Myocardial tissue characterization in Chagas' heart disease by cardiovascular magnetic resonance

Feasibility and Role of Cardiac Magnetic Resonance in Intensive and Acute Cardiovascular Care

Cardiac magnetic resonance (CMR) is established as a key imaging modality in a wide range of cardiovascular diseases and has an emerging diagnostic and prognostic role in selected patients presenting acutely. Recent technical advancements have improved the versatility of this imaging technique, which has become quicker and more detailed in both functional and tissue characterization assessments. Information derived from this test has the potential to change clinical management, guide therapeutic decisions, and provide risk stratification. This review aims to highlight the evolving diagnostic and prognostic role of CMR in this setting, whilst also providing practical guidance on which patients can benefit the most from CMR and which information can be derived from this test that will impact clinical management.

Cardiac remodeling and inflammation detected by magnetic resonance imaging in COVID-19 survivors

Background

Concerns have been raised about cardiac inflammation in patients with long COVID-19, particularly those with myocardial injury during the acute phase of the disease. This study was conducted to examine myopericardial involvement, detected by cardiac magnetic resonance (CMR) imaging in patients hospitalized for COVID-19.

Methods

Adult patients hospitalized with COVID-19 who presented myocardial injury or increased D-dimers were enrolled in this prospective study. All patients were invited to undergo CMR imaging examination after discharge. During follow-up, patients with nonischemic myocardial or pericardial involvement detected on the first CMR imaging examination underwent second examinations. CMR imaging findings were compared with those of a control group of healthy patients with no comorbidity.

Results

Of 180 included patients, 53 underwent CMR imaging examination. The mean age was 58.4 ± 18.3 years, and 73.6 % were male. Myocardial and pericardial LGE was reported in 43.4 % and 35.8 % of patients, respectively. Nonischemic myocardial or pericardial involvement was reported in 26 (49.1 %) patients. The prevalence of pericardial LGE was associated inversely with the interval between hospital discharge and CMR. COVID-19 survivors had higher end-systolic volume indices (ESVis) and lower left-ventricular ejection fractions than did healthy controls. Seventeen patients underwent follow-up CMR imaging; the end-diastolic volume index, ESVi, and prevalence of pericardial LGE, but not that of nonischemic LGE, were reduced.

Conclusion

Among COVID-19 survivors with myocardial injury during the acute phase of the disease, the incidences of nonischemic myocardial and pericardial LGE and CMR imaging-detected signs of cardiac remodeling, partially reversed during follow-up, were high.

The Role of Multimodality Imaging in Cardiomyopathy

PURPOSE OF REVIEW

There has been increasing use of multimodality imaging in the evaluation of cardiomyopathies.

RECENT FINDINGS

Echocardiography, cardiac magnetic resonance (CMR), cardiac nuclear imaging, and cardiac computed tomography (CCT) play an important role in the diagnosis, risk stratification, and management of patients with cardiomyopathies. Echocardiography is essential in the initial assessment of suspected cardiomyopathy, but a multimodality approach can improve diagnostics and management. CMR allows for accurate measurement of volumes and function, and can easily detect unique pathologic structures. In addition, contrast imaging and parametric mapping enable the characterization of tissue features such as scar, edema, infiltration, and deposition. In non-ischemic cardiomyopathies, metabolic and molecular nuclear imaging is used to diagnose rare but life-threatening conditions such amyloidosis and sarcoidosis. There is an expanding use of CCT for planning electrophysiology procedures such as cardioversion, ablations, and device placement. Furthermore, CCT can evaluate for complications associated with advanced heart failure therapies such as cardiac transplant and mechanical support devices. Innovations in multimodality cardiac imaging should lead to increased volumes and better outcomes.

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

BACKGROUND

Sudden cardiac death (SCD) can be the first clinical event of Chagas heart disease (CHD). However, current guidelines contain no clear recommendation for early cardioverter-defibrillator implantation. Using imaging modalities, we evaluated associations among autonomic denervation, myocardial hypoperfusion, fibrosis and ventricular arrhythmia in CHD.

METHODS AND RESULTS

Twenty-nine patients with CHD and preserved left ventricular function underwent 123I-metaiodobenzylguanidine (MIBG) scintigraphy, 99mTc-methoxyisobutylisonitrile (MIBI) myocardial perfusion and cardiac magnetic resonance imaging (MRI). They were divided into arrhythmic (≥ 6 ventricular premature complexes/h and/or non-sustained ventricular tachycardia on 24-hour Holter, n = 15) and non-arrhythmic (< 6 ventricular premature complexes/h and no ventricular tachycardia; n = 14) groups. The arrhythmic group had higher denervation scores from MIBG imaging (23.2 ± 18.7 vs 5.6 ± 4.9; P < .01), hypoperfusion scores from MIBI SPECT (4.7 ± 6.8 vs 0.29 ± 0.6: P = .02), innervation/perfusion mismatch scores (18.5 ± 17.5 vs 5.4 ± 4.8; P = .01) and fibrosis by late gadolinium enhancement on MRI (14.3% ± 13.5% vs 4.0% ± 2.9%; P = .04) than the non-arrhythmic group.

CONCLUSION

These imaging parameters were associated with ventricular arrhythmia in early CHD and may enable risk stratification and the implementation of primary preventive strategies for SCD.

