CHronic use of Amiodarone aGAinSt Implantable cardioverter-defibrillator therapy for primary prevention of death in patients with Chagas cardiomyopathy Study: rationale and design of a randomized clinical trial

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.

Clinical trials for Chagas disease: etiological and pathophysiological treatment

Chagas disease (CD) is caused by the flagellate protozoan Trypanosoma cruzi. It is endemic in Latin America. Nowadays around 6 million people are affected worldwide, and 75 million are still at risk. CD has two evolutive phases, acute and chronic. The acute phase is mostly asymptomatic, or presenting unspecific symptoms which makes it hard to diagnose. At the chronic phase, patients can stay in the indeterminate form or develop cardiac and/or digestive manifestations. The two trypanocide drugs available for the treatment of CD are benznidazole (BZ) and nifurtimox (NFX), introduced in the clinic more than five decades ago. WHO recommends treatment for patients at the acute phase, at risk of congenital infection, for immunosuppressed patients and children with chronic infection. A high cure rate is seen at the CD acute phase but better treatment schemes still need to be investigated for the chronic phase. There are some limitations within the use of the trypanocide drugs, with side effects occurring in about 40% of the patients, that can lead patients to interrupt treatment. In addition, patients with advanced heart problems should not be treated with BZ. This is a neglected disease, discovered 114 years ago that still has no drug effective for their chronic phase. Multiple social economic and cultural barriers influence CD research. The high cost of the development of new drugs, in addition to the low economical return, results in the lack of investment. More economic support is required from governments and pharmaceutical companies on the development of more research for CD treatment. Two approaches stand out: repositioning and combination of drugs, witch drastically decrease the cost of this process, when compared to the development of a new drug. Here we discuss the progress of the clinical trials for the etiological and pathophysiological treatment for CD. In summary, more studies are needed to propose a new drug for CD. Therefore, BZ is still the best option for CD. The trials in course should clarify more about new treatment regimens, but it is already possible to indicate that dosage and time of treatment need to be adjusted.

Sustained monomorphic ventricular tachycardia as the presenting sign of Chagas' cardiomyopathy in a low prevalence setting, diagnosis and management challenges. A case report

Approximately 300,000 people in the United States are estimated to have Chagas' disease, with cardiac manifestations including arrhythmias occurring in 20%-30% of patients. We report a patient diagnosed with Chagas' cardiomyopathy after presenting in ventricular tachycardia. This patient was asymptomatic before her presentation with recurrent episodes of ventricular tachycardia, which motivated us to screen her since she was an immigrant from an endemic Chagas region. This manuscript highlights some of the characteristic cardiac magnetic resonance imaging (MRI) and electrophysiology findings present in patients with Chagas' cardiomyopathy. We also detail the management of patients with Chagas' cardiomyopathy who have suffered from ventricular tachycardia.

Defibrillation Threshold Testing and Long-term Follow-up in Chagas Disease

BACKGROUND

Sudden cardiac death is the most common cause of death in chronic Chagas cardiomyopathy (CCC). Because most CCC patients who are candidates for implantable cardioverter-defibrillators (ICD) meet criteria for high defibrillation threshold values, a defibrillator threshold test (DTT) is suggested.

OBJECTIVES

We investigated the use of DTT in CCC patients, focusing on deaths related to ICD and arrhythmic events, as well as treatment during long-term follow-up.

METHODS

We retrospectively evaluated 133 CCC patients who received an ICD mainly for secondary prevention. Demographic, clinical, laboratory data, Rassi score, and DTT data were collected, with p < 0.05 considered significant.

RESULTS

The mean patient age was 61 (SD, 13) years and 72% were men. The baseline left ventricular ejection fraction was 40 (SD, 15%) and the mean Rassi score was 10 (SD, 4). No deaths occurred during DTT and no ICD failures were documented. There was a relationship between higher baseline Rassi scores and higher DTT scores (ANOVA = 0.007). The mean time to first shock was 474 (SD, 628) days, although shock was only necessary for 28 (35%) patients with ventricular tachycardia, since most cases resolved spontaneously or through antitachycardia pacing. After a mean clinical follow-up of 1728 (SD, 1189) days, 43 deaths occurred, mainly related to progressive heart failure and sepsis.

