Early detection of left ventricular contractility abnormalities by two-dimensional speckle tracking strain in Chagas’ disease

Cardiac involvement in Chagas disease and African trypanosomiasis

Trypanosomiases are diseases caused by various species of protozoan parasite in the genus Trypanosoma, each presenting with distinct clinical manifestations and prognoses. Infections can affect multiple organs, with Trypanosoma cruzi predominantly affecting the heart and digestive system, leading to American trypanosomiasis or Chagas disease, and Trypanosoma brucei primarily causing a disease of the central nervous system known as human African trypanosomiasis or sleeping sickness. In this Review, we discuss the effects of these infections on the heart, with particular emphasis on Chagas disease, which continues to be a leading cause of cardiomyopathy in Latin America. The epidemiology of Chagas disease has changed substantially since 1990 owing to the emigration of over 30 million Latin American citizens, primarily to Europe and the USA. This movement of people has led to the global dissemination of individuals infected with T. cruzi. Therefore, cardiologists worldwide must familiarize themselves with Chagas disease and the severe, chronic manifestation - Chagas cardiomyopathy - because of the expanded prevalence of this disease beyond traditional endemic regions.

WHF Recommendations for the Use of Echocardiography in Chagas Disease

Chagas disease (ChD) represents a significant health burden in endemic regions of Latin America and is increasingly being recognized as a global health issue. The cardiac involvement in ChD, known as Chagas cardiomyopathy (ChCM), is the most severe manifestation and a leading cause of heart failure and mortality in affected individuals. Echocardiography, a non-invasive imaging modality, plays a crucial role in the diagnosis, monitoring, and risk stratification of ChCM. This consensus recommendation aims to provide guidance on the appropriate use of echocardiography in ChD. An international panel of experts, including cardiologists, infectious disease specialists, and echocardiography specialists, convened to review the available evidence and provide practical recommendations based on their collective expertise. The consensus addresses key aspects related to echocardiography in ChD, including its role in the initial evaluation, serial monitoring, and risk assessment of patients. It emphasizes the importance of standardized echocardiographic protocols, including the assessment of left ventricular function, chamber dimensions, wall motion abnormalities, valvular involvement, and the presence of ventricular aneurysm. Additionally, the consensus discusses the utility of advanced echocardiographic techniques, such as strain imaging and 3D echocardiography, in assessing myocardial mechanics and ventricular remodeling.

Estimating Echocardiographic Myocardial Strain of Left Ventricle with Deep Learning

The global longitudinal strain of the myocardial tissue has been shown to be a better indicator of cardiac pathologies in the subclinical stage than other indices, such as the ejection fraction. This article presents a new deep learning approach for strain estimation in 2D echocardiograms. The proposed method improves the performance of the state of the art without losing stability with noisy echocardiograms and achieved an average end point error of 0.14 ± 0.17 pixels in the estimation of the optical flow in the myocardium and an error of 1.34 ± 2.34 % in the estimation of the global longitudinal strain indicator when evaluated in a synthetic echocardiographic dataset. Further research will validate the proposed method by a clinical in-vivo dataset. Clinical relevance- This paper presents a method to estimate the global longitudinal strain index in noisy echocardiograms, which promises to be a better indicator of cardiac pathologies in the subclinical stage than other indices such as the ejection fraction.

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.

Longitudinal strain by speckle tracking and echocardiographic parameters as predictors of adverse cardiovascular outcomes in chronic Chagas cardiomyopathy

To analyze the prognostic value of left ventricular global longitudinal strain (LV-GLS) and other echocardiographic parameters to predict adverse outcomes in chronic Chagas cardiomyopathy (CCM). Prospective cohort study conducted in 177 consecutive patients with different CCM stages. Transthoracic echocardiography measurements were obtained following the American Society of Echocardiography recommendations. By speckle-tracking echocardiography, LV-GLS was obtained from the apical three-chamber, apical two-chamber, and apical four-chamber views. The primary composite outcome (CO) was all-cause mortality, cardiac transplantation, and a left ventricular assist device implantation. After a median follow-up of 42.3 months (Q1 = 38.6; Q3 = 52.1), the CO incidence was 22.6% (95% CI 16.7-29.5%, n = 40). The median LV-GLS value was - 13.6% (Q1 =  - 18.6%; Q3 =  - 8.5%). LVEF, LV-GLS, and E/e' ratio with cut-off points of 40%, - 9, and 8.1, respectively, were the best independent CO predictors. We combined these three echocardiographic markers and evaluated the risk of CO according to the number of altered parameters, finding a significant increase in the risk across the groups. While in the group of patients in which all these three parameters were normal, only 3.2% had the CO; those with all three abnormal parameters had an incidence of 60%. We observed a potential incremental prognostic value of LV-GLS in the multivariate model of LVEF and E/e' ratio, as the AUC increased slightly from 0.76 to 0.79, nevertheless, this difference was not statistically significant (p = 0.066). LV-GLS is an important predictor of adverse cardiovascular events in CCM, providing a potential incremental prognostic value to LVEF and E/e' ratio when analyzed using optimal cut-off points, highlighting the potential utility of multimodal echocardiographic tools for predicting adverse outcomes in CCM.

