Circulating microRNA‐29‐5p can add to the discrimination between dilated cardiomyopathy and ischaemic heart disease

AIMS: Heart failure describes a large and heterogeneous spectrum of underlying cardiac diseases. MicroRNAs (miRs) are small non‐coding RNAs that in recent years have been shown to play an important role in the pathogenesis of heart failure. Cardiac magnetic resonance imaging is a powerful imaging modality for the evaluation of cardiac characteristics in heart failure. In this study, we sought to compare heart failure patients with a diagnosis of either idiopathic dilated cardiomyopathy (DCM) or ischaemic heart disease (IHD), in the context of serum levels of certain miRs and also magnetic resonance imaging parameters of cardiac structure and function. METHODS AND RESULTS: A total of 135 subjects were studied: 53 patients with DCM (age: 59 ± 12 years, mean ± SD), 34 patients with IHD (66 ± 9 years), and 48 controls (64 ± 5 years). The participants underwent baseline medical examination, blood sampling, and a cardiac magnetic resonance imaging examination at 3 Tesla (Philips Ingenia). The serum levels of seven different miRs were analysed and assessed: 16‐5p, 21‐5p, 29‐5p, 133a‐3p, 191‐5p, 320a, and 423‐5p, all of which have been demonstrated to play potential roles in the pathogenesis of heart failure. The patients in the DCM and IHD groups had left ventricles that had larger end‐diastolic volume (P < 0.001), larger mass (P < 0.001), and lower ejection fraction (P < 0.001) compared with controls. Serum levels of miR‐29‐5p were increased in DCM compared with IHD (P < 0.005) and serum levels of miR‐320a were elevated in DCM compared with healthy controls (P < 0.05). There was no significant association between miR levels and magnetic resonance imaging parameters of left ventricular structure and function. CONCLUSIONS: Circulating miR‐320a can add to the discrimination between patients with DCM and healthy controls and circulating miR‐29‐5p can add to the discrimination between DCM and IHD.