Indicators of Cardiomyopathy in Friedreich’s Ataxia Studied in Clinical Trial
Not all clinical trials vital to understanding Friedreich’s ataxia involve new therapies under evaluation before being marketed as treatment. Ronald Crystal, MD, of Weill Medical College of Cornell University in New York is sponsoring an observational case control study for “Characterization of the Cardiac Phenotype of Friedreich’s Ataxia (FRDA).”
Thirty adult FRDA patients, as well as healthy control participants, will be evaluated for cardiac manifestations that result from FRDA. Four different modes of evaluation are included in the study design: cardiac magnetic resonance imaging, exercise-stress test, echocardiogram, and cardiac-related blood serum parameters. Among these serum proteins are troponin, brain natriuretic peptide (BNP), and creatinine phosphokinase.
It is the goal of the present study to identify cardiac manifestations of FRDA to determine effective means of monitoring and proactively helping patients with FRDA who are likely to develop cardiomyopathy. Individual components of this clinical trial have been studied previously by other institutions. Published in the Journal of the American College of Cardiology, an article from UCLA Medical Center’s John S. Child, MD, FACC, described “Cardiac Involvement in FRDA: A Clinical Study of 75 Patients.” In this study, Dr. Child and colleagues found abnormal electrocardiograms that indicated hypertrophy in the hearts of FRDA patients.
From the Department of Pediatrics in Children’s Hospital of Philadelphia, Dr. Lisa S. Friedman also identified abnormal electrocardiograms in the article “Elevation of Serum Cardiac Troponin I in a Cross-sectional Cohort of Asymptomatic Subjects with Friedreich Ataxia,” published in International Journal of Cardiology. Adding to these results, Dr. Friedman found baseline levels of serum cardiac troponin I were elevated beyond the 99th percentile in both pediatric and adult asymptomatic FRDA patients, indicating a strong association between troponin and FRDA. Troponin regulates cardiac muscle contraction, and abnormalities in troponin would likely influence onset of cardiomyopathy. According to the “2014 European Society of Cardiology Guidelines on Diagnosis and Management of Hypertrophic Cardiomyopathy,” from the European Heart Journal, elevated plasma levels of troponin, as well as BNP, increase the likelihood a patient will experience cardiovascular events, heart failure, or death.
Most prominently, FRDA results in progressive damage to the nervous system and is characterized by poor coordination, altered gait, and speech problems. Additionally, it is known that FRDA contributes to other diseases such as diabetes and heart disease, with heart disease manifesting in cardiomyopathy. Cardiac complications lead to 60% of FRDA patient deaths, and although only 0.002% of the Caucasian population is affected by FRDA, it is the most common inherited ataxia disorder.