Longitudinal Speckle Tracking Strain Abnormalities in Chagas Disease: A Systematic Review and Meta-Analysis

Background: Chronic Chagas cardiomyopathy (CCM) is ranked among heart failure etiologies with the highest mortality rates. CCM is characterized by alterations in left ventricular function with a typical and unique pattern of myocardial involvement. Left ventricle longitudinal speckle tracking strain is emerging as an important additive method for evaluating left ventricular function and risk of future cardiovascular events. This systematic review aimed to characterize the left ventricle (LV) longitudinal strain by speckle tracking patterns in the different stages of Chagas disease, compared to healthy controls. Methods: Searches in Medline, EMBASE, and LILACS databases (from inception to 20 May 2021) were performed. Articles written in any language that assessed patients with Chagas disease and reported any measures derived from the left ventricular strain by speckle tracking were included. Two reviewers independently selected the studies, extracted the data, and assessed the quality of evidence. Standardized mean differences (SMD) were pooled using random-effects meta-analyses. Results: Of 1044 references, ten studies, including a total of 1222 participants (CCM: 477; indeterminate form: 444; healthy controls: 301), fulfilled the selection criteria and were included in the final analysis. Patients with CCM had a significantly higher mean global longitudinal strain (GLS) value than indeterminate form (IF) patients (SMD 1.253; 95% CI 0.53, 1.98. I² = 94%), while no significant difference was observed between IF patients and healthy controls (SMD 0.197; 95% CI −0.19, 0.59. I² = 80%). Segmental strain analyses revealed that patients with the IF form of CD had significantly worse strain values in the basal-inferoseptal (SMD 0.49; 95% CI 0.24, 0.74. I²: 24%), and mid-inferoseptal (SMD 0.28; 95% CI 0.05, 0.50. I²: 10%) segments compared to healthy controls. Conclusions: Our results suggest different levels of functional derangements in myocardial function across different stages of Chagas disease. Further research is needed to assess the prognostic role of LV longitudinal strain and other measures derived from speckle tracking in CD patients regarding progression to cardiomyopathy and clinical outcomes prediction.

Chagas heart disease: An overview of diagnosis, manifestations, treatment, and care

Chagas heart disease (CHD) affects approximately 30% of patients chronically infected with the protozoa Trypanosoma cruzi. CHD is classified into four stages of increasing severity according to electrocardiographic, echocardiographic, and clinical criteria. CHD presents with a myriad of clinical manifestations, but its main complications are sudden cardiac death, heart failure, and stroke. Importantly, CHD has a higher incidence of sudden cardiac death and stroke than most other cardiopathies, and patients with CHD complicated by heart failure have a higher mortality than patients with heart failure caused by other etiologies. Among patients with CHD, approximately 90% of deaths can be attributed to complications of Chagas disease. Sudden cardiac death is the most common cause of death (55%–60%), followed by heart failure (25%–30%) and stroke (10%–15%). The high morbimortality and the unique characteristics of CHD demand an individualized approach according to the stage of the disease and associated complications the patient presents with. Therefore, the management of CHD is challenging, and in this review, we present the most updated available data to help clinicians and cardiologists in the care of these patients. We describe the clinical manifestations, diagnosis and classification criteria, risk stratification, and approach to the different clinical aspects of CHD using diagnostic tools and pharmacological and non-pharmacological treatments.

Prospective analysis of myocardial strain through the evolution of Chagas disease in the hamster animal model

Speckle tracking echocardiography (STE) enables early diagnosis of myocardial damage by evaluating myocardial strain. We aimed to study sequential changes in structural and ventricular functional parameters during Chagas disease (CD) natural history in an animal model. 37 Syrian hamsters were inoculated intraperitoneally with Trypanosoma cruzi (Chagas) and 20 with saline (Control). Echocardiography was performed before the infection (baseline), at 1 month (acute phase), 4, 6, and 8 months (chronic phase) using Vevo 2100 (Fujifilm Inc.) ultrasound system. Left ventricular end-diastolic diameter, Left ventricular end-systolic diameter (LVESD), Left ventricular ejection fraction (LVEF), Global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain were evaluated. Tricuspid annular plane systolic excursion (TAPSE) was used to assess right ventricular function. At 8 months, animals were euthanized and LV myocardial samples were analyzed for quantitation of inflammation and fibrosis. LVEF decreased over time in Chagas group and a difference from Control was detected at 6 months (p-value of groups#time interaction = 0.005). There was a pronounced decrease in GLS, GCS and TAPSE in Chagas group (p-value of groups#time interaction = 0.003 for GLS, < 0.001 for GCS and < 0.009 for TAPSE vs Control) since the first month. LVESD, LVEF and GLS were significantly correlated to the number of inflammatory cells (r = 0.41, p = 0.046; r = − 0.42, p = 0.042; r = 0.41, p = 0.047) but not to fibrosis. In the Syrian hamster model of CD STE parameters (GLS and GCS) showed an early decrease. Changes in LVEF, LVESD, and GLS were correlated to myocardial inflammation but not to fibrosis.

