O papel do acúmulo de colágeno no interstício miocárdico na sobrevida dos pacientes com cardiomiopatia dilatada idiopática e chagásica

Abstract

Objective: To find out whether there is a correlation between a myocardial structural marker and the overlife rate of patients with dilated cardiomyopathy. Methods:Using endomyocardial biopsy and 2D-echocardiogram, we studied nine patients with no changes in myocardial structure (control) and 45 patients with severe dilated cardiomyopathy of idiopathic etiology (IDCM) and of Chagasic etiology (CDCM). We analyzed the correlation between the quantity of interstitial myocardial collagen (ICVF) and the overlife rates of these patients. We also evaluated the difference in ICVF between these groups and whether fibrosis interfered on the geometry and function of the myocardium. Results:We observed that ICVF was 15 times higher in cardiomyopathy patients than in the control group, but there was no difference in ICVF between CDCM and IDCM (*p < 0.001) patients. There was no correlation between ICVF and the overlife rate in cardiomyopathy patients (IDCM p = 0.249, and CDCM p = 0.587). We observed a significant correlation between ICVF and left ventricular ejection fraction (LVEF) only for IDCM. There was no correlation between ICVF and left ventricular diastolic diameter in either etiology. Conclusion:There was no difference in myocardial fibrosis between patients with CDCM or IDCM, and there was no correlation between fibrosis and the prognosis either for IDCM or CDCM. There was a correlation between myocardial fibrosis and LVEF only for IDCM.Key words: Collagen, myocardium, prognosis, dilated cardiomyopathy. D i l a t e d c a r d i o m y o p a t h y r e p r e s e n t s 8 7 % o f cardiomyopathies. Idiopathic dilated cardiomyopathy (IDCM) has an indeterminate origin, once secondary causes are ruled out. In the United States, its incidence is estimated at 5 to 8/100,000 inhabitants in the population in general, which represents one fourth of dilated cardiomyopathies, with a prevalence adjusted for age of 36/100,000 of the population in general, a 5-year overlife rate of 25% to 65%, depending on the stage of the disease, and annual mortality of 10,000 cases [1][2][3][4] . Chagasic dilated cardiomyopathy (CDCM) is considered an inflammatory disease secondary to infection by a parasite, Trypanosoma cruzi. Data of the World Health Organization show that approximately ninety million people are exposed to the risk of infection by Trypanosoma cruzi, in that the incidence of such infection in 1995 was of 120,000 new casesIrrespective of the etiology, there is accumulation of collagen in the interstitium and in the perivascular space of the myocardium. Myocardial collagen is known to perform important functions which directly affect the heart's morphology, geometry and functional performance. Shirey et al Clinical, functional and biochemical markers of prognosis in dilated cardiomyopathies and heart failure (HF) are well defined. However, a histological marker has not been established yet. It is therefore important to assess the role of interstitial myocardial collagen as a structural prognostic marker in dilated cardiomyopathies. ...

Measurement of multiple cytokines for discrimination and risk stratification in patients with Chagas’ disease and idiopathic dilated cardiomyopathy

“…Proinflammatory cytokines such as interferon gamma, TNF, and IL-6 are already known to be elevated in serum of CD patients [23,25], while the levels of anti-inflammatory cytokines, IL-10 and IL-17, are reduced with increasing severity of HF in CD patients. Also, cytokines that promote fibrosis and extracellular matrix remodeling might be regulated in CD as PLOS NEGLECTED TROPICAL DISEASES cardiomyopathy due to CD is characterized by diffuse, widespread fibrosis within the myocardium [26,27]. Therefore, further studies are required to identify other pro-and anti-inflammatory cytokines and those that induce fibrosis and extracellular matrix remodeling.…”

“…Considering that HF due to CD is associated with poor prognosis and survival [27,36,37], there is a need to identify those chronically infected, asymptomatic patients with potential to develop HF for early treatment, and distinguish them with DCM. Combination of different spectrum of serum biomarkers may pave the way for such purpose.…”

Comparação do desfecho entre a cardiopatia chagásica e a miocardiopatia dilatada idiopática

“…In fact, the association of mononuclear cell infiltrate throughout the myocardium with large areas of confluent fibrosis, 21 similar to what is seen in catecholamine cardiomyopathy 22 and not seen in IDC patients 23 , can lead to a more severe ventricular remodeling process and, ultimately, death. The presence of myocardial inflammatory cells are capable of producing TNF and interleukin 6, which are increased in serum of Chagas but not in IDC patients, and are prognostic markers of unfavorable outcome 24 .…”

New contribution to the tudy of ventricular remodeling and valve rings in dilated cardiomyopathy: anatomical and histological evaluation

“…Regarding the behavior of the collagen fibers in cardiomyopathies, studies show conflicting results, and there may be increased [ 21 ] or decrease [ 20 ] of the collagenous component as well as breakdown of normal structure. Weber et al [ 8 ] , in histological study analyzing three hearts of patients who died due to idDCM, reported that there was a decrease of type I collagen (tougher) and increased collagen type III (less resistant) compared to the normal pattern and loss of normal functional architecture of collagenous fibers.…”