CONCLUSIONS

A routine DTT may not be necessary for CCC patients who receive an ICD for secondary prevention. High DTT values seem to be unusual and may be related to high Rassi scores.

Prognosis of chronic Chagas heart disease and other pending clinical challenges

In this chapter, the main prognostic markers of Chagas heart disease are addressed, with an emphasis on the most recent findings and questions, establishing the basis for a broad discussion of recommendations and new approaches to managing Chagas cardiopathy. The main biological and genetic markers and the contribution of the electrocardiogram, echocardiogram and cardiac magnetic resonance are presented. We also discuss the most recent therapeutic proposals for heart failure, thromboembolism and arrhythmias, as well as current experience in heart transplantation in patients suffering from severe Chagas cardiomyopathy. The clinical and epidemiological challenges introduced by acute Chagas disease due to oral contamination are discussed. In addition, we highlight the importance of ageing and comorbidities in influencing the outcome of chronic Chagas heart disease. Finally, we discuss the importance of public policies, the vital role of funding agencies, universities, the scientific community and health professionals, and the application of new technologies in finding solutions for better management of Chagas heart disease.

Advanced management of ventricular arrhythmias in chronic Chagas cardiomyopathy

Chagas cardiomyopathy is a parasitic infection caused by Trypanosoma cruzi. Structural and functional abnormalities are the result of direct myocardial damage by the parasite, immunological reactions, dysautonomia, and microvascular alterations. Chronic Chagas cardiomyopathy (CCC) is the most serious and important manifestation of the disease, affecting up to 30% of patients in the chronic phase. It results in heart failure, arrhythmias, thromboembolism, and sudden cardiac death. As in other cardiomyopathies, scar-related reentry frequently results in ventricular tachycardia (VT). The scars typically are located in the inferior and lateral aspects of the left ventricle close to the mitral annulus extending from endocardium to epicardium. The scars may be more prominent in the epicardium than in the endocardium, so epicardial mapping and ablation frequently are required. Identification of late potentials during sinus rhythm and mid-diastolic potentials during hemodynamically tolerated VT are the main targets for ablation. High-density mapping during sinus rhythm can identify late isochronal regions that are then targeted for ablation. Preablation cardiac magnetic resonance imaging with late enhancement can identify potentials areas of arrhythmogenesis. Therapeutic alternatives for VT management include antiarrhythmic drugs and modulation of the cardiac autonomic nervous system.

Molecular and Clinical Aspects of Chronic Manifestations in Chagas Disease: A State-of-the-Art Review

Chronic manifestations of Chagas disease present as disabling and life-threatening conditions affecting mainly the cardiovascular and gastrointestinal systems. Although meaningful research has outlined the different molecular mechanisms underlying Trypanosoma cruzi’s infection and the host-parasite interactions that follow, prompt diagnosis and treatment remain a challenge, particularly in developing countries and also in those where the disease is considered non-endemic. This review intends to present an up-to-date review of the parasite’s life cycle, genetic diversity, virulence factors, and infective mechanisms, as well as the epidemiology, clinical presentation, diagnosis, and treatment options of the main chronic complications of Chagas disease.