Defining the reference range for right ventricular systolic strain by echocardiography in healthy subjects: A meta-analysis

BACKGROUND

Right ventricular (RV) systolic strain has recently demonstrated prognostic value in various cardiovascular diseases. Despite this, the reference range including the lower limit of normal (LLN) and factors associated with RV strain measurements are not well-established. This meta-analysis aimed to determine the mean and LLN of two- (2D) and three-dimensional (3D) right ventricular global (RVGLS), free wall (RVFWLS) and interventricular septal wall (IVSLS) longitudinal strains in healthy individuals and factors that affect strain measurements.

METHODS

In this meta-analysis, Pubmed, Embase and Cochrane databases were searched until 31 July 2020 for eligible studies reporting RVGLS, RVFWLS and/or IVSLS in at least 30 healthy subjects. We pooled the means and LLNs of RV strains by two- (2D) and three- (3D) dimensional echocardiography, and performed meta-regression analyses.

RESULTS

From 788 articles screened, 45 eligible studies totaling 4439 healthy subjects were eligible for analysis. Pooled means and LLNs with 95% confidence intervals for 2D- RV strains were RVGLS -23.4% (-24.2%, -22.6%) and -16.4% (-17.3%, -15.5%) in 27 studies; RVFWLS -26.9% (-28.0%, -25.9%) and -18.0% (-19.2%, -16.9%) in 32 studies; and IVSLS -20.4% (-22.0%, -18.9%) and -11.5% (-13.6%, -9.6%) in 10 studies, and similar results for 3D- RV strains. Right ventricular fractional area change and vendor software were associated with 2D-RVGLS and RVFWLS means and LLNs.

CONCLUSION

We reported the pooled means and LLNs of RV systolic strains in healthy subjects, to define thresholds for abnormal, borderline and normal strains. Important factors associated with RV systolic strains include right ventricular fractional area change and vendor software.

Effects of Different Systolic Blood Pressure Targets on Myocardial Function: A One-Year Follow-Up in Geriatric Hypertension

Background

A lower systolic blood pressure (SBP) target reduces major cardiovascular events and mortality from any cause of geriatric hypertension. However, the effect of different SBP targets on myocardial function remains unclear. This study aimed to determine changes in left ventricular (LV) strain in older hypertensive patients after 1 year of different SBP goals, and to evaluate its effects on myocardial mechanics in this population.

Methods

We studied 313 hypertensive adults aged 60 years or older after 1 year of the Systolic Blood Pressure Intervention Trial. They were divided into the intensive group (target SBP: 110–130 mmHg) and the standard group (target SBP: 130–150 mmHg). All participants underwent echocardiography within 1 week after enrollment and 1 year after participating in the study. Global longitudinal strain (GLS) of the LV (endocardial, middle, and epicardial layer: GLS-end, GLS-mid, and GLS-epi, respectively) and the improvement of GLS at 1 year (ΔGLS-end, ΔGLS-mid, and ΔGLS-epi) were measured.

Results

At 1 year, GLS-end in the intensive group was slightly improved compared with that before the trial (−23.78%±3.10% vs −22.58%±3.11%, P<0.05). The ΔGLS-end and ΔGLS-mid in the intensive group were higher than those in the standard group (1.20±0.23 vs 0.58±0.59% and 0.70±0.21 vs 0.52±0.17, P<0.05). Moreover, SBP at 1 year and an angiotensin II type 1 receptor antagonist were independent factors that affected ΔGLS-end (β= −0.005, P=0.004; β= 0.080, P<0.001, respectively).

Conclusion

These trial results suggest that a lower SBP target can slightly improve myocardial function in older hypertensive patients at 1 year.

Feasibility and reference intervals assessed by conventional and speckle-tracking echocardiography in normal hamsters

OBJECTIVES

This study aimed to determine feasibility, reference intervals, and reproducibility of left ventricular ejection fraction (LVEF) and speckle-tracking echocardiography (STE) in adult Syrian hamsters.

