The paradox of survival results after heart transplantation for cardiomyopathy caused by Trypanosoma cruzi. First Guidelines Group for Heart Transplantation of the Brazilian Society of Cardiology

Chagas disease in immunocompromised patients

SUMMARYAs Chagas disease remains prevalent in the Americas, it is important that healthcare professionals and researchers are aware of the screening, diagnosis, monitoring, and treatment recommendations for the populations of patients they care for and study. Management of Trypanosoma cruzi infection in immunocompromised hosts is challenging, particularly because, regardless of antitrypanosomal treatment status, immunocompromised patients with Chagas disease are at risk for T. cruzi reactivation, which can be lethal. Evidence-based practices to prevent and manage T. cruzi reactivation vary depending on the type of immunocompromise. Here, we review available data describing Chagas disease epidemiology, testing, and management practices for various populations of immunocompromised individuals, including people with HIV and patients undergoing solid organ and hematopoietic stem cell transplantation.

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.

Survival of Heart Transplant Patients with Chagas' Disease Under Different Antiproliferative Immunosuppressive Regimens

Chagas' disease (CD) is an important cause of heart transplantation (HT). The main obstacle is Chagas' disease reactivation (CDR), usually associated to high doses of immunosuppressants. Previous studies have suggested an association of mycophenolate mofetil with increased CDR. However, mortality predictors are unknown. To identify mortality risk factors in heart transplant patients with CD and the impact of antiproliferative regimen on survival. Retrospective study with CD patients who underwent HT between January 2004 and September 2020, under immunosuppression protocol that prioritized azathioprine and change to mycophenolate mofetil in case of rejection. We performed univariate regression to identify mortality predictors; and compared survival, rejection and evidence of CDR between who received azathioprine, mycophenolate mofetil and those who changed from azathioprine to mycophenolate mofetil after discharge ("Change" group). A p-value < 0.05 was considered statistically significant. Eighty-five patients were included, 54.1% men, median age 49 (39-57) years, and 91.8% were given priority in waiting list. Nineteen (22.4%) used azathioprine, 37 (43.5%) mycophenolate mofetil and 29 (34.1%) switched therapy; survival was not different between groups, 2.9 (1.6-5.0) x 2.9 (1.8-4.8) x 4.2 (2.0-5.0) years, respectively; p=0.4. There was no difference in rejection (42%, 73% and 59% respectively; p=0.08) or in CDR (T. cruzi positive by endomyocardial biopsy 5% x 11% x 7%; p=0.7; benznidazole use 58% x 65% x 69%; p=0.8; positive PCR for T. cruzi 20% x 68% x 42% respectively; p=0.1) rates. This retrospective study did not show difference in survival in heart transplant patients with CD receiving different antiproliferative regimens. Mycophenolate mofetil was not associated with statistically higher rates of CDR or graft rejection in this cohort. New randomized clinical trials are necessary to address this issue.

Transplantation for chagas' disease: closing the knowledge gap

PURPOSE OF THE REVIEW

This review examines the most recent literature on the epidemiology and treatment of Chagas Disease and the risk of Chagas Disease Reactivation and donor-derived disease in solid organ transplant recipients.

RECENT FINDINGS

Chagas disease is caused by infection with the parasite Trypansoma cruzi . In nonendemic countries the disease is seen primarily in immigrants from Mexico, Central America and South America where the disease is endemic. Benznidazole or nifurtimox can be used for treatment. Posaconazole and fosravuconazole did not provide any additional benefit compared to benznidazole alone or in combination. A phase 2 randomized controlled trial suggests that shorter or reduced dosed regimes of benznidazole could be used. Based on a large randomized controlled trial, benznidazole is unlikely to have a significant preventive effect for established Chagas cardiomyopathy. Transplantation has become the treatment of choice for individuals with refractory Chagas cardiomyopathy. Cohort studies show similar posttransplant outcomes for these patients compared to other indications. Transplant candidates and donors with chronic T. cruzi infection are at risk for Chagas disease reactivation and transmitting infection. Screening them via serology is the first line of prevention. Recipients with chronic infection and those receiving organs from infected donors should undergo sequential monitoring with polymerase chain reaction for early detection of reactivation and preemptive treatment with antitrypanosomal therapy.