Chagas Cardiomyopathy: From Romaña Sign to Heart Failure and Sudden Cardiac Death

Despite nearly a century of research and accounting for the highest disease burden of any parasitic disease in the Western Hemisphere, Chagas disease (CD) is still a challenging diagnosis, primarily due to its poor recognition outside of Latin America. Although initially considered endemic to Central and South America, globalization, urbanization, and increased migration have spread the disease worldwide in the last few years, making it a significant public health threat. The international medical community’s apparent lack of interest in this disease that was previously thought to be geographically restricted has delayed research on the complex host–parasite relationship that determines myocardial involvement and its differential behavior from other forms of cardiomyopathy, particularly regarding treatment strategies. Multiple cellular and molecular mechanisms that contribute to degenerative, inflammatory, and fibrotic myocardial responses have been identified and warrant further research to expand the therapeutic arsenal and impact the high burden attributed to CD. Altogether, cardiac dysautonomia, microvascular disturbances, parasite-mediated myocardial damage, and chronic immune-mediated injury are responsible for the disease’s clinical manifestations, ranging from asymptomatic disease to severe cardiac and gastrointestinal involvement. It is crucial for healthcare workers to better understand CD transmission and disease dynamics, including its behavior on both its acute and chronic phases, to make adequate and evidence-based decisions regarding the disease. This review aims to summarize the most recent information on the epidemiology, pathogenesis, clinical presentation, diagnosis, screening, and treatment of CD, emphasizing on Chagasic cardiomyopathy’s (Ch-CMP) clinical presentation and pathobiological mechanisms leading to sudden cardiac death.

Advanced Therapies for Ventricular Arrhythmias in Patients With Chagasic Cardiomyopathy: JACC State-of-the-Art Review

Chagas disease is caused by infection from the protozoan parasite Trypanosoma cruzi. Although it is endemic to Latin America, global migration has led to an increased incidence of Chagas in Europe, Asia, Australia, and North America. Following acute infection, up to 30% of patients will develop chronic Chagas disease, with most patients developing Chagasic cardiomyopathy. Chronic Chagas cardiomyopathy is highly arrhythmogenic, with estimated annual rates of appropriate implantable cardioverter-defibrillator therapies and electrical storm of 25% and 9.1%, respectively. Managing arrhythmias in patients with Chagasic cardiomyopathy is a major challenge for the clinical electrophysiologist, requiring intimate knowledge of cardiac anatomy, advanced training, and expertise. Endocardial-epicardial mapping and ablation strategy is needed to treat arrhythmias in this patient population, owing to the suboptimal long-term success rate of endocardial mapping and ablation alone. We also describe innovative approaches to improve acute and long-term clinical outcomes in patients with refractory ventricular arrhythmias following catheter ablation, such as bilateral cervicothoracic sympathectomy and bilateral renal denervation, among others.

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.

Systematic Review and Meta-Analysis of Clinical Outcome After Implantable Cardioverter-Defibrillator Therapy in Patients With Chagas Heart Disease

OBJECTIVES

The goal of this analysis was to pool data from published studies on outcomes after implantable cardioverter-defibrillator (ICD) therapy in patients with Chagas heart disease (CHD).

BACKGROUND

CHD is characterized by a high burden of ventricular arrhythmias and an increased risk of sudden cardiac death. The indications for ICD are not well established.

METHODS

An extensive literature search without language restrictions was performed to identify all studies on ICD therapy in patients with CHD. A random effects model was used to calculate percentages and 95% confidence intervals (CIs).

RESULTS

Of 397 articles screened, 13 studies (all observational) were included. There were 1,041 patients (mean age at implantation 57 ± 11 years; 64% men), most of whom (92%) received an ICD for secondary prevention. Antiarrhythmic medication consisted of amiodarone (79%) and beta-blockers (44%). Overall, the annual all-cause mortality rate was 9.0% (95% CI: 6.9 to 11.7) in 2.8 ± 1.9 years of follow-up, and the annual sudden cardiac death rate was 2.0% (95% CI: 1.3 to 3.3) in 2.6 ± 1.9 years. In addition, 24.8% (95% CI: 15.7 to 37.0) of patients received 1 or more appropriate interventions (shocks or antitachycardia pacing), 4.7% (95% CI: 3.2 to 6.9) received inappropriate shocks, and 9.1% (95% CI: 5.5 to 14.7) had electric storms annually.