BACKGROUND

Syrian hamster is an experimental model for several heart diseases. Echocardiography allows the evaluation of structure and function with bidimensional conventional techniques and STE. However, there is no data regarding reference values for bidimensional LVEF and myocardial strain in hamsters.

METHODS

A total of 135 female Syrian hamsters were anesthetized and studied with a small animal dedicated echocardiography system. Echocardiography measurements were obtained from M-mode and B-mode images. Feasibility and 95% reference intervals were obtained for LVEF using three different approaches: LVEF_Teichholz (from M-mode linear measurements), LVEF_BMode (from area-length method), and LVEF_ STE (from strain), and for global longitudinal (GLS), circumferential (GCS), and radial (GRS) endocardial strain. Reproducibility was assessed as intra-class correlation coefficients.

RESULTS

Feasibility of LVEF and endocardial strain was high (95% in FEVE_Teichholz, 93% in the LVEF_BMode, 84% in the LVEF_STE, 84% from PSLAX, and 80% from PSSAX). Values of LVEF_Teichholz were significantly higher than values of LVEF_BMode, and LVEF_STE-derived methods (59.0 ± 5.8, 53.8 ± 4.7, 46.3 ± 5.7, p < 0.0001). The 95% reference intervals for GLS, GCS, and GRS were respectively -13.6(-7.5;-20.4)%, -20.5 ± 3.1%, and + 34,7 ± 7.0%. Intra-class correlation coefficients were 0.49 - 0.91 for LVEF measurements, 0.73 - 0.92 for STE, with better results for LVEF_Teichholz and GLS.

CONCLUSIONS

Evaluation of LVEF by several methods and STE parameters is feasible in hamsters. Reference intervals for LVEF and STE obtained for this experimental animal model can be applied at future research.

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.

Speckle tracking echocardiography in the indeterminate form of Chagas disease

BACKGROUND

Chagas disease is one of the most common diseases in Latin-America, and cardiac involvement is a significant cause of death. Assessment of myocardial strain may detect early myocardial damage.

OBJECTIVES

To determine differences in longitudinal strain using speckle tracking to assess regional and global left ventricular function in patients with the indeterminate form of Chagas disease, in comparison with a control group.

METHODS

This is a retrospective matched case-control study, conducted in a single center. We evaluated 45 adult patients with Chagas disease, diagnosed with 2 serological methods, without evidence of cardiac involvement, who were compared with 45 healthy control subjects, who were sex- and age-matched. All patients underwent Doppler echocardiography and longitudinal strain with speckle tracking.

RESULTS

Median age was 59 years, and 60% were female. Echocardiographic parameters were similar in patients with Chagas and control subjects. In patients with Chagas, global strain differed significantly from that of control subjects (-17 vs -20.3, P < .001). Segmental strain showed 7 abnormal segments in patients with Chagas (P < .05).

CONCLUSIONS

In patients with the indeterminate form of Chagas disease, global and segmental longitudinal peak systolic strain is reduced compared with healthy subjects, thus suggesting that it could be a sensitive technique to detect early myocardial damage. These findings could provide useful information regarding the pathophysiology of cardiac involvement and understand whether they might have prognostic usefulness or help develop strategies to modify the course and prognosis of patients with Chagas disease. A longitudinal prospective study would be necessary to validate our findings.

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.

Echocardiographic parameters, speckle tracking, and brain natriuretic peptide levels as indicators of progression of indeterminate stage to Chagas cardiomyopathy

BACKGROUND

Chronic Chagas cardiomyopathy (CCM) is characterized by a unique type of cardiac involvement. Few studies have characterized echocardiographic (Echo) transitions from the indeterminate Chagas disease (ChD) form to CCM. The objective of this study was to identify the best cutoffs in multiple Echo parameters, speckle tracking, and N-terminal pro B-type natriuretic peptide (NT-proBNP) to distinguish patients without CCM (stage A) vs patients with myocardial involvement (stages B, C, or D).

METHODS

Cross-sectional study conducted in 273 consecutive patients with different CCM stages. Echo parameters, NT-proBNP, and other clinical variables were measured. Logistic regression models (dichotomized in stage A versus B, C, and D) adjusted for age, sex, body mass index, and NT-proBNP were performed.

RESULTS

Left ventricular global longitudinal strain (LV-GLS), mitral flow E velocity, LV mass index, and NT-proBNP identified early changes that differentiated stages A vs B, C, and D. The LV-GLS with a cutoff -20.5% showed the highest performance (AUC 92.99%; accuracy 84.56% and negative predictive value (NPV) 88.82%), which improved when it was additionally adjusted by NT-proBNP with a cutoff -20.0% (AUC 94.30%; accuracy 88.42% and NPV 93.55%).