SUMMARY

Patients with chronic T. cruzi infection can be safely transplanted and be noncardiac organ donors.

Long-term Survival Following Heart Transplantation for Chagas Versus Non-Chagas Cardiomyopathy: A Single-center Experience in Northeastern Brazil Over 2 Decades

Data on post–heart transplant (HT) survival of patients with Chagas cardiomyopathy (CC) are scarce. We sought to evaluate post-HT survival in patients with CC as compared with other causes of heart failure across different eras of HT.

Updated Estimates and Mapping for Prevalence of Chagas Disease among Adults, United States

Geographic scale estimates of disease in older Latin America–born US residents may be useful for prevention and early recognition of chronic sequelae.

We combined American Community Survey data with age-specific Trypanosoma cruzi prevalence derived from US surveys and World Health Organization reports to yield estimates of Chagas disease in the United States, which we mapped at the local level. In addition, we used blood donor data to estimate the relative prevalence of autochthonous T. cruzi infection. Our estimates indicate that 288,000 infected persons, including 57,000 Chagas cardiomyopathy patients and 43,000 infected reproductive-age women, currently live in the United States; 22–108 congenital infections occur annually. We estimated ≈10,000 prevalent cases of locally acquired T. cruzi infection. Mapping shows marked geographic heterogeneity of T. cruzi prevalence and illness. Reliable demographic and geographic data are key to guiding prevention and management of Chagas disease. Population-based surveys in high prevalence areas could improve the evidence base for future estimates. Knowledge of the demographics and geographic distribution of affected persons may aid practitioners in recognizing Chagas disease.

Efficacy and Safety of Granulocyte-Colony Stimulating Factor Therapy in Chagas Cardiomyopathy: A Phase II Double-Blind, Randomized, Placebo-Controlled Clinical Trial

Aim

Previous studies showed that granulocyte-colony stimulating factor (G-CSF) improved heart function in a mice model of Chronic Chagas Cardiomyopathy (CCC). Herein, we report the interim results of the safety and efficacy of G-CSF therapy vs. placebo in adults with Chagas cardiomyopathy.

Methods

Patients with CCC, New York Heart Association (NYHA) functional class II to IV and left ventricular ejection fraction (LVEF) 50% or below were included. A randomization list using blocks of 2 and 4 and an allocation rate of 1:1 was generated by R software which was stratified by functional class. Double blinding was done to both arms and assessors were masked to allocations. All patients received standard heart failure treatment for 2 months before 1:1 randomization to either the G-CSF (10 mcg/kg/day subcutaneously) or placebo group (1 mL of 0.9% saline subcutaneously). The primary endpoint was either maintenance or improvement of NYHA class from baseline to 6–12 months after treatment, and intention-to-treat analysis was used.

Results

We screened 535 patients with CCC in Salvador, Brazil, of whom 37 were randomized. Overall, baseline characteristics were well-balanced between groups. Most patients had NYHA class II heart failure (86.4%); low mean LVEF was 32 ± 7% in the G-CSF group and 33 ± 10% in the placebo group. Frequency of primary endpoint was 78% (95% CI 0.60–0.97) vs. 66% (95% CI 0.40–0.86), p = 0.47, at 6 months and 68% (95% CI 0.43–0.87) vs. 72% (95% CI 0.46–0.90), p = 0.80, at 12 months in placebo and G-CSF groups, respectively. G-CSF treatment was safe, without any related serious adverse events. There was no difference in mortality between both arms, with five deaths (18.5%) in treatment vs. four (12.5%) in the placebo arm. Exploratory analysis demonstrated that the maximum rate of oxygen consumption during exercise (VO₂ max) showed an improving trend in the G-CSF group.

Conclusion

G-CSF therapy was safe and well-tolerated in 12 months of follow-up. Although prevention of symptom progression could not be demonstrated in the present study, our results support further investigation of G-CSF therapy in Chagas cardiomyopathy patients.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT02154269].

