Fibrose do músculo cardíaco é fator preditivo da função cardíaca na distrofia muscular de Duchenne e aumenta com a idade e o uso de cortícóides
USA – O uso de corticóides é considerado como único tratamento da distrofia muscular de Duchenne. No entanto seu uso tem sido muito avaliado sobre a função muscular e poucas vezes sobre a função cardíaca. Nesta pesquisa os autores avaliaram a função cardíaca em Duchenne através da ressonância nuclear magnética. Os resultados demonstraram que o grau de fibrose aumenta com a idade e com o uso de corticóides e reflete diretamente com a função cardíaca. Nesta mesma publicação há um editorial que reforça a necessidade de tratamento com corticóides visto que é a única opção de tratamento e discute todas as resalvas com relação a estes resultados.
O resumo em inglês e o editorial na íntegra podem ser lidos abaixo:
(Journal of American Heart Association, 2015) Myocardial Fibrosis Burden Predicts Left Ventricular Ejection Fraction and Is Associated With Age and Steroid Treatment Duration in Duchenne Muscular Dystrophy
Animesh Tandon, Chet R. Villa, Kan N. Hor, John L. Jefferies, Zhiqian Gao, Jeffrey A. Towbin, Brenda L. Wong, Wojciech Mazur, Robert J. Fleck, Joshua J. Sticka, D. Woodrow Benson, and Michael D. Taylor – USA
Background Patients with Duchenne muscular dystrophy exhibit progressive cardiac and skeletal muscle dysfunction. Based on prior data, cardiac dysfunction in Duchenne muscular dystrophy patients may be influenced by myocardial fibrosis and steroid therapy. We examined the longitudinal relationship of myocardial fibrosis and ventricular dysfunction using cardiac magnetic resonance in a large Duchenne muscular dystrophy cohort.
Methods and Results We reviewed 465 serial cardiac magnetic resonance studies (98 Duchenne muscular dystrophy patients with ≥4 cardiac magnetic resonance studies) for left ventricular ejection fraction (LVEF) and presence of late gadolinium enhancement (LGE), a marker for myocardial fibrosis. LVEF was modeled by examining LGE status, myocardial fibrosis burden (as assessed by the number of LGE‐positive left ventricular segments), patient age, and steroid treatment duration. An age‐only model demonstrated that LVEF declined 0.58±0.10% per year. In patients with both LGE‐negative and LGE‐positive studies (n=51), LVEF did not decline significantly over time if LGE was absent but declined 2.2±0.31% per year when LGE was present. Univariate modeling showed significant associations between LVEF and steroid treatment duration, presence of LGE, and number of LGE‐positive left ventricular segments; multivariate modeling showed that LVEF declined by 0.93±0.09% for each LGE‐positive left ventricular segment, whereas age and steroid treatment duration were not significant. The number of LGE‐positive left ventricular segments increased with age, and longer steroid treatment duration was associated with lower age‐related increases
Conclusion Progressive myocardial fibrosis, as detected by LGE, was strongly correlated with the LVEF decline in Duchenne muscular dystrophy patients. Longer steroid treatment duration was associated with a lower age‐related increase in myocardial fibrosis burden.
Glucocorticoid Therapy for Duchenne Cardiomyopathy: A Hobson’s Choice?
Subha V. Raman and Linda H. Cripe
