Impaired Coronary Flow Reserve in Patients with Indeterminate Form of Chagas’ Disease

Arrhythmogenic Manifestations of Chagas Disease: Perspectives From the Bench to Bedside

Chagas cardiomyopathy caused by infection with the intracellular parasite Trypanosoma cruzi is the most common and severe expression of human Chagas disease. Heart failure, systemic and pulmonary thromboembolism, arrhythmia, and sudden cardiac death are the principal clinical manifestations of Chagas cardiomyopathy. Ventricular arrhythmias contribute significantly to morbidity and mortality and are the major cause of sudden cardiac death. Significant gaps still exist in the understanding of the pathogenesis mechanisms underlying the arrhythmogenic manifestations of Chagas cardiomyopathy. This article will review the data from experimental studies and translate those findings to draw hypotheses about clinical observations. Human- and animal-based studies at molecular, cellular, tissue, and organ levels suggest 5 main pillars of remodeling caused by the interaction of host and parasite: immunologic, electrical, autonomic, microvascular, and contractile. Integrating these 5 remodeling processes will bring insights into the current knowledge in the field, highlighting some key features for future management of this arrhythmogenic disease.

Current vision of a disease with high mortality that is progressively dispersing throughout the world: Chagasic heart disease

The sympathetic denervation studies and the studies of microvascular involvement are the most important tools for early detection of Chagas heart disease. Especially the 123I-123I-MIBGSPECT or 11C-meta-hydroxyephedrine-PET studies since everything starts from sympathetic denervation. Also it is advisable to insist on the assessment of other parameters of early involvement of left ventricular systolic function to understand the importance of the additional information provided by the analysis of the parameters of ventricular remodeling, synchrony, and GLS in patients with normal left ventricular ejection fraction and in the absence of ventricular dilatation for early detection of myocardial dysfunction.

Aspirin plus verapamil relieves angina and perfusion abnormalities in patients with coronary microvascular dysfunction and Chagas disease: a pilot non-randomized study

INTRODUCTION

Most patients with chronic cardiomyopathy of Chagas disease (CCCD) harbor a secondary cause of coronary microvascular dysfunction (CMD), for which there is no evidence-based therapy. We evaluated the impact of verapamil plus aspirin on symptoms and perfusion abnormalities in patients with CCCD and CMD.

METHODS

Consecutive patients with angina pectoris, who had neither coronary artery obstructions nor moderate-severe left ventricular dysfunction (left ventricular ejection fraction > 40%) despite showing wall motion abnormalities on ventriculography, were referred for invasive angiography and tested for Chagas disease. Thirty-two patients with confirmed CCCD and ischemia on stress-rest SPECT myocardial perfusion scintigraphy (MPS) were included. Clinical evaluation, quality of life (EQ-5D/ Seattle Angina Questionnaire), and MPS were assessed before and after 3 months of treatment with oral verapamil plus aspirin (n=26) or placebo (n=6).

RESULTS

The mean patient age was 64 years, and 18 (56%) were female. The ischemic index summed difference score (SDS) in MPS was significantly reduced by 55.6% after aspirin+verapamil treatment. A decrease in SDS was observed in 20 (77%) participants, and in 10 participants, no more ischemia could be detected. Enhancements in quality of life were also detected. No change in symptoms or MPS was observed in the placebo group.

CONCLUSIONS

This low-cost 3-month treatment for patients diagnosed with CCCD and CMD was safe and resulted in a 55.6% reduction in ischemic burden, symptomatic improvement, and better quality of life.

Chagas Cardiomyopathy as the Etiology of Suspected Coronary Microvascular Disease. A Comparison Study with Suspected Coronary Microvascular Disease of Other Etiologies

BACKGROUND

Chagas disease (CD) as neglected secondary form of suspected coronary microvascular dysfunction (CMD).

OBJECTIVES

Comparison of patients with CMD related to CD (CMD-CE) versus patients with CMD caused by other etiologies (CMD-OE).

METHODS

Of 1292 stable patients referred for invasive coronary angiography to elucidate the hemodynamic pattern and the cause of angina as a cardinal symptom in their medical history, 247 presented normal epicardial coronary arteries and 101 were included after strict exclusion criteria. Of those, 15 had suspected CMD-CE, and their clinical, hemodynamic, angiographic and scintigraphic characteristics were compared to those of the other 86 patients with suspected CDM-OE. Level of significance for all comparisons was p < 0.05.

