Circulating microribonucleic acids miR-1, miR-21 and miR-208a in patients with symptomatic heart failure: Preliminary results.

Background: Cardiomyocytes produce a wide variety of bioactive molecules that regulate numerous physiological and pathophysiological processes. Recently, it has been recognized that changes in microribonucleic acid (miRNA) expression may lead to cardiac dysfunction.

Aims: To assess the expression of circulating miRNAs (miR-1, miR-21 and miR-208a) in patients with symptomatic heart failure (HF), and to investigate the relationship between expression of these miRNAs and secretion of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and galectin-3.

Methods: Thirty-five patients in New York Heart Association (NYHA) class II/III (age: 68.8 ± 13.0 years) and 26 patients in NYHA class IV (age: 72.0 ± 10.4 years) hospitalized in the intensive coronary care unit participated in the study. Serum concentrations of miRNAs were measured by quantitative real-time polymerase chain reaction. Basic biochemical assays were carried out, and NT-proBNP and galectin-3 concentrations were measured in all serum samples.

Results: miR-1 was downregulated in patients with symptomatic HF and its expression decreased with severity of NYHA class (P=0.007). In contrast, overexpression of miR-21 was seen in all patients, independent of HF severity. Results suggest no miR-208a leakage into the circulation in patients with symptomatic HF. There was an inverse relationship between miR-1 expression and NT-proBNP concentration (Spearman's rank correlation coefficient [r]=-0.389; P=0.023) in patients in NYHA class II/III. Overexpression of miR-21 correlated significantly with galectin-3 concentration (r=0.422; P=0.032).

Conclusion: Dysregulation of miR-1 and miR-21 expression may be essential for the development of HF; miR-1 might become a biomarker for predicting HF exacerbation.