Noninvasive prognostic markers for cardiac death and ventricular arrhythmia in long-term follow-up of subjects with chronic Chagas' disease

Mortality risk in chronic Chagas cardiomyopathy: a systematic review and meta-analysis

Aims

This study aimed to estimate the annual mortality risk and its determinants in chronic Chagas cardiomyopathy.

Methods and results

We conducted a systematic search in MEDLINE, Web of Science Core Collection, Embase, Cochrane Library, and LILACS. Longitudinal studies published between 1 January 1946 and 24 October 2018 were included. A random‐effects meta‐analysis using the death rate over the mean follow‐up period in years was used to obtain pooled estimated annual mortality rates. Main outcomes were defined as all‐cause mortality, including cardiovascular, non‐cardiovascular, heart failure, stroke, and sudden cardiac deaths. A total of 5005 studies were screened for eligibility. A total of 52 longitudinal studies for chronic Chagas cardiomyopathy including 9569 patients and 2250 deaths were selected. The meta‐analysis revealed an annual all‐cause mortality rate of 7.9% [95% confidence interval (CI): 6.3–10.1; I² = 97.74%; T² = 0.70] among patients with chronic Chagas cardiomyopathy. The pooled estimated annual cardiovascular death rate was 6.3% (95% CI: 4.9–8.0; I² = 96.32%; T² = 0.52). The annual mortality rates for heart failure, sudden death, and stroke were 3.5%, 2.6%, and 0.4%, respectively. Meta‐regression showed that low left ventricular ejection fraction (coefficient = −0.04; 95% CI: −0.07, −0.02; P = 0.001) was associated with an increased mortality risk. Subgroup analysis based on American Heart Association (AHA) classification revealed pooled estimate rates of 4.8%, 8.7%, 13.9%, and 22.4% (P < 0.001) for B1/B2, B2/C, C, and C/D stages of cardiomyopathy, respectively.

Conclusions

The annual mortality risk in chronic Chagas cardiomyopathy is substantial and primarily attributable to cardiovascular causes. This risk significantly increases in patients with low left ventricular ejection fraction and those classified as AHA stages C and C/D.

Noninvasive prediction of late potentials in the signal-averaged ECG in patients with chronic Chagas disease

INTRODUCTION

Considering the importance of ventricular arrhythmias in the prediction of sudden cardiac death in chronic Chagas heart disease, the aim of the present study was to associate late potentials observed in the signal-averaged electrocardiogram (SAECG) with either non-sustained ventricular tachycardia in the 24-hour Holter monitoring or reduced left ventricular ejection fraction in the 2-dimension echocardiogram.

METHODS

This was a retrospective transversal study. The medical charts of 49 patients with chronic Chagas heart disease that underwent 24-hour Holter monitoring at our institution from September 2012 to December 2015 were reviewed. In the univariate analysis, variables associated with SAECG at a p value <0.05 were entered a multivariate stepwise logistic regression analysis through the model forward. A p value <0.05 was considered to have statistical significance.

RESULTS

In the univariate analysis, right bundle branch block, left atrial diameter, left ventricular systolic diameter, and left ventricular ejection fraction were associated with late potential in the SAECG. In the multivariate analysis, however, right bundle branch block and left atrial diameter were retained as independent predictors of late potentials in the SAECG.

CONCLUSIONS

Neither ventricular arrhythmias in the 24-Holter monitoring nor reduced left ventricular ejection fraction in the 2-D echocardiogram were associated with late potentials in the SAECG of patients with chronic Chagas heart disease.

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.

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.

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.

Diagnosis and management of Chagas disease and cardiomyopathy

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

Chagas heart disease: pathophysiologic mechanisms, prognostic factors and risk stratification

Chagas heart disease (CHD) results from infection with the protozoan parasite Trypanosoma cruzi and is the leading cause of infectious myocarditis worldwide. It poses a substantial public health burden due to high morbidity and mortality. CHD is also the most serious and frequent manifestation of chronic Chagas disease and appears in 20-40% of infected individuals between 10-30 years after the original acute infection. In recent decades, numerous clinical and experimental investigations have shown that a low-grade but incessant parasitism, along with an accompanying immunological response [either parasite-driven (most likely) or autoimmune-mediated], plays an important role in producing myocardial damage in CHD. At the same time, primary neuronal damage and microvascular dysfunction have been described as ancillary pathogenic mechanisms. Conduction system disturbances, atrial and ventricular arrhythmias, congestive heart failure, systemic and pulmonary thromboembolism and sudden cardiac death are the most common clinical manifestations of chronic Chagas cardiomyopathy. Management of CHD aims to relieve symptoms, identify markers of unfavourable prognosis and treat those individuals at increased risk of disease progression or death. This article reviews the pathophysiology of myocardial damage, discusses the value of current risk stratification models and proposes an algorithm to guide mortality risk assessment and therapeutic decision-making in patients with CHD.