How Cardiac Fibrosis Assessed via T1 Mapping Is Associated with Liver Fibrosis in Patients with Non-Alcoholic Fatty Liver Disease

(1) Background: Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. Although cardiovascular and NAFLD risk factors overlap, an independent association between these conditions may exist. Hepatic and cardiac fibrosis are important markers of mortality, but the correlation between these markers in patients with NAFLD has not been well studied. Our main objective was to determine the degree of myocardial fibrosis in patients with NAFLD and its correlation with the severity of liver fibrosis. (2) Methods: In this cross-sectional study, patients with NAFLD were allocated to two groups according to the stage of liver fibrosis assessed using MRI: no or mild fibrosis (F0-F1) and significant fibrosis (F2-F4). Framingham risk scores were calculated to evaluate cardiovascular risk factors, and patients underwent multiparametric cardiac and abdominal MRIs. (3) Results: The sample comprised 44 patients (28 with no or mild liver fibrosis and 16 with significant liver fibrosis). The mean age was 57.9 ± 12 years, and 41% were men. Most patients had high cardiac risk factors and carotid disease. Relative to patients with no or mild liver fibrosis, those with significant fibrosis had a higher median calcium score (p = 0.05) and increased myocardial extracellular volume (ECV; p = 0.02). Liver fibrosis correlated with cardiac fibrosis, represented by the ECV (r = 0.49, p < 0.001). The myocardial ECV differentiated patients with and without significant liver fibrosis (AUC = 0.78). (4) Conclusion: This study showed that diffuse myocardial fibrosis is associated with liver fibrosis in patients with NAFLD.

Chagas Disease Cardiomyopathy

Chagas disease is a prominent neglected tropical disease endemic to many countries in Latin America. Cardiomyopathy is the most serious manifestation due to the severity and complications of heart failure. As a result of expanded immigration and globalization, there is an increased number of patients with Chagas cardiomyopathy who are being admitted to hospitals in the United States. It is imperative as a critical care nurse to be educated on the nature of Chagas cardiomyopathy as it differs from the more commonly seen ischemic and nonischemic forms. This article provides an overview of the clinical course, management, and treatment options of Chagas cardiomyopathy.

Detection of Early Diffuse Myocardial Fibrosis and Inflammation in Chagas Cardiomyopathy with T1 Mapping and Extracellular Volume

Purpose

To evaluate myocardial T1 mapping and extracellular volume (ECV) parameters in different stages of Chagas cardiomyopathy and determine whether they are predictive of disease severity and prognosis.

Materials and Methods

Prospectively enrolled participants (July 2013 to September 2016) underwent cine and late gadolinium enhancement (LGE) cardiac MRI and T1 mapping with a precontrast (native) or postcontrast modified Look-Locker sequence. The native T1 and ECV values were measured among subgroups that were based on disease severity (indeterminate, Chagas cardiomyopathy with preserved ejection fraction [CCpEF], Chagas cardiomyopathy with midrange ejection fraction [CCmrEF], and Chagas cardiomyopathy with reduced ejection fraction [CCrEF]). Cox proportional hazards regression and the Akaike information criterion were used to determine predictors of major cardiovascular events (cardioverter defibrillator implant, heart transplant, or death).

Results

In 107 participants (90 participants with Chagas disease [mean age ± SD, 55 years ± 11; 49 men] and 17 age- and sex-matched control participants), the left ventricular (LV) ejection fraction and the extent of focal and diffuse or interstitial fibrosis were correlated with disease severity. Participants with CCmrEF and participants with CCrEF showed significantly higher global native T1 and ECV values than participants in the indeterminate, CCpEF, and control groups (T1: 1072 msec ± 34 and 1073 msec ± 63 vs 1010 msec ± 41, 1005 msec ± 69, and 999 msec ± 46; ECV: 35.5% ± 3.6 and 35.0% ± 5.4 vs 25.3% ± 3.5, 28.2% ± 4.9, and 25.2% ± 2.2; both P < .001). Remote (LGE-negative areas) native T1 and ECV values were also higher (T1: 1056 msec ± 32 and 1071 msec ± 55 vs 1008 msec ± 41, 989 msec ± 96, and 999 msec ± 46; ECV: 30.2% ± 4.7 and 30.8% ± 7.4 vs 25.1% ± 3.5, 25.1% ± 3.7, and 25.0% ± 2.2; both P < .001). Abnormal remote ECV values (>30%) occurred in 12% of participants in the indeterminate group, which increased with disease severity. Nineteen combined outcomes were observed (median follow-up time: 43 months), and a remote native T1 value greater than 1100 msec was independently predictive of combined outcomes (hazard ratio, 12 [95% CI: 4.1, 34.2]; P < .001).

Conclusion

Myocardial native T1 and ECV values were correlated with Chagas disease severity and may serve as markers of myocardial involvement in Chagas cardiomyopathy that precede LGE and LV dysfunction.Keywords: MRI, Cardiac, Heart, Imaging Sequences, Chagas Cardiomyopathy Supplemental material is available for this article. © RSNA, 2023.

Risk Factors for Progression to Chronic Chagas Cardiomyopathy: A Systematic Review and Meta-Analysis

Approximately one-third of people with chronic Trypanosoma cruzi infection develop Chagas cardiomyopathy, which carries a poor prognosis. Accurate prediction of which individuals will go on to develop Chagas cardiomyopathy remains elusive. We performed a systematic review of literature comparing characteristics of individuals with chronic Chagas disease with or without evidence of cardiomyopathy. Studies were not excluded on the basis of language or publication date. Our review yielded a total of 311 relevant publications. We further examined the subset of 170 studies with data regarding individual age, sex, or parasite load. A meta-analysis of 106 eligible studies indicated that male sex was associated with having Chagas cardiomyopathy (Hedge's g: 1.56, 95% CI: 1.07-2.04), and a meta-analysis of 91 eligible studies indicated that older age was associated with having Chagas cardiomyopathy (Hedge's g: 0.66, 95% CI: 0.41-0.91). A meta-analysis of four eligible studies did not find an association between parasite load and disease state. This study provides the first systematic review to assess whether age, sex, and parasite load are associated with Chagas cardiomyopathy. Our findings suggest that older and male patients with Chagas disease are more likely to have cardiomyopathy, although we are unable to identify causal relationships due to the high heterogeneity and predominantly retrospective study designs in the current literature. Prospective, multidecade studies are needed to better characterize the clinical course of Chagas disease and identify risk factors for progression to Chagas cardiomyopathy.

