Characterizing Friedreich's ataxia cardiomyopathy with serial cardiac magnetic resonance imagings

Friedreich's ataxia (FA) is a hereditary neuromuscular disorder with cardiac involvement as the leading cause of death. This study examines the progression of cardiac magnetic resonance imaging (CMR) biomarkers in FA-associated cardiomyopathy and their relationships with clinical outcomes.

This retrospective, single-center study included FA patients with at least one CMR. CMR assessment included segmental late gadolinium enhancement (LGE), left ventricle (LV) ejection fraction (EF), LV wall thickness, native T1 mapping, and extracellular volume (ECV) fraction. Linear mixed-effects regression models were used to assess CMR parameters in relation to each other and time.

Fifteen patients (mean age: 22.7 ± 7.6 years) and 37 CMRs were evaluated over an average of 11.0 ± 5.0 years from neuromuscular symptom onset. LV thickness was most notable along the septum, while LGE was localized to the LV free wall. Native T1 and ECV were globally elevated. Six (40%) patients demonstrated LGE, and those negative at baseline remained negative. LGE increased by 0.5 segments per year ( P = 0.25), and LVEF declined by 0.73%/year ( P = 0.06); however, neither reached statistical significance. LV thickness, native T1, and ECV did not change significantly. Maximal LV thickness correlated with cardiac symptoms ( P = 0.04) and cardiac medications ( P = 0.024).

In this exploratory study, CMR demonstrated patterns of septal hypertrophy, lateral wall fibrosis, and trends toward declining ventricular function. Findings were largely nonsignificant and should be considered hypothesis-generating. Larger, multicenter studies are needed to clarify the role of CMR in disease progression and clinical management.