CONCLUSIONS

Our findings suggest that Echo parameters and NT-proBNP may be used as diagnostic variables in detecting the onset of myocardial alterations in patients with the indeterminate stage of ChD. LV-GLS was the more accurate measurement regarding stage A differentiation from the stages B, C, and D. Prospective longitudinal studies are needed to validate these findings.

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.

Speckle tracking echocardiographic deformation indices in Chagas and idiopathic dilated cardiomyopathy: Incremental prognostic value of longitudinal strain

Background

Chagas cardiomyopathy (CDC) is associated with a poor prognosis compared to other cardiomyopathies. Speckle tracking echocardiography (STE), which provides direct assessment of myocardial fiber deformation, may be useful in predicting prognosis.

Objective

This study assessed STE in CDC and compared with idiopathic cardiomyopathy (IDC), and also examined the incremental prognostic information of STE over left ventricular ejection fraction (LVEF) in these patients.

Methods

We enrolled 112 patients, age of 56.7 ± 11.8 years, 81 with CDC and 31 with IDC. STE indices were obtained at baseline in all patients. The endpoint was a composite of death, hospitalization for heart failure, or need for heart transplantation.

Results

Patients with IDC had worse LV systolic function compared to CDC, with LVEF of 34.5% vs 41.3%, p = 0.004, respectively. After adjustment for LVEF, there were no differences in STE values between CDC and IDC. During a median follow-up of 18.2 months (range, 11 to 22), 26 patients met the composite end point (24%). LV longitudinal strain was a strong predictor of adverse events, incremental to LVEF and E/e' ratio (HR 1.463, 95% CI 1.130–1.894; p = 0.004). The risk of cardiac events increased significantly in patients with GLS > - 12% (log-rank p = 0.035).

Conclusions

STE indices were abnormal in patients with dilated cardiomyopathy, without differences between CDC and IDC. LV longitudinal strain was a powerful predictor of outcome, adding prognostic information beyond that provided by LVEF and E/e' ratio.

Chagas Disease and Heart Failure: An Expanding Issue Worldwide

Chagas disease, originally a South American endemic health problem, is expanding worldwide because of people migration. Its main impact is on the cardiovascular system, producing myocardial damage that frequently results in heart failure. Pathogenic pathways are mainly related to inmunoinflamatory reactions in the myocardium and, less frequently, in the gastrointestinal tract. The heart usually shows fibrosis, producing dilatation and damage of the electrogenic cardiac system. These changes result in cardiomyopathy with heart failure and frequent cardiac arrhythmias and heart blocks. Diagnosis of the disease must include a lab test to detect the parasite or its immune reactions and the usual techniques to evaluate cardiac function. Therapeutic management of Chagas heart failure does not differ significantly from the most common treatment for dilated cardiomyopathy, with special focus on arrhythmias and several degrees of heart block. Heart transplantation is reserved for end-stage cases. Major international scientific organisations are delivering recommendations for prevention and early diagnosis. This article provides an analysis of epidemiology, prevention, treatment and the relationship between Chagas disease and heart failure.

Elevated IL-17 levels and echocardiographic signs of preserved myocardial function in benznidazole-treated individuals with chronic Chagas' disease

BACKGROUND

The immunological and clinical impact of trypanocidal treatment in chronic Chagas' disease (CCD) is unclear.

METHODOLOGY AND FINDINGS

Several cytokines were measured in plasma of 66 patients with CCD. Thirty-three patients had been previously treated with benznidazole and 33 had never been treated. The treated group exhibited higher levels of IL-17 (median 142.45×1.22pg/ml, P=0.025), which was the only one significantly associated with Bz treatment, especially after adjusting for time of disease and NYHA class (P=0.024; OR 1.006, 95% CI 1.001-1.010). Compared to untreated patients, the treated group exhibited higher median values of mitral annular E' lateral (13.0×10.0cm/s, P=0.038), S' infero-lateral (8.9×7.6cm/s, P=0.013), S' septal (8.5×7.4cm/s, P=0.034), mean S' (9.0×7.9cm/s, P=0.013) and tricuspid annular S' (13.3×11.1cm/s, P=0.001) and lower values of E/E' septal (7.2×9.5cm/s, P=0.049). After adjustment for time of disease and NYHA class, S' infero-lateral (P=0.031), mean S' (P=0.049) and S' tricuspid (P=0.024) persisted as significantly associated with treatment.

CONCLUSION

The present findings suggest that the group of CCD patients treated with Bz displayed increased plasma levels of IL-17 and preserved myocardial function, reinforcing the idea that Bz treatment may be beneficial.

Effects of Trypanocidal Treatment on Echocardiographic Parameters in Chagas Cardiomyopathy and Prognostic Value of Wall Motion Score Index: A BENEFIT Trial Echocardiographic Substudy

BACKGROUND

Serial echocardiographic studies in chronic Chagas cardiomyopathy are scarce. The aims of this study were to evaluate whether therapy with benznidazole modifies the progression of cardiac impairment and to identify baseline echocardiographic parameters related to prognosis.