T-Cell Subpopulations Exhibit Distinct Recruitment Potential, Immunoregulatory Profile and Functional Characteristics in Chagas versus Idiopathic Dilated Cardiomyopathies

Chronic Chagas cardiomyopathy (CCC) is one of the deadliest cardiomyopathies known and the most severe manifestation of Chagas disease, which is caused by infection with the parasite Trypanosoma cruzi. Idiopathic dilated cardiomyopathies (IDC) are a diverse group of inflammatory heart diseases that affect the myocardium and are clinically similar to CCC, often causing heart failure and death. While T-cells are critical for mediating cardiac pathology in CCC and IDC, the mechanisms underlying T-cell function in these cardiomyopathies are not well-defined. In this study, we sought to investigate the phenotypic and functional characteristics of T-cell subpopulations in CCC and IDC, aiming to clarify whether the inflammatory response is similar or distinct in these cardiomyopathies. We evaluated the expression of systemic cytokines, determined the sources of the different cytokines, the expression of their receptors, of cytotoxic molecules, and of molecules associated with recruitment to the heart by circulating CD4⁺, CD8⁺, and CD4-CD8- T-cells from CCC and IDC patients, using multiparameter flow cytometry combined with conventional and unsupervised machine-learning strategies. We also used an in silico approach to identify the expression of genes that code for key molecules related to T-cell function in hearts of patient with CCC and IDC. Our data demonstrated that CCC patients displayed a more robust systemic inflammatory cytokine production as compared to IDC. While CD8⁺ T-cells were highly activated in CCC as compared to IDC, CD4⁺ T-cells were more activated in IDC. In addition to differential expression of functional molecules, these cells also displayed distinct expression of molecules associated with recruitment to the heart. In silico analysis of gene transcripts in the cardiac tissue demonstrated a significant correlation between CD8 and inflammatory, cytotoxic and cardiotropic molecules in CCC transcripts, while no correlation with CD4 was observed. A positive correlation was observed between CD4 and perforin transcripts in hearts from IDC but not CCC, as compared to normal tissue. These data show a clearly distinct systemic and local cellular response in CCC and IDC, despite their similar cardiac impairment, which may contribute to identifying specific immunotherapeutic targets in these diseases.

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 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.

Chagas Disease Infection Reactivation after Heart Transplant

Chagas disease, caused by a Trypanosona cruzi infection, is one of the main causes of heart failure in Latin America. It was originally a health problem endemic to South America, predominantly affecting residents of poor rural areas. With globalization and increasing migratory flows from these areas to large cities, the immigration of T. cruzi chronically-infected people to developed, non-endemic countries has occurred. This issue has emerged as an important consideration for heart transplant professionals. Currently, Chagas patients with end-stage heart failure may need a heart transplantation (HTx). This implies that in post-transplant immunosuppression therapy to avoid rejection in the recipient, there is the possibility of T. cruzi infection reactivation, increasing the morbidity and mortality rates. The management of heart transplant recipients due to Chagas disease requires awareness for early recognition and parasitic treatment of T. cruzi infection reactivation. This issue poses challenges for heart transplant professionals, especially regarding the differential diagnosis between rejection and reactivation episodes. The aim of this review is to discuss the complexity of the Chagas disease reactivation phenomenon in patients submitted to HTx for end-stage chagasic cardiomyopathy.

The current drug discovery landscape for trypanosomiasis and leishmaniasis: Challenges and strategies to identify drug targets

Human trypanosomiasis and leishmaniasis are vector-borne neglected tropical diseases caused by infection with the protozoan parasites Trypanosoma spp. and Leishmania spp., respectively. Once restricted to endemic areas, these diseases are now distributed worldwide due to human migration, climate change, and anthropogenic disturbance, causing significant health and economic burden globally. The current chemotherapy used to treat these diseases has limited efficacy, and drug resistance is spreading. Hence, new drugs are urgently needed. Phenotypic compound screenings have prevailed as the leading method to discover new drug candidates against these diseases. However, the publication of the complete genome sequences of multiple strains, advances in the application of CRISPR/Cas9 technology, and in vivo bioluminescence-based imaging have set the stage for advancing target-based drug discovery. This review analyses the limitations of the narrow pool of available drugs presently used for treating these diseases. It describes the current drug-based clinical trials highlighting the most promising leads. Furthermore, the review presents a focused discussion on the most important biological and pharmacological challenges that target-based drug discovery programs must overcome to advance drug candidates. Finally, it examines the advantages and limitations of modern research tools designed to identify and validate essential genes as drug targets, including genomic editing applications and in vivo imaging.