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.

Late Gadolinium Enhancement by Cardiac Magnetic Resonance and Speckle Tracking Echocardiography in the Evaluation of Cardiac Complications in Chagas Cardiomyopathy: A Systematic Review

Background

Chagas cardiomyopathy (CC) increases cardiovascular mortality associated with congestive heart failure (CHF), ventricular arrhythmias (VA), and sudden cardiac death (SCD). Different imaging techniques have been tested to assess disease progression and cardiac risk in individuals with Chagas disease (ChD). In this systematic review, we evaluated the accuracy in detecting cardiac complications in CC patients using cardiac magnetic resonance (CMR) and speckle tracking echocardiography (STE).

Methods

A search was done on PubMed, Cochrane, and Embase for studies in humans over 18 years of age with ChD. Demographic data, research methodology, imaging parameters, and cardiac outcomes were extracted, and study quality was assessed, resulting in a narrative description.

Results

Twelve studies with 1124 patients were analyzed. One study discovered a contractility pattern by STE. Four studies assessed the identification of Early Cardiac Impairment (ECI) and VA risk, respectively, while three studies evaluated the risk of SCD. Global Longitudinal Strain (GLS) identified patients with ECI (-18.5 ± 3.4% non-fibrosis vs -14.0 ± 5.8% fibrosis, p = 0.006 and -18 ± 2% non-fibrosis vs -15 ± 2% fibrosis, p = 0.004). The amount of fibrosis > 11.78% or in two or more contiguous transmural segments were markers for VA risk. GLS and the amount of fibrosis were found to be predictors of SCD.

Conclusions

STE may be considered a screening technique for identifying the subclinical status of CHF. CMR using Late Gadolinium Enhancement (LGE) is considered a relevant parameter for stratifying patients with ChD who are at risk of SCD. Fibrosis and GLS can be used as markers to categorize patients at risk for arrhythmias.

Three and two-dimensional cardiac mechanics by speckle tracking are predictors of outcomes in chagas heart disease

Chagas disease (CD) is a neglected infectious disease associated with early mortality and substantial disability. Three-dimensional speckle tracking (3D STE) may play a role in the evaluation of CD. We aim to characterize new echocardiographic variables in patients with CD and to assess the hypothesis that 3D STE may predict outcomes. Seventy-two patients with CD were included. Clinical and conventional 2D and 3D STE analysis were performed. Patients were followed up for 60 months. Clinical events were defined as hospitalization for heart failure, complex ventricular arrhythmias, heart transplant and all-cause death. Seventy-two patients were recruited and enrolled in three groups: left ventricular ejection fraction (LVEF) < 0.40 (N = 22; reduced LVEF or rLVEF); 0.40 ≤ LVEF ≤ 0.50 (N = 10; mildly reduced LVEF or mrLVEF) and LVEF > 0.50 (N = 30; preserved LVEF or pLVEF). After a Cox model analysis, the top predictors of composite endpoints were 2D LV global longitudinal strain (GLS) ≤ − 11.3% (AUC = 0.87), 2D LV global circumferential strain (GCS) ≤  − 10.1% (AUC = 0.79), 3D LV GLS ≤ − 13% (AUC = 0.82), 3D LV area strain ≤ − 16% (AUC = 0.81) and right ventricle (RV) GLS ≤ − 17.2% (AUC = 0.78). Patients with CD and mrLVEF were morphologically similar to the rLVEF patients despite the benign evolution as the pLVEF group. RV GLS, 2D LV GLS, 2D LV GCS, 3D LV GLS, and 3D LV area strain are strong predictors of 60 months outcomes in patients with CD.

Myocardial Injury in Patients With Acute and Subacute Chagas Disease in the Brazilian Amazon Using Cardiovascular Magnetic Resonance

Background Chagas disease is a neglected tropical disease that is still considered a global health emergency. In the Amazon region, most of the reports are of acute cases that are associated with oral transmission. This study aimed to evaluate myocardial injury in patients with acute Chagas disease before and after treatment. Methods and Results We evaluated 23 patients with acute Chagas disease in 3 different stages of progression. Group 1 had 12 patients evaluated during the acute phase, at the time of diagnosis, and 1 year after treatment, and Group 2 had 11 patients in the late postacute phase who were evaluated 5.2 years on average after diagnosis and treatment. ECGs with the Selvester score, 24-hour Holter exam, and cardiovascular magnetic resonance imaging were performed. The mean age of the 23 patients was 44.3±18.9 years, and they were mostly men (15/65.24%) from Amazonas state (22/95.6%). In 69.6% (n=16) of the patients, some ECG alterations were found, the most frequent being left anterior fascicular block and ventricular repolarization. In Group 1, the 24-hour Holter exam showed atrial tachycardia in 3 (25%) patients and ventricular extrasystoles in 2 (16.7%) patients. In Group 2, 1 patient had ventricular extrasystoles. Myocardial injury was observed in 7 patients (58.3%) at the acute phase and in 5 (50%) patients at the 1-year follow-up in Group 1 and in 2 (18.2%) patients in Group 2. Conclusions This article describes, for the first time, myocardial injury shown by cardiovascular magnetic resonance imaging in a group of patients with acute Chagas disease and reveals the importance of early detection and follow-up of the cardiac impairment in these patients.

Diffuse Myocardial Fibrosis and Cardiomyocyte Diameter Are Associated With Heart Failure Symptoms in Chagas Cardiomyopathy

Background

Chronic Chagas cardiomyopathy (CCC) constitutes the most life-threatening consequence of the Trypanosoma cruzi infection. Our goal was to test in CCC the associations of the myocardial tissue phenotype with cardiac dysfunction, and heart failure (HF) severity, using cardiac magnetic resonance (CMR).