METHODS

A prospective substudy was conducted in 1,508 patients with chronic Chagas cardiomyopathy randomized to benznidazole or placebo, who underwent two-dimensional echocardiography at enrollment, 2 years, and final follow-up (5.4 years). Left ventricular (LV) ejection fraction, LV wall motion score index (WMSI), indexed left atrial volume, and chamber dimensions were collected and correlated to all-cause death and a composite hard outcome using univariate and multivariate analyses.

RESULTS

At enrollment, most patients had normal chamber dimensions, and 70.5% had preserved LV ejection fractions. During follow-up, all chamber dimensions increased similarly in both treatment arms. LV ejection fraction was comparably reduced (55.7 ± 12.7% to 52.1 ± 14.6% vs 56.3 ± 12.7% to 52.8 ± 14.1%) and LV WMSI similarly increased (1.31 ± 0.41 to 1.49 ± 0.03 and 1.27 ± 0.38 to 1.51 ± 0.03) for the benznidazole and placebo groups, respectively (P > .05). A higher baseline LV WMSI was identified in subjects who died compared with those alive at final echocardiography (1.76 ± 0.517 vs 1.271 ± 0.393, P < .0001). There was a significant (P < .0001) graded increase in the risk for the composite outcome with worsening LV WMSI (hazard ratios, 2.27 [95% CI, 1.69-3.06] and 6.42 [95% CI, 4.94-8.33]) and also of death (hazard ratios, 2.45 [95% CI, 1.62-3.71] and 8.99 [95% CI, 6.3-12.82]) for 1 < LV WMSI < 1.5 and LV WMSI > 1.5, respectively. Both LV WMSI and indexed left atrial volume remained independent predictors in multivariate analysis.

CONCLUSIONS

Trypanocidal treatment had no effect on echocardiographic progression of chronic Chagas cardiomyopathy over 5.4 years. Despite normal global LV systolic function, regional wall motion abnormalities and indexed left atrial volume identified patients at higher risk for hard adverse clinical outcomes.

Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement From the American Heart Association

Background:

Chagas disease, resulting from the protozoan Trypanosoma cruzi , is an important cause of heart failure, stroke, arrhythmia, and sudden death. Traditionally regarded as a tropical disease found only in Central America and South America, Chagas disease now affects at least 300 000 residents of the United States and is growing in prevalence in other traditionally nonendemic areas. Healthcare providers and health systems outside of Latin America need to be equipped to recognize, diagnose, and treat Chagas disease and to prevent further disease transmission.

Methods and Results:

The American Heart Association and the Inter-American Society of Cardiology commissioned this statement to increase global awareness among providers who may encounter patients with Chagas disease outside of traditionally endemic environments. In this document, we summarize the most updated information on diagnosis, screening, and treatment of T cruzi infection, focusing primarily on its cardiovascular aspects. This document also provides quick reference tables, highlighting salient considerations for a patient with suspected or confirmed Chagas disease.

Conclusions:

This statement provides a broad summary of current knowledge and practice in the diagnosis and management of Chagas cardiomyopathy. It is our intent that this document will serve to increase the recognition of Chagas cardiomyopathy in low-prevalence areas and to improve care for patients with Chagas heart disease around the world.

Multimodality imaging evaluation of Chagas disease: an expert consensus of Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI)

Aims

To develop a document by Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI) to review and summarize the most recent evidences about the non-invasive assessment of patients with Chagas disease, with the intent to set up a framework for standardized cardiovascular imaging to assess cardiovascular morphologic and functional disturbances, as well as to guide the subsequent process of clinical decision-making.