CONCLUSIONS

In patients with an ICD, annual all-cause mortality rate was 9%. Appropriate ICD interventions and electric storms were frequent, occurring at a rate of 25% and 9% per year, respectively. Inappropriate ICD shocks were not infrequent (5% per year). The benefits and risks of ICD therapy in patients with CHD should be carefully weighed until data from better studies become available.

A cohort study of cardiac resynchronization therapy in patients with chronic Chagas cardiomyopathy

Aims

Cardiac resynchronization therapy (CRT) is an established procedure for patients with heart failure. However, trials evaluating its efficacy did not include patients with chronic Chagas cardiomyopathy (CCC). We aimed to assess the role of CRT in a cohort of patients with CCC.

Methods and results

This retrospective study compared the outcomes of CCC patients who underwent CRT with those of dilated (DCM) and ischaemic cardiomyopathies (ICM). The primary endpoint was all-cause mortality and the secondary endpoints were the rate of non-advanced New York Heart Association (NYHA) class 12 months after CRT and echocardiographic changes evaluated at least 6 months after CRT. There were 115 patients in the CCC group, 177 with DCM, and 134 with ICM. The annual mortality rates were 25.4%, 10.4%, and 11.3%, respectively (P < 0.001). Multivariate analysis adjusted for potential confounders showed that the CCC group had a two-fold [hazard ratio 2.34 (1.47-3.71), P < 0.001] higher risk of death compared to the DCM group. The rate of non-advanced NYHA class 12 months after CRT was significantly higher in non-CCC groups than in the CCC group (DCM 74.0% vs. ICM 73.9% vs. 56.5%, P < 0.001). Chronic Chagas cardiomyopathy and ICM patients had no improvement in the echocardiographic evaluation, but patients in the DCM group had an increase in left ventricular ejection fraction and a decrease in left ventricular end-diastolic diameter.

Conclusion

This study showed that CCC patients submitted to CRT have worse prognosis compared to patients with DCM and ICM who undergo CRT. Studies comparing CCC patients with and without CRT are warranted.

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.

Amiodarone for arrhythmia in patients with Chagas disease: A systematic review and individual patient data meta-analysis

Background

Chagas disease is a neglected chronic condition caused by Trypanosoma cruzi, with high prevalence and burden in Latin America. Ventricular arrhythmias are common in patients with Chagas cardiomyopathy, and amiodarone has been widely used for this purpose. The aim of our study was to assess the effect of amiodarone in patients with Chagas cardiomyopathy.

Methodology

We searched MEDLINE, Embase and LILACS up to January 2018. Data from randomized and observational studies evaluating amiodarone use in Chagas cardiomyopathy were included. Two reviewers selected the studies, extracted data and assessed risk of bias. Overall quality of evidence was accessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Principal findings

We included 9 studies (3 before-after studies, 5 case series and 1 randomized controlled trial). Two studies with a total of 38 patients had the full dataset, allowing individual patient data (IPD) analysis. In 24-hour Holter, amiodarone reduced the number of ventricular tachycardia episodes in 99.9% (95%CI 99.8%-100%), ventricular premature beats in 93.1% (95%CI 82%-97.4%) and the incidence of ventricular couplets in 79% (RR 0.21, 95%CI 0.11–0.39). Studies not included in the IPD analysis showed a reduction of ventricular premature beats (5 studies), ventricular tachycardia (6 studies) and ventricular couplets (1 study). We pooled the incidence of adverse side effects with random effects meta-analysis; amiodarone was associated with corneal microdeposits (61.1%, 95%CI 19.0–91.3, 5 studies), gastrointestinal events (16.1%, 95%CI 6.61–34.2, 3 studies), sinus bradycardia (12.7%, 95%CI 3.71–35.5, 6 studies), dermatological events (10.6%, 95%CI 4.77–21.9, 3 studies) and drug discontinuation (7.68%, 95%CI 4.17–13.7, 5 studies). Quality of evidence ranged from moderate to very low.