Chagas Disease in the United States: a Public Health Approach

Trypanosoma cruzi is the etiological agent of Chagas disease, usually transmitted by triatomine vectors. An estimated 20 to 30% of infected individuals develop potentially lethal cardiac or gastrointestinal disease. Sylvatic transmission cycles exist in the southern United States, involving 11 triatomine vector species and infected mammals such as rodents, opossums, and dogs. Nevertheless, imported chronic T. cruzi infections in migrants from Latin America vastly outnumber locally acquired human cases. Benznidazole is now FDA approved, and clinical and public health efforts are under way by researchers and health departments in a number of states. Making progress will require efforts to improve awareness among providers and patients, data on diagnostic test performance and expanded availability of confirmatory testing, and evidence-based strategies to improve access to appropriate management of Chagas disease in the United States.

Reactivation of Chagas disease in a heart transplant patient infected by sylvatic Trypanosoma cruzi discrete typing unit I

Heart transplantation is an effective treatment for Chagas disease patients with severe cardiomyopathy. However, Trypanosoma cruzi reactivation is of great concern. The T. cruzi parasite is classified into six discrete typing units (DTUs identified as TcI-TcVI). It is unknown whether there is an association between T. cruzi genetic lineages and the different clinical manifestations of the disease. We report the case of a 51-year-old man who received a heart transplantation and presented with a reactivation of the disease. The molecular characterization of the parasite showed that the reactivation was related to specific infection by a DTU I (TcISYL) parasite.

Reactivation of Chagas disease among heart transplant recipients in the United States, 2012-2016

BACKGROUND

Heart transplantation has been shown to be a safe and effective intervention for progressive cardiomyopathy from chronic Chagas disease. However, in the presence of the immunosuppression required for heart transplantation, the likelihood of Chagas disease reactivation is significant. Reactivation may cause myocarditis resulting in allograft dysfunction and the rapid onset of congestive heart failure. Reactivation rates have been well documented in Latin America; however, there is a paucity of data regarding the risk in non-endemic countries.

METHODS

We present our experience with 31 patients with chronic Chagas disease who underwent orthotopic heart transplantation in the United States from 2012 to 2016. Patients were monitored following a standard schedule.

RESULTS

Of the 31 patients, 19 (61%) developed evidence of reactivation. Among the 19 patients, a majority (95%) were identified by laboratory monitoring using polymerase chain reaction testing. One patient was identified after the onset of clinical symptoms of reactivation. All subjects with evidence of reactivation were alive at follow-up (median: 60 weeks).

CONCLUSIONS

Transplant programs in the United States are encouraged to implement a monitoring program for heart transplant recipients with Chagas disease. Our experience using a preemptive approach of monitoring for Chagas disease reactivation was effective at identifying reactivation before symptoms developed.

Solid Organ Transplant and Parasitic Diseases: A Review of the Clinical Cases in the Last Two Decades

The aim of this study was to evaluate the occurrence of parasitic infections in solid organ transplant (SOT) recipients. We conducted a systematic review of literature records on post-transplant parasitic infections, published from 1996 to 2016 and available on PubMed database, focusing only on parasitic infections acquired after SOT. The methods and findings of the present review have been presented based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. From data published in the literature, the real burden of parasitic infections among SOT recipients cannot really be estimated. Nevertheless, publications on the matter are on the increase, probably due to more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents; (ii) the “population shift” resulting from immigration and travels to endemic areas, and (iii) the increased attention directed to diagnosis/notification/publication of cases. Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of awareness, identification, and pre-emptive therapy are needed in transplant recipients.

Heart transplant outcomes in patients with Chagas cardiomyopathy in the United States

BACKGROUND

Chagas cardiomyopathy (CC) is one of the chronic manifestations of Trypanosoma cruzi (T. cruzi) infection and is among the leading reasons for heart transplantation (HT) in Latin America. Chagas disease is also present in areas with large Hispanic communities in the United States. Our objective is to evaluate the outcomes of cardiac allograft recipients with the diagnosis of CC in the United States.