Methods and results

Chagas disease remains one of the most prevalent infectious diseases in Latin America, and has become a health problem in non-endemic countries. Dilated cardiomyopathy is the most severe manifestation of Chagas disease, which causes substantial disability and early mortality in the socially most productive population leading to a significant economical burden. Prompt and correct diagnosis of Chagas disease requires specialized clinical expertise to recognize the unique features of this disease. The appropriate and efficient use of cardiac imaging is pivotal for diagnosing the cardiac involvement in Chagas disease, to stage the disease, assess patients' prognosis and address management. Echocardiography is the most common imaging modality used to assess, and follow-up patients with Chagas disease. The presence of echocardiographic abnormalities is of utmost importance, since it allows to stage patients according to disease progression. In early stages of cardiac involvement, echocardiography may demonstrate segmental left ventricuar wall motion abnormalities, mainly in the basal segments of inferior, inferolateral walls, and the apex, which cannot be attributed to obstructive coronary artery arteries. The prevalence of segmental wall motion abnormalities varies according to the stage of the disease, reaching about 50% in patients with left ventricular dilatation and dysfunction. Speckle tracking echocardiography allows a more precise and quantitative measurement of the regional myocardial function. Since segmental wall motion abnormalities are frequent in Chagas disease, speckle tracking echocardiography may have an important clinical application in these patients, particularly in the indeterminate forms when abnormalities are more subtle. Speckle tracking echocardiography can also quantify the heterogeneity of systolic contraction, which is associated with the risk of arrhythmic events. Three-dimensional (3D) echocardiography is superior to conventional two-dimensional (2D) echocardiography for assessing more accurately the left ventricular apex and thus to detect apical aneurysms and thrombus in patients in whom ventricular foreshortening is suspected by 2D echocardiography. In addition, 3D echocardiography is more accurate than 2D Simpson s biplane rule for assessing left ventricular volumes and function in patients with significant wall motion abnormalities, including aneurysms with distorted ventricular geometry. Contrast echocardiography has the advantage to enhancement of left ventricular endocardial border, allowing for more accurate detection of ventricular aneurysms and thrombus in Chagas disease. Diastolic dysfunction is an important hallmark of Chagas disease even in its early phases. In general, left ventricular diastolic and systolic dysfunction coexist and isolated diastolic dysfunction is uncommon but may be present in patients with the indeterminate form. Right ventricular dysfunction may be detected early in the disease course, but in general, the clinical manifestations occur late at advanced stages of Chagas cardiomyopathy. Several echocardiographic parameters have been used to assess right ventricular function in Chagas disease, including qualitative evaluation, myocardial performance index, tissue Doppler imaging, tricuspid annular plane systolic excursion, and speckle tracking strain. Cardiac magnetic resonance (CMR) is useful to assess global and regional left ventricular function in patients with Chagas diseases. Myocardial fibrosis is a striking feature of Chagas cardiomyopathy and late gadolinium enhancement (LGE) is used to detect and quantify the extension of myocardial fibrosis. Myocardial fibrosis might have a role in risk stratification of patients with Chagas disease. Limited data are available regarding right ventricular function assessed by CMR in Chagas disease. Radionuclide ventriculography is used for global biventricular function assessment in patients with suspected or definite cardiac involvement in Chagas disease with suboptimal acoustic window and contraindication to CMR. Myocardial perfusion scintigraphy may improve risk stratification to define cardiac involvement in Chagas disease, especially in the patients with devices who cannot be submitted to CMR and in the clinical setting of Chagas patients whose main complaint is atypical chest pain. Detection of reversible ischemic defects predicts further deterioration of left ventricular systolic function and helps to avoid unnecessary cardiac catheterization and coronary angiography.

Conclusion

Cardiac imaging is crucial to detect the cardiac involvement in patients with Chagas disease, stage the disease and stratify patient risk and address management. Unfortunately, most patients live in regions with limited access to imaging methods and point-of-care, simplified protocols, could improve the access of these remote populations to important information that could impact in the clinical management of the disease. Therefore, there are many fields for further research in cardiac imaging in Chagas disease. How to better provide an earlier diagnosis of cardiac involvement and improve patients risk stratification remains to be addressed using different images modalities.

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.

Evaluation of Right Ventricular Systolic Function in Chagas Disease Using Cardiac Magnetic Resonance Imaging

BACKGROUND

Right ventricular (RV) impairment is postulated to be responsible for prominent systemic congestion in Chagas disease. However, occurrence of primary RV dysfunction in Chagas disease remains controversial. We aimed to study RV systolic function in patients with Chagas disease using cardiac magnetic resonance.

METHODS AND RESULTS

This cross-sectional study included 158 individuals with chronic Chagas disease who underwent cardiac magnetic resonance. RV systolic dysfunction was defined as reduced RV ejection fraction based on predefined cutoffs accounting for age and sex. Multivariable logistic regression was used to verify the relationship of RV systolic dysfunction with age, sex, functional class, use of medications for heart failure, atrial fibrillation, and left ventricular systolic dysfunction. Mean age was 54±13 years, 51.2% men. RV systolic dysfunction was identified in 58 (37%) individuals. Although usually associated with reduced left ventricular ejection fraction, isolated RV systolic dysfunction was found in 7 (4.4%) patients, 2 of them in early stages of Chagas disease. Presence of RV dysfunction was not significantly different in patients with indeterminate/digestive form of Chagas disease (35.7%) compared with those with Chagas cardiomyopathy (36.8%) (P=1.000).

CONCLUSIONS

In chronic Chagas disease, RV systolic dysfunction is more commonly associated with left ventricular systolic dysfunction, although isolated and early RV dysfunction can also be identified.