Conclusions

Amiodarone is effective in reducing ventricular arrhythmias, but there is no evidence for hard endpoints (sudden death, hospitalization). Although our findings support the use of amiodarone, it is important to balance the potential benefits and harms at the individual level for decision-making.

Chagas disease is a chronic neglected tropical disease, with high prevalence and burden in Latin America. About 30% of chronically infected patients develop Chagas cardiomyopathy. Ventricular arrhythmias are common in patients with Chagas cardiomyopathy and treatment approaches include medications, resynchronization therapy, and implantable cardioverter defibrillator. Studies published from 1980 to 1990 have evaluated the effect of amiodarone. According to our systematic review and individual patient meta-analysis, amiodarone reduced ventricular tachycardia, ventricular premature beats and incidence of ventricular couplets. Although the strong evidence of clinical benefit with arrhythmia reduction, this information should be interpreted with caution, since arrhythmia is a surrogate outcome and since its clinical impact on death and hospitalization reduction over time is not clear. Little information was identified related to hard endpoints. Regarding side effects, our systematic review observed that amiodarone was associated with corneal microdeposits, gastrointestinal events, sinus bradycardia, dermatological events, pneumonitis, hypothyroidism and drug discontinuation. The currently available evidence shows that amiodarone seems to be an effective antiarrhythmic drug for patients with Chagas disease, especially in settings where an implantable cardioverter defibrillator is not available or affordable, but that a balance between potential benefits and harms at the individual level is needed.

Treatment of Chagas Disease in the United States

PURPOSE OF REVIEW

Chagas disease (CD) is endemic to much of Latin America, but also present in the United States (U.S.). Following a lengthy asymptomatic period, CD produces serious cardiac or gastrointestinal complications in 30-40% of people. Less than 1% of the estimated six million cases in the Americas, including 326,000-347,000 in the U.S., are diagnosed. Infected persons are typically unaware and the bulk of clinicians are unfamiliar with current treatment guidelines. This review provides U.S. and other clinicians with the latest knowledge of CD treatment.

RECENT FINDINGS

Chagas cardiomyopathy (CCM) causes severe fibrosis and autonomic damage in the myocardium. Eliminating the parasite through antitrypanosomal therapy with benznidazole, a nitroimidazole derivative or nifurtimox, a nitrofuran compound, potentially prevents heart failure and other sequelae of advanced CCM. Benznidazole, recently approved by the U.S. Food and Drug Administration (FDA) for children 2-12 years old, is the first-line therapy; optimal dosages are currently being studied. Antitrypanosomal therapy prevents congenital transmission; produces high cure rates for acute, congenital, and early chronic cases; and improves clinical outcomes in adult chronic indeterminate cases. However, this benefit was not observed in a large clinical trial that included patients with advanced CCM.

SUMMARY

Treatment with antitrypanosomal drugs can cure CD in acute, congenital, and early chronic cases and provides improved clinical outcomes for chronic indeterminate cases. This treatment should be offered as early as possible, before advanced CCM develops.

Long-term follow-up of Chagas heart disease patients receiving an implantable cardioverter-defibrillator for secondary prevention

BACKGROUND

Chagas heart disease (CHD) is a dilated cardiomyopathy characterized by malignant ventricular arrhythmias and increased risk of sudden cardiac death (SCD). Much controversy exists concerning the efficacy of implantable cardioverter-defibrillator (ICDs) in CHD because of mixed results observed. We report our long-term experience with ICDs for secondary prevention in CHD, with the specific aim of assessing the results in groups with preserved or depressed global left ventricular function.

METHODS

111 patients (75 males; 60 ± 12 years) were followed for 1,948 ± 1,275 days after ICD. Time to death was the primary outcome; LVEF ≤ 45% the exposure; and age, gender, and ICD therapy delivery the potential confounders. We used time-to-event methods and Cox proportional models for analysis, censoring observations at time of death or at 5-year follow-up in survivors.

