Circulating miR-423_5p fails as a biomarker for systemic ventricular function in adults after atrial repair for transposition of the great arteries

BackgroundRecently, the microRNA miR-423_5p was identified as a biomarker for left ventricular heart failure. Its role in patients with a systemic right ventricle and reduced ejection fraction after atrial repair for transposition of the great arteries has not been evaluated.MethodsIn 41 patients and 10 age- and sex-matched healthy controls circulating miR-423_5p concentration was measured and correlated to clinical parameters, cardiac functional parameters assessed by magnetic resonance imaging, and cardiopulmonary exercise testing.ResultsLevels of circulating miR-423_5p showed no difference between patients and controls. Further, there was no correlation between miR-423_5p and parameters of cardiopulmonary exercise testing or imaging findings.ConclusionsIn patients with a systemic right ventricle and reduced ejection fraction miR-423_5p levels are not elevated. Therefore, circulating miR-423_5p is not a useful biomarker for heart failure in this patient group.