Infectious agents and inflammation in donated hearts and dilated cardiomyopathies related to cardiovascular diseases, Chagas' heart disease, primary and secondary dilated cardiomyopathies.

BACKGROUND: Clinical and experimental conflicting data have questioned the relationship between infectious agents, inflammation and dilated cardiomyopathy (DCM). OBJECTIVES: The aim of this study was to determine the frequency of infectious agents and inflammation in endomyocardial biopsy (EMB) specimens from patients with idiopathic DCM, explanted hearts from different etiologies, including Chagas' disease, compared to donated hearts. METHODS: From 2008 to 2011, myocardial samples from 29 heart donors and 55 patients with DCMs from different etiologies were studied (32 idiopathic, 9 chagasic, 6 ischemic and 8 other specific etiologies). Inflammation was investigated by immunohistochemistry and infectious agents by immunohistochemistry, molecular biology, in situ hybridization and electron microscopy. RESULTS: There were no differences regarding the presence of macrophages, expression of HLA class II and ICAM-I in donors and DCM. Inflammation in Chagas' disease was predominant. By immunohistochemistry, in donors, there was a higher expression of antigens of enterovirus and Borrelia, hepatitis B and C in DCMs. By molecular biology, in all groups, the positivity was elevated to microorganisms, including co-infections, with a higher positivity to adenovirus and HHV6 in donors towards DCMs. This study was the first to demonstrate the presence of virus in the heart tissue of chagasic DCM. CONCLUSIONS: The presence of inflammation and infectious agents is frequent in donated hearts, in the myocardium of patients with idiopathic DCM, myocardial dysfunction related to cardiovascular diseases, and primary and secondary cardiomyopathies, including Chagas' disease. The role of co-infection in Chagas' heart disease physiopathology deserves to be investigated in future studies.

Contribuições e limitações dos biomarcadores no diagnóstico e prognóstico da insuficiência cardíaca com fração de ejeção preservada / Contributions and limitations of biomarkers in the diagnosis of heart failure with preserved ejection fraction

A insuficiência cardíaca é uma síndrome clínica de prevalência crescente. Aproximadamente 30-50% dos pacientes com insuficiência cardíaca congestiva têm disfunção diastólica como causa de seus sintomas. No entanto, o diagnóstico de insuficiência cardíaca de fração de ejeção preservada não é tão simples. Neste contexto, cresce o interesse em encontrarmos biomarcadores que possam auxiliar no diagnóstico e na avaliação prognóstica da insuficiência cardíaca de fração de ejeção preservada. As evidências atuais são provenientes de estudos que avaliaram pacientes com disfunção sistólica e diastólica. No entanto, alguns biomarcadores parecem promissores na avaliação de pacientes com disfunção diastólica. Os peptídeos natriuréticos são os biomarcadores mais amplamente estudados. Níveis de peptídeo natriurético do tipo B e da fração N-terminal do peptídeo natriurético do tipo B são mais elevados entre pacientes com disfunção diastólica quando comparados a indivíduos saudáveis e parecem estar relacionados a maior mortalidade intra-hospitalar e maior risco de evento combinado de morte e re-hospitalização. Assim como entre pacientes com disfunção sistólica, pacientes com insuficiência cardíaca de fração de ejeção preservada com troponina elevada também parecem apresentar maior risco de morte e re-hospitalização. Mais recentemente, tem sido descritos biomarcadores de fibrose como galectina-3 e ST2 solúvel e dados da literatura sugerem que quando elevados podem refletir pior prognóstico. De forma geral, biomarcadores que identificam injúria miocárdica; alterações no turnover celular e marcadores de fibrose parecem promissores por refletirem mecanismos fisiopatológicos da insuficiência cardíaca de fração de ejeção preservada. Assim, estudos prospectivos envolvendo especificamente esta população ainda são necessários para que o real papel destes biomarcadores seja estabelecido.

Heart Failure is a disease whose prevalence has been increasing in the last years. About 30-50% of patients with congestive heart failure have heart failure with preserved ejection fraction (HF-pEF) as the cause of their symptoms. However, the diagnosis of HF-pEF is not so easy to be established. In this context, multiple biomarkers of heart failure have emerged recently and have been used to help in the diagnosis and prognosis of HF-pEF. Current evidence about biomarkers in heart failure comes from trials that involved patients with systolic and diastolic dysfunction. There are few studies involving exclusively patients with HF-pEF. Nevertheless, some biomarkers seem to be promising in patients with HF-pEF. Natriuretic peptides are the most common biomarkers of heart failure, B-type natriuretic peptide and N-terminal B-type natriuretic peptide are higher in patient with diastolic dysfunction when compared to healthy people and seem to be related with higher in-hospital mortality and higher risk of death and re-hospitalization. Patients with HF-pEF, who have high levels of troponin, have also higher risk of death and re-hospitalization. Recently, new biomarkers of fibrosis as 3-galectin and soluble ST2 have been described and data suggest that high levels of these biomarkers should reflect worse prognosis. In summary, biomarkers of myocardial injury; cellular turnover changes and fibrosis seem to be promising biomarkers of the heart failure with preserved ejection fraction since they could reflect their physiopathological mechanisms. So, we believe that prospective thats involving patients with heart failure with preserved ejection fraction are still necessary to establish the importance of these biomarkers.