METHODS AND RESULTS

We identified 25 adult patients with CC and 15 930 with idiopathic dilated cardiomyopathy (IDCMP) who underwent HT between 1987 and 2015. CC patients were mostly Hispanics, had lower mean pulmonary artery pressure (23 vs 29 mm Hg, P = .035) and lower BMI (24 vs 26, P = .007). Patients with CC were more likely to be supported with a total artificial heart (TAH) as bridge to transplant (P = .009). There were no statistical differences for overall mortality and graft survival between CC and IDCMP cardiac allograft recipients. Induction therapy and mycophenolate mofetil (MMF) use were associated with higher rate of infection in Chagas patients.

CONCLUSIONS

Heart transplantation recipients with CC diagnosis appear to have similar outcomes to IDCMP patients. Induction therapy and MMF use may be associated with higher risk of infection in CC patients who underwent transplantation.

Heart Failure Secondary to Chagas Disease: an Emerging Problem in Non-endemic Areas

Chagas disease affects millions of people worldwide. Though the majority of infected individuals remain asymptomatic, approximately 30 % of patients progress to develop cardiac manifestations and eventual heart failure. While vectorial transmission occurs predominantly in South America, Central America, and Mexico, millions of people originally from these endemic regions immigrate to non-endemic countries in North America, Europe, and Asia. Outside of rare specialized centers, health-care providers lack experience diagnosing and treating this disease. This lack of experience likely leads to far fewer Chagas disease patients being diagnosed than what actually exist in non-endemic countries, with subsequent adverse effect on patient outcomes and health-care expenses. Underdiagnosis increases the risk of developing cardiomyopathy, associated heart failure, and life-threatening ventricular arrhythmias as the disease progresses.

Heart transplantation for Chagas cardiomyopathy

Chagas disease is an endemic disease in Latin America that is increasingly found in non-endemic areas all over the world due to the flow of migrants from Central and South America. We present the case of a Brazilian immigrant in Portugal who underwent orthotopic heart transplantation for end-stage Chagas cardiomyopathy. Immunosuppressive therapy included prednisone, mycophenolate mofetil and tacrolimus. Twelve months after the procedure she is asymptomatic, with good graft function, and with no evidence of complications such as graft rejection, opportunistic infections, neoplasms or reactivation of Trypanosoma cruzi infection. By reporting the first case in Portugal of heart transplantation for Chagas cardiomyopathy, we aim to increase awareness of Chagas disease as an emerging global problem and of Chagas cardiomyopathy as a serious complication for which heart transplantation is a valuable therapeutic option.

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.

Early polymerase chain reaction detection of Chagas disease reactivation in heart transplant patients

BACKGROUND

Heart transplantation is a valuable therapeutic option for Chagas disease patients with severe cardiomyopathy. During patient follow-up, the differential diagnosis between cardiac transplant rejection and Chagas disease infection reactivation remains a challenging task, which hinders rapid implementation of the appropriate treatment. Herein we investigate whether polymerase chain reaction (PCR) strategies could facilitate early detection of Trypanosoma cruzi (T cruzi) in transplanted endomyocardial biopsies (EMBs).

METHODS

In this study we analyzed 500 EMB specimens obtained from 58 chagasic cardiac transplant patients, using PCR approaches targeted to nuclear (rDNA 24Sα) and kinetoplastid (kDNA) markers, and compared the efficiency of these approaches with that of other tests routinely used.

RESULTS

T cruzi DNA was detected in 112 EMB specimens derived from 39 patients (67.2%). The first positive result occurred at a median 1.0 month post-transplant. Conventional histopathologic, blood smear and hemoculture analyses showed lower sensitivity and higher median time to the first positive result. Patient follow-up revealed that 31 of 39 PCR-positive cases presented clinical reactivation of Chagas disease at different time-points after transplantation. PCR techniques showed considerable sensitivity (0.82) and specificity (0.60), with area under the receiver operating characteristic (ROC) curves of 0.708 (p = 0.001). Moreover, PCR techniques anticipated the clinical signs of Chagas disease reactivation by up to 36 months, with a median time of 6 months and an average of 9.1 months.

