Prognostic value of longitudinal strain and ejection fraction in Friedreich's ataxia

Background: Friedreich's ataxia (FA) is a rare autosomal recessive mitochondria! disease most commonly due to a triplet repeat expansion guanine-adenine-adenine (GM) in the FXN gene. Cardiac disease is the major cause of death, patients with reduced left ventricular ejection fraction (LVEF) having the worse prognosis. Longitudinal strain (IS) appeared to be a better predictor of outcome than LVEF in different diseases. We compared the prognostic value of LS measured from the 4 chambers view to LVEF. Methods: From 2003 to 2017 consecutive patients with FA were included and LS analysis was retrospectively performed. Results: We studied 140 patients, with a median age of 34 (26-41) years (Q1-Q3) with age at onset of 14 (11-19) years and GM repeats on the shorter allele of 600 (467-783) pb. Mean IS was 19.9 +/- 5.0% and LVEF 64 +/- 8%. After a mean follow-up of 7.4 +/- 3.9 years, 14 patients died. In univariate Cox analysis, all-cause mortality was associated with: IS (HR 0.83: 95%CI, 0.75-0.91, p = 0.0002). LVEF (HR 0.30; 95%CI, 0.19-0.49,p < 0.0001), GAA repeats on the shorter allele (HR 129; 95%CI, 1.10-1.51, p = 0.002), age at onset (HR 0.87; 95%CI, 0.77-0.98, p = 0.018). LVSystolic Diameter (HR 1.17; 95%CI, 1.09-1.26, p < 0.0001), LVMass index (HR 1.02; 95%CI. 1.00-1.04, p - 0.027), and LVDiastolic Diameter (HR1.12; 95%CI, 1.01-1.23, p = 0.028). In multivariate analysis. LVEF was the only independent predictor of mortality (HR 0.41; 95%CI, 023-0.74, p- 0.0029). Conclusion: In FA.1.5 was not an independent predictor of mortality, LVEF remained the only independent predictor in the present study. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Friedreich's ataxia (FA) is a rare mitochondria! disease with cardiac disease as the major cause of death. This study found that, in FA patients, LVEF was a better independent predictor of mortality compared to LS.