RESULTS

Seventy-two percent of the patients presented at least one sustained ventricular arrhythmia requiring appropriate therapy, and only three patients received inappropriate therapy. Death occurred in 50 (45%) patients, with an annual mortality rate of 8.4%, mostly due to refractory heart failure or noncardiac causes. Unadjusted survival rates were significantly distinct between patients with left ventricular ejection fraction (LVEF) ≤ 45% (26 deaths), 50.5% (95% confidence interval [CI]: 36.2%-63.2%) when compared to patients with LVEF > 45% (10 deaths), 77.6% (95% CI: 62.3%-87.3%, P < 0.01). After adjusting for confounders, low LVEF (hazard ratio [HR]: 5.2, 95% CI: 2.3-11.6), age (HR: 1.04, 95% CI: 1.01-1.07), and female gender (HR: 3.97, 95% CI: 1.85-8.54) were independently associated with the outcome.

CONCLUSIONS

ICDs successfully aborted life-threatening arrhythmias in CHD patients. Impaired left ventricular function predicted higher mortality in CHD patients with an ICD for secondary prevention of SCD.

Chronic Chagas Heart Disease Management: From Etiology to Cardiomyopathy Treatment

Trypanosoma cruzi (T. cruzi) infection is endemic in Latin America and is becoming a worldwide health burden. It may lead to heterogeneous phenotypes. Early diagnosis of T. cruzi infection is crucial. Several biomarkers have been reported in Chagas heart disease (ChHD), but most are nonspecific for T. cruzi infection. Prognosis of ChHD patients is worse compared with other etiologies, with sudden cardiac death as an important mode of death. Most ChHD patients display diffuse myocarditis with fibrosis and hypertrophy. The remodeling process seems to be associated with etiopathogenic mechanisms and neurohormonal activation. Pharmacological treatment and antiarrhythmic therapy for ChHD is mostly based on results for other etiologies. Heart transplantation is an established, valuable therapeutic option in refractory ChHD. Implantable cardioverter-defibrillators are indicated for prevention of secondary sudden cardiac death. Specific etiological treatments should be revisited and reserved for select patients. Understanding and management of ChHD need improvement, including development of randomized trials.

Mitral Subvalvular Aneurysm in a Patient with Chagas Disease and Recurrent Episodes of Ventricular Tachycardia

Subvalvular left ventricular aneurysm is a rare disease of obscure origin suggesting unique causes such as congenital, traumatic, and inflammatory or infectious diseases. Its mortality is closely related to heart failure, mitral insufficiency, thromboembolic phenomena, and cardiac arrhythmias. Although association with coronary artery disease is not described, the compression of epicardial vessels by the aneurysm may lead to ischemic manifestations. We report here a case of mitral subvalvular left ventricular aneurysm of probable chagasic origin, in a patient with normal left ventricular function evolving with repeated episodes of monomorphic ventricular tachycardia, despite noninducible electrophysiological testing and the use of optimal medical treatment, including amiodarone. The indication for implantable cardioverter-defibrillator in patients with Chagas cardiomyopathy and segmental wall motion abnormalities but without global systolic dysfunction remains unclear in literature, even in the presence of complex ventricular arrhythmias. A brief review of the literature on morphological features, diagnosis, prognosis, and treatment will be also discussed.

High throughput screening for anti-Trypanosoma cruzi drug discovery

The discovery of new therapeutic options against Trypanosoma cruzi, the causative agent of Chagas disease, stands as a fundamental need. Currently, there are only two drugs available to treat this neglected disease, which represents a major public health problem in Latin America. Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable. Thus, there is an urgent need for new, improved anti–T. cruzi drugs. With the objective to reliably accelerate the drug discovery process against Chagas disease, several advances have been made in the last few years. Availability of engineered reporter gene expressing parasites triggered the development of phenotypic in vitro assays suitable for high throughput screening (HTS) as well as the establishment of new in vivo protocols that allow faster experimental outcomes. Recently, automated high content microscopy approaches have also been used to identify new parasitic inhibitors. These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti–T. cruzi drug entities in the near future, are reviewed here.