CONCLUSIONS

We found a good association between the PCR diagnosis and the clinical signs of the disease, indicating that the PCR approaches used herein are suitable for early diagnosis of Chagas disease reactivation, with high potential to assist physicians in treatment decisions. For this purpose, an algorithm is proposed for surveillance based on the molecular tests.

Chagas Heart Failure in Patients from Latin America

Physicians working in Europe and the United States should suspect Chagas heart failure in every patient coming from Latin America with chronic heart failure. Diagnosis should be confirmed by positive serology. Right bundle branch block and left anterior fascicular block on 12-lead electrocardiogram, enlarged cardiac silhouette with no pulmonary congestion on chest X-ray and left ventricular apical aneurysm on echocardiography are the distinctive features of this condition. The clinical course is poorer than that of non-Chagas heart failure; however, medical treatment is similar. Implantable cardioverter-defibrillators are useful in the primary and secondary prevention of sudden cardiac death. Cardiac resynchronisation therapy can be given to patients on optimal medical therapy and with lengthened QRS complex. Heart transplantation is the treatment of choice for patients with end-stage Chagas heart failure.

Aortic Counterpulsation Therapy in Patients with Advanced Heart Failure: Analysis of the TBRIDGE Registry

Background

The use of aortic counterpulsation therapy in advanced heart failure is controversial.

Objectives

To evaluate the hemodynamic and metabolic effects of intra-aortic balloon pump (IABP) and its impact on 30-day mortality in patients with heart failure.

Methods

Historical prospective, unicentric study to evaluate all patients treated with IABP betwen August/2008 and July/2013, included in an institutional registry named TBRIDGE (The Brazilian Registry of Intra-aortic balloon pump in Decompensated heart failure - Global Evaluation). We analyzed changes in oxygen central venous saturation (ScvO₂), arterial lactate, and use of vasoactive drugs at 48 hours after IABP insertion. The 30-day mortality was estimated by the Kaplan-Meier method and diferences in subgroups were evaluated by the Log-rank test.

Results

A total of 223 patients (mean age 49 ± 14 years) were included. Mean left ventricle ejection fraction was 24 ± 10%, and 30% of patients had Chagas disease. Compared with pre-IABP insertion, we observed an increase in ScvO₂ (50.5% vs. 65.5%, p < 0.001) and use of nitroprusside (33.6% vs. 47.5%, p < 0.001), and a decrease in lactate levels (31.4 vs. 16.7 mg/dL, p < 0.001) and use of vasopressors (36.3% vs. 25.6%, p = 0.003) after IABP insertion. Thirty-day survival was 69%, with lower mortality in Chagas disease patients compared without the disease (p = 0.008).

Conclusion

After 48 hours of use, IABP promoted changes in the use of vasoactive drugs, improved tissue perfusion. Chagas etiology was associated with lower 30-day mortality. Aortic counterpulsation therapy is an effective method of circulatory support for patients waiting for heart transplantation.

Heart transplantation: review

Heart transplantation is currently the definitive gold standard surgical approach in the treatment of refractory heart failure. However, the shortage of donors limits the achievement of a greater number of heart transplants, in which the use of mechanical circulatory support devices is increasing. With well-established indications and contraindications, as well as diagnosis and treatment of rejection through defined protocols of immunosuppression, the outcomes of heart transplantation are very favorable. Among early complications that can impact survival are primary graft failure, right ventricular dysfunction, rejection, and infections, whereas late complications include cardiac allograft vasculopathy and neoplasms. Despite the difficulties for heart transplantation, in particular, the shortage of donors and high mortality while on the waiting list, in Brazil, there is a great potential for both increasing effective donors and using circulatory assist devices, which can positively impact the number and outcomes of heart transplants.

Transplantation in the tropics: lessons on prevention and management of tropical infectious diseases

Tropical infectious diseases (IDs) remain a rare complication in transplant recipients even in tropical settings, but this topic has become increasingly important during the last decade due to multiple factors. Interestingly, non-tropical countries report most of the experiences with tropical diseases. The reported experience from non-endemic regions, however, does not always reflect the experience of endemic areas. Most of the guidelines and recommendations in the literature may not be applicable in tropical settings due to logistical difficulties, cost, and lack of proven benefit. In addition, certain post-transplant prevention measures, as prophylaxis and reducing exposure risk, are not feasible. Nonetheless, risk assessment and post-transplant management of tropical IDs in tropical areas should not be neglected, and clinicians need to have a higher clinical awareness for tropical ID occurring in this population. Herein, we review the more significant tropical ID in transplant patients, focusing on relevant experience reported by tropical settings.