Methods

We performed a prospective observational cohort of patients with consecutive CCC with a CMR protocol, including ventricular function, myocardial T1, and late gadolinium enhancement (LGE). Extracellular volume (ECV), and intracellular water lifetime, τic, a measure of cardiomyocyte diameter, were compared to CCC disease progression, including Rassi score and New York Heart Association (NYHA) class. An exploratory prognostic analysis was performed to investigate the association of both ECV and τic with CV death.

Results

A total of 37 patients with intermediate-to-high-risk CCC were enrolled (Chagas Rassi score ≥7, mean left ventricle (LV) ejection fraction (EF) 32 ± 16%). Myocardial ECV (0.40 ± 0.07) was correlated with Rassi score (r = 0.43; P = 0.009), higher NYHA class, and LV EF (r = -0.51; P = 0.0015). τic decreased linearly with NYHA class (P = 0.007 for non-parametric test of linear trend) and showed a positive association with LV EF (r = 0.47; P = 0.004). Over a median follow-up of 734 days (range: 6-2,943 days), CV death or cardiac transplantation occurred in 10 patients. The Rassi score (heart rate [HR] = 1.3; 95% CI = [1.0, 1.8]; P = 0.028) and ECV (HR = 3.4 for 0.1 change, 95% CI = [1.1, 11.0], P = 0.039) were simultaneously associated with CV death.

Conclusion

In patients with intermediate-to-high-risk CCC, an expanded ECV and regression of cardiomyocyte diameter were associated with worsening systolic function and HF severity, respectively. The exploratory analysis indicates that ECV may have a prognostic value to identify patients with CCC at a higher risk for cardiovascular events.

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.

Myocardial oedema: pathophysiological basis and implications for the failing heart

Myocardial fluid homeostasis relies on a complex interplay between microvascular filtration, interstitial hydration, cardiomyocyte water uptake and lymphatic removal. Dysregulation of one or more of these mechanisms may result in myocardial oedema. Interstitial and intracellular fluid accumulation disrupts myocardial architecture, intercellular communication, and metabolic pathways, decreasing contractility and increasing myocardial stiffness. The widespread use of cardiac magnetic resonance enabled the identification of myocardial oedema as a clinically relevant imaging finding with prognostic implications in several types of heart failure. Furthermore, growing experimental evidence has contributed to a better understanding of the physical and molecular interactions in the microvascular barrier, myocardial interstitium and lymphatics and how they might be disrupted in heart failure. In this review, we summarize current knowledge on the factors controlling myocardial water balance in the healthy and failing heart and pinpoint the new potential therapeutic avenues.

Clinical, electrocardiographic and echocardiographic evolution of chronic Chagas disease treated with nifurtimox on prolonged follow-up in Chile: observational study

OBJECTIVES

This study aimed to describe the electrocardiographic and echocardiographic status of chronic Chagas disease (cChD) patients treated with nifurtimox.

METHODS

An observational study was performed in 146 cChD patients followed over a mean of 7.9 years.

RESULTS

Of the 146 patients, 41 (28.1%) with normal electrocardiogram (ECG) at baseline maintained this condition, 34 (23.3%) with altered ECG at baseline normalised the alterations, and 46 (31.5%) with ECG abnormalities at baseline maintained this condition [23 (15.8%) with small alterations]. Finally, 25 cases (17.1%) in indeterminate phase altered the ECG. Differences before and after follow-up (P < 0.001) were found. The percentage of beneficial treatment was different than expected by chance (Z = 4.8; P < 0.001) and the annual percentage of cases that developed ECG alterations was lower than that of a historical cohort of untreated patients (P < 0.001). An echocardiogram was performed in 68 patients with baseline ECG alterations. The ejection fraction (EF) was normal in 57 (83.8%) and abnormal in 11 (16.2%). In 38 patients with ECG abnormalities that did not progress after treatment, EF and segmental motility (SM) were normal in 31 (81.6%) and 26 (68.4%), respectively. In 17 patients with ECG abnormalities, EF and SM were normal in 15 (88.2%) and 14 (82.4%) cases, respectively.

CONCLUSION

Less progression to cardiomyopathy compared with a historical untreated cohort as well as the EF/SM results in patients with abnormal ECG that did not progress and in indeterminate cChD that altered the ECG suggests a beneficial effect of nifurtimox.

ACR Appropriateness Criteria® Nonischemic Myocardial Disease with Clinical Manifestations (Ischemic Cardiomyopathy Already Excluded)

Nonischemic cardiomyopathies encompass a broad spectrum of myocardial disorders with mechanical or electrical dysfunction without evidence of ischemia. There are five broad variants of nonischemic cardiomyopathies; hypertrophic cardiomyopathy (Variant 1), restrictive or infiltrative cardiomyopathy (Variant 2), dilated or unclassified cardiomyopathy (Variant 3), arrhythmogenic cardiomyopathy (Variant 4), and inflammatory cardiomyopathy (Variant 5). For variants 1, 3, and 4, resting transthoracic echocardiography, MRI heart function and morphology without and with contrast, and MRI heart function and morphology without contrast are the usually appropriate imaging modalities. For variants 2 and 5, resting transthoracic echocardiography and MRI heart function and morphology without and with contrast are the usually appropriate imaging modalities. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

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

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

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

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

COVID-19: Implications for People with Chagas Disease

As the global COVID-19 pandemic advances, it increasingly impacts those vulnerable populations who already bear a heavy burden of neglected tropical disease. Chagas disease (CD), a neglected parasitic infection, is of particular concern because of its potential to cause cardiac, gastrointestinal, and other complications which could increase susceptibility to COVID-19. The over one million people worldwide with chronic Chagas cardiomyopathy require special consideration because of COVID-19’s potential impact on the heart, yet the pandemic also affects treatment provision to people with acute or chronic indeterminate CD. In this document, a follow-up to the WHF-IASC Roadmap on CD, we assess the implications of coinfection with SARS-CoV-2 and Trypanosoma cruzi, the etiological agent of CD. Based on the limited evidence available, we provide preliminary guidance for testing, treatment, and management of patients affected by both diseases, while highlighting emerging healthcare access challenges and future research needs.