Chagas cardiomyopathy--where do we stand after a hundred years?

A hundred years from its description, Chagas cardiomyopathy remains a challenging disease. Although successful vector-control strategies have decreased the incidence of Chagas disease in several Latin American countries, both migration to urban areas and immigration have spread the disease worldwide; and now, blood transfusion, organ transplantation, and vertical transmission are a concern. The pathogenesis of Chagas cardiomyopathy involves complex host-parasite interactions, where low-grade but incessant systemic infection and triggered autoimmune reaction are the main mechanisms for its development, with the contribution of autonomic damage and microvascular disturbances. Chagas cardiomyopathy is the most important clinical presentation of Chagas disease and comprises a wide range of manifestations, including heart failure, arrhythmias, heart blocks, sudden death, thromboembolism, and stroke. Recently, simple clinical prognostic scores have been developed to identify high-risk patients and help with management. The treatment of Chagas cardiomyopathy focuses mostly on managing heart failure, arrhythmias, and thromboembolism. The role of specific antiparasitic therapy in the chronic form is not yet defined, and a randomized trial is now under way to address this crucial point. In this article, we review the main clinical aspects of Chagas cardiomyopathy and underscore some upcoming challenges for the appropriate control, diagnosis, and management of this complex disease.

Nonlinear mathematical model for predicting long term cardiac remodeling in Chagas' heart disease: introducing the concepts of 'limiting cardiac function' and 'cardiac function deterioration period'

Cardiac remodeling has been recently investigated in long term follow-up introducing a simple exponential model to describe the time course of cardiac function and dimension changes in Chagas' disease. In the present study, an improved mathematical model to equate time course and cardiac functional changes has been proposed. Present model has been derived from previously validated intuitive assumptions and tested on data set of outpatients with chronic Chagas' disease (51.3±9.4 years old), followed for up to 10 years in Rio de Janeiro, Brazil. The variables representing cardiac status at admission were plotted against respective time derivative, which appropriately fit a second order polynomial (adjusted r(2)=0.956; p<0.001), indicating that long term cardiac remodeling followed a Verhulst-Pearl (Logistic) model. The derived Logistic model provided two output constants: a time-function (2.0·10(-3)±5.4·10(-4) months(-1)·%(-1); p<0.001) and an inferior limit for left ventricular ejection fraction (19.0±0.9%; p<0.001), standing for a limit beyond life expectation is unsustainable, in Chagas' disease. Cardiac function deterioration period was promptly derived from the model, representing the period of time following indeterminate stages of the disease when cardiac function start deteriorating, and ranged from 3 to 15.8 years. An example of data of left ventricular ejection fraction of a subject followed during 10 years illustrated the model, further validating its robustness. Present data confirms that, in chronic Chagas' disease, initial insult is connected to the progression of myocardial remodeling and introduces the concepts of limiting cardiac function and cardiac deterioration period.

An update on the management of Chagas cardiomyopathy

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, infects nearly 18 million people in Latin America and mainly affects the heart, causing heart failure, arrhythmias, heart block, thromboembolism, stroke and death. In this review, the clinical diagnosis and management of Chagas cardiomyopathy are discussed. Particular emphasis is placed on the clinical staging of patients and the use of various diagnostic tests that may be useful in individualizing treatment of the two most relevant clinical syndromes, that is, heart failure and arrhythmias. The relevance of specific treatments are discussed, stressing the important role of parasite persistence in disease pathogenesis. We also discuss new therapy modalities that may have a role in the treatment of Chagas cardiomyopathy.

Atrial mechanical remodeling and new onset atrial fibrillation in chronic Chagas' heart disease

Atrial fibrillation (AF) is a common arrhythmia, mechanistically linked to underlying heart disease. AF affects about one fifth of subjects with Chagas' heart disease and is a harbinger of poor prognosis. In a retrospective longitudinal analysis, 50 subjects were investigated in long-term follow-up for the first documented atrial fibrillation (AF) episode. During a follow-up of (mean+/-SD) 84.2+/-39.0 months, nine subjects developed AF (incidence: 3.3+/-1.0%/year). Five subjects had nonfatal embolic stroke and nine died due to cardiac causes. The relative risk of AF for stroke was 3.0 (p=0.22) and for cardiac death was 3.6 (p=0.04). A faster left atrial diameter (LAD) enlargement during follow-up was tracked in subjects with more severe cardiac damage at presentation, and large LAD was detected at both presentation (p=0.02) and end of follow-up (p=0.002) in subjects who experienced AF. Atrial remodeling in chronic Chagas' disease is associated with severity of underlying heart disease at presentation and impacts AF incidence in this population.