Immunohistochemical quantification of inflammatory cells in endomyocardial biopsy fragments after heart transplantation: a new potential method to improve the diagnosis of rejection after heart transplantation

Inconsistencies in cardiac rejection grading systems corroborate the concept that the evaluation of inflammatory intensity and myocyte damage seems to be subjective. We studied in 36 patients the potential role of the immunohistochemical (IHC) counting of inflammatory cells in endomyocardial biopsy (EMB) as an objective tool, testing the hypothesis of correlation between the International Society for Heart and Lung Transplantation 2004 rejection and IHC counting of inflammatory cells. We observed a progressive increment in CD68+ cells/mm(2) (P = .000) and CD3+ cells/mm(2) (P = .000) with higher rejection grade. A strong correlation between the grade of cellular rejection and both CD68+ cells/mm(2) and CD3+ cells/mm(2) was obtained (P = .000). One patient with CD3+ and CD68+ cells/mm(2) above the upper limit of the 95% confidence interval for cells/mm(2) found in rejection grade 1R evolved to rejection grade 2R without treatment. In patients with 2R that did not respond to treatment the values of CD68+ or CD3+ cells were higher than the overall median values for rejection grade 2R. For diagnosis of rejection needing treatment, the CD68+ and CD3+ cells/mm(2) areas under the receiver operating characteristic curves were 0.956 and 0.934, respectively. IHC counting of mononuclear inflammatory infiltrate in EMB seems to have additive potential role in evaluation of EMB for the diagnosis and prognosis of rejection episodes.

Chagas disease in the immunosuppressed patient

This review addresses relevant aspects of Chagas disease in the immunocompromised host. Chagas disease--one of the world's most neglected diseases-has become a global public health concern. Novel transmission modalities, such as organ transplantation, evidence of parasite persistence in chronically infected individuals--with the potential for reactivation under immunosuppression--and the prolonged survival of immunosuppressed patients call for an appraisal of the disease in this particular setting. The management and outcome of solid organ transplantation in the infected recipient with special focus on heart transplantation is addressed. The guidelines for management and the outcome of the recipients of organs from infected donors are discussed, and comments on haematopoietic stem cell transplantation are included. Finally, Chagas disease in other situations of impairment of the immune system, such as HIV/AIDS and autoimmune diseases, are considered. Immunosuppression has become an increasingly frequent condition that might modify the natural history of Trypanosoma cruzi infection. A number of strategies are available for Chagas disease management in the immunosuppressed patient. First, according to recent recommendations from the health authorities in Argentina, most infected patients would benefit from being treated at diagnosis. This has not been validated for patients with different immunosuppressive disorders. A different strategy would involve treating only patients with documented reactivation (either parasitaemia or clinical manifestations). These different approaches are discussed. To reach a diagnosis of parasitaemia, monitoring is essential, either with conventional methods or with molecular techniques that are not yet available in all centres. Collaborative studies are needed to improve the level of evidence, which will allow for better guidelines.

An approach to the management of Trypanosoma cruzi infection (Chagas' disease) in immunocompromised patients

The epidemiology of Chagas disease has changed in the last decades due to migration movements, population ageing and the emergence of new transmission routes. In endemic countries, health facilities and access to healthcare are improving and T. cruzi infected patients are also benefiting from medical advances. The HIV epidemic has spread to both endemic and non-endemic areas for T. cruzi, organ transplant rates have increased recently, especially in Latin America, and other medical conditions affecting the immune system are increasing their global burden. The natural course of Chagas disease is mainly determined by the host's cellular immune response. These conditions may therefore overlap with T. cruzi infection and alter the disease's natural history which may present with atypical clinical forms and a higher associated morbidity and mortality in immunocompromised patients. The present review aims to contribute to the management of immunosuppressed patients with T. cruzi infection.