Cardiac magnetic resonance imaging in Chagas' disease: a parallel with electrophysiologic studies

Chagas' disease (CD), caused by the parasite Trypanosoma cruzi, is the leading cause of cardiac disability from infectious diseases in Central and South America. The disease progresses through an extended, asymptomatic form characterized by latency without clinical manifestations into a symptomatic form with cardiac and gastro-intestinal manifestations. In the terminal phase, chronic Chagas' myocarditis results in extensive myocardial fibrosis, chamber enlargement with aneurysms and ventricular tachycardia (VT). Cardiac magnetic resonance imaging (CMR) has proven useful in characterizing myocardial fibrosis (MF). Sub-epicardial and mid-wall fibrosis are less common patterns of MF in CHD than transmural scar, which resembles myocardial infarction. Commonly involved areas of MF include the left ventricular apex and basal infero-lateral wall, suggesting a role for watershed ischemia in the pathophysiology of MF. Electrophysiology studies have helped refine the relationship between MF and VT in this setting. This article reviews the patterns of MF in CHD and correlate these patterns with electrogram patterns to predict risk of ventricular arrhythmias and sudden death.

Clinical and Research Tools for the Study of Cardiovascular Effects of Cancer Therapy

The expansion of cancer therapeutics has paved the way for improved cancer-related outcomes. Cardiotoxicity from cancer therapy occurs in a small but significant subset of patients, is often poorly understood, and contributes to adverse outcomes at all stages of cancer treatment. Given the often-idiopathic occurrence of cardiotoxicity, novel strategies are needed for risk-stratification and early identification of cancer patients experiencing cardiotoxicity. Clinical and research tools extending from imaging to blood-based biomarkers and pluripotent stem cells are being explored as methods to study the cardiovascular impact of various cancer treatments. Here we provide an overview of tools currently available for evaluation of cardiotoxicity and highlight novel techniques in development aimed at understanding underlying pathophysiologic mechanisms.

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

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

New Imaging Parameters to Predict Sudden Cardiac Death in Chagas Disease

Chronic Chagas' cardiomyopathy is the most severe and frequent manifestation of Chagas disease, and has a high social and economic burden. New imaging modalities, such as strain echocardiography, nuclear medicine, computed tomography and cardiac magnetic resonance imaging, may detect the presence of myocardial fibrosis, inflammation or sympathetic denervation, three conditions associated with risk of sudden death, providing additional diagnostic and/or prognostic information. Unfortunately, despite its high mortality, there is no clear recommendation for early cardioverter-defibrillator implantation in patients with Chagas heart disease in the current guidelines. Ideally, the risk of sudden cardiac death may be evaluated in earlier stages of the disease using new image methods to allow the implementation of primary preventive strategies.

Chagas heart disease: A contemporary review

Chagas disease is caused by a parasite infection endemic of the Americas. Traditionally observed in rural areas of Latin America, current migration trends have turned Chagas disease into a global epidemic. Acute infection is rarely severe and once it resolves, some patients can develop cardiomyopathy as part of the chronic form many years later. Multiple factors related with both the host and the parasite determine the susceptibility and progression to cardiomyopathy. Current imaging techniques are able to identify cardiac autonomic denervation, perfusion abnormalities, and myocardial fibrosis at an early of stage before the development of symptoms. The prognosis of patients with Chagasic cardiomyopathy remains poor and life-threatening ventricular arrhythmias can occur at an early stage. Treatment of chronic Chagas cardiomyopathy is challenging with a great need for more studies in the field.

Improved Biomarker and Imaging Analysis for Characterizing Progressive Cardiac Fibrosis in a Mouse Model of Chronic Chagasic Cardiomyopathy

Background

Chronic chagasic cardiomyopathy (CCC), caused by Trypanosoma cruzi infection, is an important public health problem attributable to progressive cardiomyopathy in patients, for which there is no cure. Chronic chagasic cardiomyopathy is characterized by myocarditis and cardiac fibrosis, which leads to life‐threatening arrhythmogenic and circulatory abnormalities. This study aimed to investigate cardiac fibrosis progression in a mouse model of chronic chagasic cardiomyopathy.

Methods and Results

Cardiac cells infected with T cruzi produced significantly higher concentrations of transforming growth factor‐β (TGF‐β), connective tissue growth factor, endothelin‐1, and platelet‐derived growth factor‐D than noninfected controls. Female Balb/c mice infected with T cruzi were compared with naïve mice. TGF‐β genes and other TGF‐β superfamily genes, as well as connective tissue growth factor, endothelin‐1, and platelet‐derived growth factor, were upregulated in infected mouse hearts. Serum concentrations of TGF‐β, connective tissue growth factor, and platelet‐derived growth factor‐D were higher in infected mice and correlated with cardiac fibrosis. Strain analysis performed on magnetic resonance images at 111 and 140 days postinfection and echocardiography images at 212 days postinfection revealed significantly elevated left ventricular strain and cardiac fibrosis and concomitantly significantly decreased cardiac output in infected mice.

Conclusions

TGF‐β, connective tissue growth factor and platelet‐derived growth factor‐D are potentially useful biomarkers of cardiac fibrosis, as they correlate with cardiac fibrosis. Strain analysis allows for use of noninvasive methods to measure fibrosis in the chronic stages of chagasic cardiomyopathy in a mouse model. These findings can be applied as noninvasive tools to study the effects of interventions and/or therapeutics on cardiac fibrosis development when using a mouse model of chronic chagasic cardiomyopathy.