RESULTS

Patients with suspected CMD-CE showed most anthropometric, clinical, angiographic hemodynamic and myocardial perfusion abnormalities that were statistically similar to those detected in the remaining 86 patients with suspected CMD-OE. LV diastolic dysfunction, expressed by elevated LV end-diastolic pressure was equally found in both groups. However, as compared to the group of CMD-OE the group with CMD-CE exhibited lower left ventricular ejection fraction (54.8 ± 15.9 vs 61.1 ± 11.9, p= 0.049) and a more severely impaired index of regional wall motion abnormalities (1.77 ± 0.35 vs 1.18 ± 0.26, p= 0.02) respectively for the CMD-OE and CMD-CE groups.

CONCLUSION

Chronic Chagas cardiomyopathy was a secondary cause of suspected coronary microvascular disease in 15% of 101 stable patients whose cardinal symptom was anginal pain warranting coronary angiography. Although sharing several clinical, hemodynamic, and myocardial perfusion characteristics with patients whose suspected CMD was due to other etiologies, impairment of LV segmental and global systolic function was significantly more severe in the patients with suspected CMD related to Chagas cardiomyopathy. (Arq Bras Cardiol. 2020; 115(6):1094-1101).

Systemic microvascular endothelial dysfunction is associated with left ventricular ejection fraction reduction in chronic Chagas disease patients

OBJECTIVE

This study compares microvascular reactivity (MR) in chronic Chagas disease (CD) patients with healthy individuals, matched for sex and age. In addition, we evaluated the association between MR and left ventricular ejection fraction (LVEF) in patients.

METHODS

Acetylcholine iontophoresis was performed on the forearm skin, using laser speckle contrast imaging, to evaluate endothelium-dependent vasodilation. Clinical data were obtained from medical records.

RESULTS

Thirty-six patients were compared to 25 healthy individuals (controls). Vasodilation was higher in controls, when compared to patients (p < .0001). There was a significant association between LVEF, stratified into quartiles, and MR (p-value for linear trend = .002). In addition, there was no difference in MR between patients with normal LVEF and the control group. In patients, MR was independent of the presence of arterial hypertension or diabetes.

CONCLUSIONS

We have shown for the first time that the reduction of MR is associated with a decrease of LVEF in a cohort of chronic CD patients. The results were not affected by comorbidities, such as hypertension or diabetes. The evaluation of systemic endothelial function may be useful to tailor therapeutic and preventive approaches, targeted at systolic left ventricular failure associated with chronic CD cardiomyopathy.

Infectious myocarditis: the role of the cardiac vasculature

Infectious myocarditis is the result of an immune response to a microbial infection of the heart. The blood vessels of the heart, both the intramyocardial microvasculature and the large epicardial coronary arteries, play an important role in the pathogenesis of infectious myocarditis. First of all, in addition to cardiomyocytes, endothelial cells of the cardiac (micro)vasculature are direct targets for infection. Moreover, through the expression of adhesion molecules and antigen presenting Major Histocompatibility Complex molecules, the blood vessels assist in shaping the cellular immune response in infectious myocarditis. In addition, damage and dysfunction of the cardiac (micro)vasculature are associated with thrombus formation as well as aberrant regulation of vascular tone including coronary vasospasm. These in turn can cause cardiac perfusion abnormalities and even myocardial infarction. In this review, we will discuss the role of the cardiac (micro)vasculature in the pathogenesis of infectious myocarditis.

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.

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.

Precordial chest pain in patients with chronic Chagas disease

Precordial chest pain affects about 15% to 33% of patients with chronic Chagas disease. In the absence of megaesophagus, it should be ascribed to chronic Chagas heart disease. Precordial chest pain is atypical because it can usually neither be associated to physical exercise nor be alleviated by nitroglycerin. However, in certain circumstances, precordial chest pain can masquerade as acute coronary syndrome. Although obstructive coronary artery disease can occasionally be found, microvascular angina seems to be the mechanism behind such phenomenon. Precordial chest pain not always has a benign clinical course; sometimes, it can herald a dismal prognosis. On the basis of cases previously reported, it seems that nitrates, betablockers and/or calcium channel blockers can be of value in the treatment of this condition.