MicroRNA biomarkers for failing hearts?

This editorial refers to ‘Multivariate miRNA signatures as biomarkers for non-ischaemic systolic heart failure’†, by B. Vogel et al., on page 2812 Vogel etal.1 report findings from a case–control study looking at microRNA (miRNA) signatures of heart failure (HF). Initial screening was performed on a microarray platform: 883 miRNAs and miRNA* sequences were measured in 53 patients with diagnosis of non-ischaemic systolic HF with reduced left ventricular ejection fraction (LVEF <50%) and 39 controls. Importantly, cases and controls were free of significant coronary artery disease. The best performance was observed for miR-558, miR-122*, and miR-520d-5p. A combination of eight miRNAs further improved test sensitivity and specificity, achieving an area under the curve (AUC) of 0.81. MiRNA measurements were compared with N-terminal pro brain natriuretic peptide (NT-proBNP), an established biomarker for HF. Validation was performed in an independent but even smaller cohort of 14 non-ischaemic HF patients and 8 controls by quantitative real-time polymerase chain reaction (qPCR). Two out of nine biomarker candidates identified in the screening cohort achieved statistical significance in the validation cohort. Consistent with a previous report by Tijsen et al.,2 miR-622 was elevated in HF. MiR-1228 has not been implicated in HF so far. Several small-scale studies have looked at association of miRNAs and HF in serum or plasma.2–5 The present study stands out for providing miRNA data in full blood and for providing correlations of miRNAs with white blood cells.