Cardiovascular Magnetic Resonance in Nonischemic Myocardial Inflammation: Expert Recommendations

This JACC Scientific Expert Panel provides consensus recommendations for an update of the cardiovascular magnetic resonance (CMR) diagnostic criteria for myocardial inflammation in patients with suspected acute or active myocardial inflammation (Lake Louise Criteria) that include options to use parametric mapping techniques. While each parameter may indicate myocardial inflammation, the authors propose that CMR provides strong evidence for myocardial inflammation, with increasing specificity, if the CMR scan demonstrates the combination of myocardial edema with other CMR markers of inflammatory myocardial injury. This is based on at least one T2-based criterion (global or regional increase of myocardial T2 relaxation time or an increased signal intensity in T2-weighted CMR images), with at least one T1-based criterion (increased myocardial T1, extracellular volume, or late gadolinium enhancement). While having both a positive T2-based marker and a T1-based marker will increase specificity for diagnosing acute myocardial inflammation, having only one (i.e., T2-based OR T1-based) marker may still support a diagnosis of acute myocardial inflammation in an appropriate clinical scenario, albeit with less specificity. The update is expected to improve the diagnostic accuracy of CMR further in detecting myocardial inflammation.

Cardiovascular Magnetic Resonance Imaging Evidence of Edema in Chronic Chagasic Cardiomyopathy

The persistence of inflammatory processes in the myocardium in varying degrees of chronic Chagas heart disease has been poorly investigated. We hypothesized that edema could occur in patients with chronic chagasic cardiomyopathy and corresponds to the persistence of inflammatory processes in the myocardium. Eighty-two Chagas disease (CD) seropositive patients (64.6% females; age = 58.9 ± 9.9) without ischemic heart disease or conditions that cause myocardial fibrosis and dilation were considered. Late gadolinium enhancement (LGE) and T2-weighted magnetic resonance imaging of edema were obtained and represented using a 17-segment model. Patients were divided into three clinical groups according to the left ventricular (LV) ejection fraction (EF) as G1 (EF > 60%; n=37), G2 (35% > EF < 60%; n=33), and G3 (EF < 35%; n=12). Comparisons were performed by the Fisher or ANOVA tests. Bonferroni post hoc, Spearman correlation, and multiple correspondence analyses were also performed. Edema was observed in 8 (9.8%) patients; 2 (5.4%) of G1, 4 (12.1%) of G2, and 2 (16.7%) of G3. It was observed at the basal inferolateral segment in 7 (87.5%) cases. LGE was observed in 48 (58.5%) patients; 16 (43.2%) of G1, 21 (63.6%) of G2, and 11 (91.7%) of G3 (p < 0.05). It was observed in the basal inferior/inferolateral/anterolateral segments in 35 (72.9%) patients and in the apical anterior/inferior/lateral and apex segments in 21 (43.7%), with midwall (85.4%; n=41), subendocardial (56.3%; n=27), subepicardial (54.2%; n=26), transmural (31.2%; n=15), and RV (1.2%; n=1) distribution. Subendocardial lesions were observed only in patients with LVEF < 35%. There was no involvement of the mid-inferolateral/anterolateral segments with an LVEF > 35% (p < 0.05). Deteriorations of the LV and RV systolic functions were positively correlated (r _s =0.69; p < 0.05) without evidence of LGE in the RV. Edema can be found in patients with chagasic cardiomyopathy in the chronic stage. In later stages of cardiac dilation with low LVEF, the LGE pattern involves subendocardium and mid locations. Deteriorations of RV and LV are positively correlated without evidence of fibrosis in the RV.

Myocardial fibrosis in chagas disease and molecules related to fibrosis

Chronic Chagas cardiomyopathy (CCC) is responsible for the disease's greater morbidity and poor prognosis. Although understanding the pathophysiology of CCC and the fundamentals of its clinical management derives from research related to other cardiomyopathies, there are peculiarities that distinguish CCC from the others. CCC is the most fibrous heart disease, and its myocardial involvement is important as it disorganizes or disrupts the extracellular matrix, creating an environment conducive to the formation of arrhythmogenic foci. It is also considered the most arrhythmogenic of the known heart diseases, giving rise to complex arrhythmias, usually associated with varying degrees of stimulus conduction disorders. The central proposal of this review is to describe a possible association between the distribution and degree of myocardial fibrosis and cardiac arrhythmogenicity in patients with Chagas cardiomyopathy, drawing attention to the importance of noninvasive biomarkers for the quantification of myocardial fibrosis.

Assessment of Cardiotoxicity of Cancer Chemotherapy: The Value of Cardiac MR Imaging

Chemotherapy is associated with cardiovascular injury, including the development of a cardiomyopathy and vascular remodeling. Cardiac magnetic resonance (CMR) is sensitive to detect not only established morphologic and functional abnormalities but also early, potentially reversible, signs of myocardial injury. It robustly detects and quantifies myocardial edema, inflammation, and focal fibrosis, as well as interstitial fibrosis and vascular remodeling. These capabilities support the role of CMR as an excellent tool for evaluating cardiotoxicity. Novel CMR markers may even enhance patient management by facilitating the early detection of reversible myocardial tissue remodeling before classic morphologic and functional changes appear.

The Value of T1 Mapping Techniques in the Assessment of Myocardial Interstitial Fibrosis

Cardiac fibrosis, characterized by net accumulation of extracellular matrix in the myocardium, is a common final pathway of heart failure. This myocardial fibrosis (MF) is not necessarily the primary cause of dysfunction; it often results from a reparative process activated in response to cardiomyocyte injury. In light of currently available treatments, late-identified MF could be definitive or irreversible, associated with worsening ventricular systolic function, abnormal cardiac remodeling, and increased ventricular stiffness and arrhythmia. T1 mapping should be used to detect incipient changes leading to myocardial damage in several clinical conditions and also in subclinical disease. This article reviews available techniques for MF detection, focusing on noninvasive quantification of diffuse fibrosis and clinical applications.

