NEW ORLEANS — Treatment of newly diagnosed dilated cardiomyopathy in children with muscular dystrophy can improve the heart's size and function in many cases, John L. Jefferies, M.D., said in a poster at the annual scientific sessions of the American Heart Association.
“The goal is to preserve normal cardiac function. If we catch a patient at the start of ventricular dysfunction, we can start treatment before the ejection fraction is substantially depressed” and symptoms from ventricular dysfunction appear, said Dr. Jefferies, of Texas Children's Hospital, Houston.
Dilated cardiomyopathy, common in muscular dystrophy, responds to therapy. Thus, annual screening by echocardiography should start when a child with muscular dystrophy is about 5 years old, Dr. Jefferies told CLINICAL NEUROLOGY NEWS.
The study involved 69 boys with muscular dystrophy who were referred to the Cardiovascular Genetics Clinic of the Texas Heart Center. Seven had Becker's muscular dystrophy (BMD) and were first seen at an average age of 12.9 years; 62 boys had Duchenne's muscular dystrophy (DMD) and were first examined at an average age of 13.7 years. These boys underwent annual echocardiography, and dilated cardiomyopathy was eventually diagnosed in 4 of the patients with BMD (57%) at an average age of 14 years, and in 27 of those with DMD (44%) at an average age of 16 years. All 31 patients were started on drug therapy. At the time of initial diagnosis, the 31 patients with dilated cardiomyopathy had an average left ventricular ejection fraction (LVEF) of 36% and an average myocardial performance index of 0.53.
Either liquid enalapril or captopril was given to younger children, with a tablet formulation of lisinopril an option for adolescents. If a patient's LVEF failed to improve after 3 months with this treatment, the physicians added a β-blocker, either metoprolol or carvedilol, which both come in liquid formulations
Clinical follow-up was possible for 29 of the 31 treated patients. During an average follow-up of 3.3 years, 19 patients (3 with BMD and 16 with DMD) had complete normalization of their cardiac size and function. Another eight patients, all with DMD, had improvements in cardiac size and function, and three patients, all with DMD, had stabilization of their cardiac size and function, Dr. Jefferies reported. After an average of 3.3 years of treatment, the average LVEF in these 29 patients had improved to 53%, and the average myocardial performance index had improved to 0.38. (Less than 0.41 is considered normal.)