Background. Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America and affects 10 million people worldwide. Approximately 12 000 deaths attributable to Chagas disease ...occur annually due to chronic Chagas disease cardiomyopathy (CCC), an inflammatory cardiomyopathy presenting with heart failure and arrythmia; 30% of infected subjects develop CCC years after infection. Genetic mechanisms play a role in differential progression to CCC, but little is known about the role of epigenetic modifications in pathological gene expression patterns in CCC patients' myocardium. DNA methylation is the most common modification in the mammalian genome. Methods. We investigated the impact of genome-wide cardiac DNA methylation on global gene expression in myocardial samples from end-stage CCC patients, compared to control samples from organ donors. Results. In total, 4720 genes were differentially methylated between CCC patients and controls, of which 399 were also differentially expressed. Several of them were related to heart function or to the immune response and had methylation sites in their promoter region. Reporter gene and in silico transcription factor binding analyses indicated promoter methylation modified expression of key genes. Among those, we found potassium channel genes KCNA4 and KCNIP4, involved in electrical conduction and arrythmia, SMOC2, involved in matrix remodeling, as well as enkephalin and RUNX3, potentially involved in the increased T-helper 1 cytokine-mediated inflammatory damage in heart. Conclusions. Results support that DNA methylation plays a role in the regulation of expression of pathogenically relevant genes in CCC myocardium, and identify novel potential disease pathways and therapeutic targets in CCC.
Ischemic cardiomyopathy and severe left ventricular dysfunction are well established to represent the main determinants of poor survival and premature death compared with preserved ventricular ...function. However, the role of myocardial revascularization as a therapeutic alternative is not known to improve the long-term prognosis in this group of patients. This study will investigate whether myocardial revascularization contributes to a better prognosis for patients compared with those treated with drugs alone and followed over the long term.
The study will include 600 patients with coronary artery disease associated with ischemic cardiomyopathy. The surgical or drug therapy option will be randomized, and the events considered for analysis will be all-cause mortality, nonfatal infarction, unstable angina requiring additional revascularization, and stroke. The events will be analyzed according to the intent-to-treat principle. Patients with multivessel coronary disease and left ventricular ejection fraction measurements of less than 35% will be included. In addition, myocardial ischemia will be documented by myocardial scintigraphy. Markers of myocardial necrosis will be checked at admission and after the procedure.
The role of myocardial revascularization (CABG) in the treatment of patients with coronary artery disease and heart failure is not clearly established. The surgical option of revascularizing the myocardium is a procedure designed to reduce the load of myocardial hibernation in patients with heart failure caused by coronary artery disease. On the other hand, the assessment of myocardial viability is frequently used to identify patients with left ventricular ischemic dysfunction in which CABG may add survival benefit. However, the effectiveness of this option is uncertain. The great difficulty in establishing the efficacy of surgical intervention is based on the understanding of viability without ischemia. Thus, this study will include only patients with viable and truly ischemic myocardium to correct this anomaly.
Evaluation of a randomized comparison between patients with coronary artery disease associated with ischemic cardiomyopathy submitted to medical or surgical treatment: MASS-VI (HF), ISRCTN77449548, Oct 10th, 2019 (retrospectively registered).
Resumo Fundamento A Doença de Chagas (DC) é uma causa importante de transplante cardíaco (TC). O principal obstáculo é a reativação da DC (RDC), normalmente associada a altas doses de ...imunossupressores. Estudos anteriores sugeriram uma associação do micofenolato de mofetila com aumento na RDC. No entanto, preditores de mortalidade são desconhecidos. Objetivos Identificar os fatores de risco de mortalidade em pacientes com DC após o TC e o impacto do regime antiproliferativo sobre a sobrevida. Métodos Estudo retrospectivo com pacientes chagásicos submetidos ao TC entre janeiro de 2004 e setembro de 2020, em protocolo de imunossupressão que priorizava o uso de azatioprina e sua mudança para micofenolato de mofetila em caso de rejeição. Realizamos regressão univariada para identificar preditores de mortalidade e comparamos sobrevida, rejeição, e evidência RDC entre os pacientes que usavam azatioprina, micofenolato de mofetila, e aqueles que mudaram de azatioprina para micofenolato (grupo “Mudança”) após a alta. Um valor de p<0,05 foi considerado estatisticamente significativo. Resultados Foram incluídos 85 pacientes, 54,1% homens, idade mediana 49 (39-57) anos, e 91,8% com prioridade na lista de espera. Dezenove (22,4%) usavam azatioprina, 37 (43,5%) micofenolato de mofetila, e 29 (34,1%) trocaram a terapia; a sobrevida não foi diferente entre os grupos, 2,9 (1,6-5,0) x 2,9 (1,8-4,8) x 4,2 (2,0-5,0) anos, respectivamente; p=0,4. Não houve diferença na taxa de rejeição (42%, 73% e 59% respectivamente; p=0,08) ou de RDC (T. cruzi positiva na biópsia endomiocárdica 5% x 11% x 7%; p=0,7; uso benzonidazol 58% x 65% x 69%; p=0,8; PCR positiva para T. cruzi 20% x 68% x 42% respectivamente; p=0,1). Conclusões Este estudo retrospectivo com pacientes com DC e TC não mostrou diferença na sobrevida entre os diferentes regimes antiproliferativos. O uso de micofenolato de mofetila não foi associado com taxas significativamente mais altas de RDC ou rejeição do enxerto nesta coorte. Novos ensaios randomizados são necessários para abordar essa questão.
Chronic Chagas disease (CCC) is an inflammatory dilated cardiomyopathy with a worse prognosis compared to other cardiomyopathies. We show the expression and activity of Matrix Metalloproteinases ...(MMP) and of their inhibitors TIMP (tissue inhibitor of metalloproteinases) in myocardial samples of end stage CCC, idiopathic dilated cardiomyopathy (DCM) patients, and from organ donors. Our results showed significantly increased mRNA expression of several MMPs, several TIMPs and EMMPRIN in CCC and DCM samples. MMP-2 and TIMP-2 protein levels were significantly elevated in both sample groups, while MMP-9 protein level was exclusively increased in CCC. MMPs 2 and 9 activities were also exclusively increased in CCC. Results suggest that the balance between proteins that inhibit the MMP-2 and 9 is shifted toward their activation. Inflammation-induced increases in MMP-2 and 9 activity and expression associated with imbalanced TIMP regulation could be related to a more extensive heart remodeling and poorer prognosis in CCC patients.
ABSTRACT Introduction: The aims of this study were to determine the incidence of severe and moderate primary graft dysfunction (PGD) in our center, to identify, retrospectively, donors’ and ...recipients’ risk factors for PGD development, and to evaluate the impact of PGD within 30 days after heart transplantation. Methods: Donors’ and recipients’ medical records of 64 consecutive adult cardiac transplantations performed between January 2016 and June 2017 were reviewed. The International Society for Heart and Lung Transplantation (ISHLT) criteria were used to diagnose moderate and severe PGD. Associations of risk factors for combined moderate/severe PGD were assessed with appropriate statistical analyses. Results: Sixty-four patients underwent heart transplantation in this period. Twelve recipients (18.7%) developed severe or moderate PGD. Development of PGD was associated with previous donor cardiopulmonary resuscitation and a history of prior heart surgery in the recipient (P=0.01 and P=0.02, respectively). The 30-day in hospital mortality was similar in both PGD and non-PGD patients. Conclusion: The use of the ISHLT criteria for PGD is important to identify potential risk factor. The development of PGD did not affect short-term survival in our study. More studies should be done to better understand the pathophysiology of PGD.
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