Upregulation of Cardiac IL-10 and Downregulation of IFN-γ in Balb/c IL-4-/- in Acute Chagasic Myocarditis due to Colombian Strain of Trypanosoma cruzi

Inflammatory response in Chagas disease is related to parasite and host factors. However, immune system regulation has not been fully elucidated. Thus, this study is aimed at evaluating IL-4 influence on acute phase of Trypanosoma cruzi experimental infection through dosage of cytokine levels in cardiac homogenate of infected Balb/c WT and Balb/c IL-4^−/− as well as its histopathological repercussions. For such purpose, mice were divided into two groups: an infected group with 100 forms of the Colombian strain and an uninfected group. After 21 days of infection, animals were euthanized and the blood, spleen, and heart were collected. The spleen was used to culture splenic cells in 48 h. Subsequently, cytokines TNF-α, IL-12p70, IL-10, IFN-γ, and IL-17 were measured in the blood, culture supernatant, and heart apex by ELISA. The base of the heart was used for histopathological analysis. From these analysis, infected Balb/c IL-4^−/− mice showed milder inflammatory infiltrate compared to Balb/c WT, but without changes in nest density and collagen deposition. IL-4 absence culminated in lower cardiac tissue IFN-γ production, although it did not affect TNF-α expression in situ. It also decreased TNF-α systemic production and increased IL-10, both systemically and in situ. In addition, IL-4 absence did not influence IL-17 expression. Splenocytes of IL-4-deficient mice produced higher amounts of IFN-γ, TNF-α, and IL-17 and lower amounts of IL-10. Thus, IL-4 absence in acute phase of experimental infection with T. cruzi Colombian strain reduces myocarditis due to lower IFN-γ production and greater IL-10 production in situ and this pattern is not influenced by splenocyte general repertoire.

Review of Journal of Cardiovascular Magnetic Resonance (JCMR) 2015-2016 and transition of the JCMR office to Boston

The Journal of Cardiovascular Magnetic Resonance (JCMR) is the official publication of the Society for Cardiovascular Magnetic Resonance (SCMR). In 2016, the JCMR published 93 manuscripts, including 80 research papers, 6 reviews, 5 technical notes, 1 protocol, and 1 case report. The number of manuscripts published was similar to 2015 though with a 12% increase in manuscript submissions to an all-time high of 369. This reflects a decrease in the overall acceptance rate to <25% (excluding solicited reviews). The quality of submissions to JCMR continues to be high. The 2016 JCMR Impact Factor (which is published in June 2016 by Thomson Reuters) was steady at 5.601 (vs. 5.71 for 2015; as published in June 2016), which is the second highest impact factor ever recorded for JCMR. The 2016 impact factor means that the JCMR papers that were published in 2014 and 2015 were on-average cited 5.71 times in 2016.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in the order that they are accepted with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes with previously published JCMR papers to guide continuity of thought in the journal. In addition, I have elected to open this publication with information for the readership regarding the transition of the JCMR editorial office to the Beth Israel Deaconess Medical Center, Boston and the editorial process.Though there is an author publication charge (APC) associated with open-access to cover the publisher's expenses, this format provides a much wider distribution/availability of the author's work and greater manuscript citation. For SCMR members, there is a substantial discount in the APC. I hope that you will continue to send your high quality manuscripts to JCMR for consideration. Importantly, I also ask that you consider referencing recent JCMR publications in your submissions to the JCMR and elsewhere as these contribute to our impact factor. I also thank our dedicated Associate Editors, Guest Editors, and reviewers for their many efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the leading publication in our field.

Chronic Chagas cardiomyopathy: a therapeutic challenge and future strategies

Infectious diseases are the main cause of acquired dilated cardiomyopathy. This group of disorders shares in common inflammatory cell infiltrate and myocardial remodeling. As part of its pathophysiology, there is coronary microvascular dysfunction, distinct from that observed in coronary artery disease. Chagas cardiomyopathy presents several vascular characteristics that are similar to those presented in other acquired cardiomyopathies. There is convincing evidence of the microvascular involvement and the inflammatory processes that lead to endothelial activation and ischemic damage. Current therapy for the Chagas disease is limited, and it is proposed to combine it with other pharmacological strategies that modify critical physiopathological aspects beneficial for the clinical course of the Chagas cardiomyopathy.

Association of caspase-1 polymorphisms with Chagas cardiomyopathy among individuals in Santa Cruz, Bolivia

INTRODUCTION:

Trypanosoma cruzi (Tc) infection is usually acquired in childhood in endemic areas, leading to Chagas disease, which progresses to Chagas cardiomyopathy in 20-30% of infected individuals over decades. The pathogenesis of Chagas cardiomyopathy involves the host inflammatory response to T. cruzi, in which upstream caspase-1 activation prompts the cascade of inflammatory chemokines/cytokines, cardiac remodeling, and myocardial dysfunction. The aim of the present study was to examine the association of two caspase-1 single nucleotide polymorphisms (SNPs) with cardiomyopathy.

METHODS:

We recruited infected (Tc+, n = 149) and uninfected (Tc-, n = 87) participants in a hospital in Santa Cruz, Bolivia. Cardiac status was classified (I, II, III, IV) based on Chagas cardiomyopathy-associated electrocardiogram findings and ejection fractions on echocardiogram. Genotypes were determined using Taqman probes via reverse transcription-polymerase chain reaction of peripheral blood DNA. Genotype frequencies were analyzed according to three inheritance patterns (dominant, recessive, additive) using logistic regression adjusted for age and sex.

