protocol modifications were extensively debated by the research team enrolled in the design, recruitment and conduction of the clinical trial to guarantee a high scientific quality. TRIAL REGISTRATION: Clinical Trials.gov, NCT00875173 . Registered on 20 October 2008.

Evolution of anti-Trypanosoma cruzi antibody production in patients with chronic Chagas disease: Correlation between antibody titers and development of cardiac disease severity.

Chagas disease is one of the most important endemic infections in Latin America affecting around 6-7 million people. About 30-50% of patients develop the cardiac form of the disease, which can lead to severe cardiac dysfunction and death. In this scenario, the identification of immunological markers of disease progression would be a valuable tool for early treatment and reduction of death rates. In this observational study, the production of anti-Trypanosoma cruzi antibodies through a retrospective longitudinal follow-up in chronic Chagas disease patients´ cohort and its correlation with disease progression and heart commitment was evaluated. Strong inverse correlation (ρ = -0.6375, p = 0.0005) between anti-T. cruzi IgG1 titers and left ventricular ejection fraction (LVEF) in chronic Chagas cardiomyopathy (CCC) patients were observed after disease progression. Elevated levels of anti-T. cruzi IgG3 titers were detected in all T. cruzi-infected patients, indicating a lack of correlation of this IgG isotype with disease progression. Furthermore, low levels of anti-T. cruzi IgG2, IgG4, and IgA were detected in all patients through the follow-up. Although without statistical significance anti-T. cruzi IgE tends to be more reactive in patients with the indeterminate form (IND) of the disease (p = 0.0637). As this study was conducted in patients with many years of chronic disease no anti-T. cruzi IgM was detected. Taken together, these results indicate that the levels of anti-T. cruzi IgG1 could be considered to seek for promising biomarkers to predict the severity of chronic Chagas disease cardiomyopathy.

Benznidazole treatment safety: the Médecins Sans Frontières experience in a large cohort of Bolivian patients with Chagas' disease.

Background: Up to half of patients with Chagas' disease under benznidazole treatment present adverse drug reactions (ADRs) and up to one-third do not complete standard treatment. Objectives: To verify the incidence and possible factors associated with the suspension of benznidazole treatment in a large cohort of patients. Methods: We included 2075 patients treated with benznidazole during the projects managed by the medical humanitarian organization Doctors Without Borders (Médecins Sans Frontières) in Bolivia from 2009 to 2013. Benznidazole treatment was provided two or three times per day for ∼60 days at 5-7.5 mg/kg/day. A multiple logistic regression model was developed to evaluate the factors associated with permanent suspension of benznidazole treatment. Results: Permanent benznidazole treatment suspension occurred in 211 patients (10.2%) and the average time until permanent treatment suspension was 23 days. Multifactorial analysis revealed that female sex (adjusted OR = 1.70), moderate ADRs (adjusted OR = 10.57), mild ADRs (adjusted OR = 1.69) and skin disorders (adjusted OR = 4.18) were significantly associated with the permanent suspension of benznidazole treatment. Women with mild or moderate skin ADRs presented a probability of treatment interruption of 18.6% and 59.0%, respectively. Conclusions: Benznidazole treatment was safe and a large proportion of patients were able to complete a full course of benznidazole treatment under close treatment surveillance. Female sex, skin disorders and mild and moderate ADRs were independently associated with the permanent suspension of benznidazole treatment. In particular, women with moderate skin ADRs had the highest risk of benznidazole treatment interruption.

Effect of physical exercise training in patients with Chagas heart disease: study protocol for a randomized controlled trial (PEACH study).

BACKGROUND: The effects of exercise training on Chagas heart disease are still unclear. This study aimed to evaluate the effect of exercise training over functional capacity, cardiac function, quality of life, and biomarkers in Chagas heart disease. METHODS: The PEACH study is a superiority randomized clinical trial which will include subjects who meet the following criteria: Chagas heart disease with a left ventricular ejection fraction below 45 % with or without heart failure symptoms; clinical stability in the last 3 months; adherence to clinical treatment; and age above 18 years. The exclusion criteria are: pregnancy; neuromuscular limitations; smoking; evidence of non-chagasic heart disease; systemic conditions that limit exercise practice or cardiopulmonary exercise test; unavailability to attend the center three times a week during the intervention period; and practitioners of regular exercise. The intervention group will perform an exercise training intervention three times per week during 6 months and will be compared to the control group without exercise. Both groups will undergo the same monthly pharmaceutical and nutritional counseling as well as standard medical treatment according to the Brazilian consensus on Chagas disease. The primary outcome is functional capacity based on peak exercise oxygen consumption during cardiopulmonary exercise testing. Secondary outcomes are: cardiac function; body composition; muscle respiratory strength; microvascular reactivity; cardiac rhythm abnormalities; autonomic function; biochemical; oxidative stress and inflammatory biomarkers; and quality of life. Subjects will be evaluated at baseline, and at 3 and 6 months after randomization. Thirty patients will be randomly assigned into exercise or control groups at a ratio of 1:1. DISCUSSION: Findings of the present study will be useful to determine if physical exercise programs should be included as an important additional therapy in the treatment of patients with Chagas heart disease. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02517632 (registered on 6 August 2015).

Does my patient have chronic Chagas disease? Development and temporal validation of a diagnostic risk score.

INTRODUCTION: With the globalization of Chagas disease, unexperienced health care providers may have difficulties in identifying which patients should be examined for this condition. This study aimed to develop and validate a diagnostic clinical prediction model for chronic Chagas disease. METHODS: This diagnostic cohort study included consecutive volunteers suspected to have chronic Chagas disease. The clinical information was blindly compared to serological tests results, and a logistic regression model was fit and validated. RESULTS: The development cohort included 602 patients, and the validation cohort included 138 patients. The Chagas disease prevalence was 19.9%. Sex, age, referral from blood bank, history of living in a rural area, recognizing the kissing bug, systemic hypertension, number of siblings with Chagas disease, number of relatives with a history of stroke, ECG with low voltage, anterosuperior divisional block, pathologic Q wave, right bundle branch block, and any kind of extrasystole were included in the final model. Calibration and discrimination in the development and validation cohorts (ROC AUC 0.904 and 0.912, respectively) were good. Sensitivity and specificity analyses showed that specificity reaches at least 95% above the predicted 43% risk, while sensitivity is at least 95% below the predicted 7% risk. Net benefit decision curves favor the model across all thresholds. CONCLUSIONS: A nomogram and an online calculator (available at http://shiny.ipec.fiocruz.br:3838/pedrobrasil/chronic_chagas_disease_prediction/) were developed to aid in individual risk estimation.