Indeterminate form of Chagas disease: is left ventricular torsional mechanics a clue to subclinical myocardial abnormalities?

BACKGROUND

Chagas disease (CD) is highly endemic in Latin America, and has been emerging in developed countries. Early diagnosis of left ventricular (LV) systolic dysfunction, routinely done by echocardiography, is crucial for therapy. Speckle tracking echocardiography allows determination of LV segmental rotations, twist/torsion, and this analysis may disclose an unapparent myocardial contractile deficit in initial stages of CD. Therefore, this study aimed to highlight a possible unapparent myocardial contractile deficit in CD indeterminate form (IF) by a comprehensive torsional mechanics analysis.

METHODS

Patients with CDIF diagnosis, initial chagasic cardiomyopathy (CCMP characterized by ECG abnormalities and LVEF > 0.55), and normal controls were prospectively enrolled, and underwent conventional echocardiogram with images acquisition for STE offline analysis. Target parameters were basal and apical rotations, and calculation of twist and torsion.

RESULTS

A total of 42 patients were included (CDIF, eight; CCMP, 13; and 21 controls). Chagasic patients had a mean age of 55 years, five (24 %) men, and controls, 50 years, seven (33 %) men. Torsional mechanics analyzes resulted in no significant difference in all parameters studied between groups. Twist in CDIF was 20.8° ± 6.5°; CCMP, 19.0° ± 3.5° and controls, 19.7° ± 3.7° (p = 0.67). Torsion in CDIF was 2.6° ± 0.8°; CCMP, 2.4° ± 0.6° and controls, 2.4° ± 0.5° (p = 0.63).

CONCLUSIONS

Patients with Chagas disease have no abnormalities in torsional mechanics during its indeterminate and initial cardiomyopathy stages.

Comprehensive left ventricular mechanics analysis by speckle tracking echocardiography in Chagas disease

BACKGROUND

Chagas disease (CD) is a frequent cause of dilated cardiomyopathy (CMP) in developing countries, leading to clinical heart failure and worse prognosis. Therefore, the development and evolution of this CMP has always been a major topic in numbers of previous studies. A comprehensive echocardiographic study of left ventricular (LV) mechanics, fully assessing myocardial contraction, has never been done before. This could help characterize and improve the understanding of the evolution of this prevalent CMP.

METHODS

A total of 47 chagasic and 84 control patients were included in this study and allocated in groups according to LV ejection fraction. 2D-Echocardiogram was acquired for LV mechanics analysis by speckle tracking echocardiography.

RESULTS

Mean age of chagasic individuals was 55y and 16 (34 %) were men. Significant difference was found in global longitudinal velocity analysis, with lower values in indeterminate form. In the group with severe systolic dysfunction, a paradoxical increase in longitudinal and apical radial displacements were demonstrated. In parallel, segmental analyzes highlighted lower values of radial displacement, strain and strain rate into inferior and inferolateral walls, with increase of these values in septal and anterior walls.

CONCLUSION

Chagasic CMP has a vicarious pattern of contraction in the course of its evolution, defined by reduced displacement and strain into inferior and posterior walls with paradoxical increase in septal and anterior segments. Also, lower longitudinal velocities were demonstrated in CD indeterminate form, which may indicate an incipient myocardial injury.

The importance of speckle tracking echocardiography in the early detection of left ventricular dysfunction in patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterized by hormonal and metabolic abnormalities and is thought to increase a risk for cardiovascular diseases. In this study we use speckle tracking echocardiography (STE) to evaluate left ventricular (LV) dysfunction in the early period of the disease. We enrolled 31 patients with PCOS and 32 healthy volunteers as a control group. The participants' ages ranged between 18 and 40 years. PCOS was diagnosed according to the Rotterdam criteria. LV strain (LS) and strain rate (SR) were evaluated using apical two-chamber (2C), three-chamber (3C), and four-chamber (4C) imaging. Global LS and SR were calculated as average of three apical views. The waist-to-hip ratio, homeostasis model assessment-insulin resistance (HOMA-IR), and fasting insulin and triglyceride levels were higher in the PCOS group than in the controls (p=0.001, p=0.001, p=0.001, and p=0.005, respectively). In the PCOS group, the mitral A wave, deceleration time (DT), and isovolumetric relaxation time (IVRT) were significantly higher than in the controls (all p<0.05). The LV global longitudinal strain (GLS) and global longitudinal SR systolic (GLSRS) were significantly lower in the PCOS patient group (both p= 0.001). There were strong negative correlations between GLS and both fasting insulin (r=-0.64) and DT (r=-0.62) (both p<0.05). The study demonstrated that PCOS patients had decreased LV function using STE. Therefore, STE imaging appears to be useful for the early detection of subclinical LV dysfunction in patients with PCOS.