RESULTS:

The AA allele for the caspase-1 SNP rs501192 was more frequent in Tc+ cardiomyopathy (classes II, III, IV) patients compared to those with a normal cardiac status (class I) [odds ratio (OR) = -2.18, p = 0.117]. This trend approached statistical significant considering only Tc+ patients in class I and II (OR = -2.64, p = 0.064).

CONCLUSIONS:

Caspase-1 polymorphisms may play a role in Chagas cardiomyopathy development and could serve as markers to identify individuals at higher risk for priority treatment.

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.

Cardiac Magnetic Resonance-Verified Myocardial Fibrosis in Chagas Disease: Clinical Correlates and Risk Stratification

Background

Chagas disease (CD) is an important cause of heart failure and mortality, mainly in Latin America. This study evaluated the morphological and functional characteristics of the heart as well the extent of myocardial fibrosis (MF) in patients with CD by cardiac magnetic resonance (CMR). The prognostic value of MF evaluated by myocardial-delayed enhancement (MDE) was compared with that via Rassi score.

Methods

This study assessed 39 patients divided into 2 groups: 28 asymptomatic patients as indeterminate form group (IND); and symptomatic patients as Chagas Heart Disease (CHD) group. All patients underwent CMR using the techniques of cine-MRI and MDE, and the amount of MF was compared with the Rassi score.

Results

Regarding the morphological and functional analysis, significant differences were observed between both groups (p < 0.001). Furthermore, there was a strong correlation between the extent of MF and the Rassi score (r = 0.76).

Conclusions

CMR is an important technique for evaluating patients with CD, stressing morphological and functional differences in all clinical presentations. The strong correlation with the Rassi score and the extent of MF detected by CMR emphasizes its role in the prognostic stratification of patients with CD.

Chagas disease in Europe: A review for the internist in the globalized world

Chagas disease (CD) or American trypanosomiasis identified in 1909 by Carlos Chagas, has become over the last 40years a global health concern due to the huge migration flows from Latin America to Europe, United States, Canada and Japan. In Europe, most migrants from CD-endemic areas are concentrated in Spain, Italy, France, United Kingdom and Switzerland. Pooled seroprevalence studies conducted in Europe show an overall 4.2% prevalence, with the highest infection rates observed among individuals from Bolivia (18.1%). However, in most European countries the disease is neglected with absence of screening programmes and low access to diagnosis and treatment. Physicians working in Europe should also be aware of the risk of autochthonous transmission of Trypanosoma cruzi to newborns by their infected mothers and to recipients of blood or transplanted organs from infected donors. Finally, physicians should be able to recognize and treat the most frequent and serious complications of chronic Chagas disease, namely cardiomyopathy, megacolon and megaesophagus. This review aims to highlights the problem of CD in Europe by reviewing papers published by European researchers on this argument, in order to raise the awareness of internists who are bound to increasingly encounter patients with the disease in their routine daily activities.

Imaging Diagnosis of Right Ventricle Involvement in Chagas Cardiomyopathy

Right ventricle (RV) is considered a neglected chamber in cardiology and knowledge about its role in cardiac function was mostly focused on ventricular interdependence. However, progress on the understanding of myocardium diseases primarily involving the RV led to a better comprehension of its role in health and disease. In Chagas disease (CD), there is direct evidence from both basic and clinical research of profound structural RV abnormalities. However, clinical detection of these abnormalities is hindered by technical limitations of imaging diagnostic tools. Echocardiography has been a widespread and low-cost option for the study of patients with CD but, when applied to the RV assessment, faces difficulties such as the absence of a geometrical shape to represent this cavity. More recently, the technique has evolved to a focused guided RV imaging and myocardial deformation analysis. Also, cardiac magnetic resonance (CMR) has been introduced as a gold standard method to evaluate RV cavity volumes. CMR advantages include precise quantitative analyses of both LV and RV volumes and its ability to perform myocardium tissue characterization to identify areas of scar and edema. Evolution of these cardiac diagnostic techniques opened a new path to explore the pathophysiology of RV dysfunction in CD.

Chagas' heart disease: gender differences in myocardial damage assessed by cardiovascular magnetic resonance

BACKGROUND

Since a male-related higher cardiovascular morbidity and mortality in patients with Chagas' heart disease has been reported, we aimed to investigate gender differences in myocardial damage assessed by cardiovascular magnetic resonance (CMR).

METHODS AND RESULTS

Retrospectively, 62 seropositive Chagas' heart disease patients referred to CMR (1.5 T) and with low probability of having significant coronary artery disease were included in this analysis. Amongst both sexes, there was a strong negative correlation between LV ejection fraction and myocardial fibrosis (male r = 0.64, female r = 0.73, both P < 0.001), with males showing significantly greater myocardial fibrosis (P = 0.002) and lower LV ejection fraction (P < 0.001) than females. After adjustment for potential confounders, gender remained associated with myocardial dysfunction, and 53% of the effect was mediated by myocardial fibrosis (P for mediation = 0.004). Also, the transmural pattern was more prevalent among male patients (23.7 vs. 9.9%, P < 0.001) as well as the myocardial heterogeneity or gray zone (2.2 vs. 1.3 g, P = 0.003).

CONCLUSIONS

We observed gender-related differences in myocardial damage assessed by CMR in patients with Chagas' heart disease. As myocardial fibrosis and myocardial dysfunction are associated to cardiovascular outcomes, our findings might help to understand the poorer prognosis observed in males in Chagas' disease.

Review of Journal of Cardiovascular Magnetic Resonance 2015

There were 116 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2015, which is a 14 % increase on the 102 articles published in 2014. The quality of the submissions continues to increase. The 2015 JCMR Impact Factor (which is published in June 2016) rose to 5.75 from 4.72 for 2014 (as published in June 2015), which is the highest impact factor ever recorded for JCMR. The 2015 impact factor means that the JCMR papers that were published in 2013 and 2014 were cited on average 5.75 times in 2015. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is <25 % and has been falling because the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality papers to JCMR for publication.