Expression of miRNA-21 level in hypertrophic cardiomyopathy patients with chronic heart failure and preserved left ventricular ejection fraction: results of a 6-year follow-up

Abstract

Abstract Introduction Recently it is found that circulating miRNA-21 is associated with chronic heart failure (CHF) and ischemic heart disease. Its clinical significance in hypertrophic cardiomyopathy (HCM) and CHF with preserved left ventricular ejection fraction (LVEF) (≥50%) has to be investigated. Purpose The aim of this study was to analyze the expression of miRNA-21 in the peripheral blood of HCM patients and CHF with preserved LVEF (≥50%). Materials and methods From 2014 to 2019 years we examined 180 HCM patients. The study population consisted of 60 patients ≥19 years old (51.5 [36.2; 65.7]) with symptomatic HCM and CHF with preserved LVEF (≥50%). The diagnosis of HCM was established according to the guideline of the European society of cardiology on the diagnosis and treatment of HCM, 2014. The control group included 45 healthy donors without cardiovascular diseases and other severe pathologies, matched by age and sex with the studied group. Total RNA was extracted from plasma of patients. MiRNA-21 and reference RNA U6 cDNA was prepared based on StemLoop-technology. Expression was examined using semiquantitative RT-PCR protocol. Calculation of the relative gene expression level of miRNA-21 was done according to the standard procedure 2-ΔCt. IBM SPSS software package and Microsoft Excel 2010 were used for the statistical analysis of the collected data. Results The serum expression level of miRNA-21 in HCM patients (n=60) varied from 0.13 to 477.7 (4.92 [1.77; 13]) and was significantly higher than those in the control group (0.01 - 9.85 (0.84 [0.55; 1.23]), with statistically significant difference (p=0.001). The HCM group was divided according to CHF severity: I-II functional class (NYHA) (n=42) and III-IV functional class (NYHA) (n=18) subgroups. It was found a significant increase of expression microRNA-21 level in both subgroups HCM patients, compared with control group (p=0.001). The expression level of miRNA-21 also differed between HCM patients and CHF III-IV functional class (NYHA) vs those, who had CHF I-II functional class (NYHA) – 1.1–477.7 (13 [3.88; 41]) vs 0.1–119.4 (3.25 [1.41; 6.06]), respectively (p=0.003). In HCM patients and CHF III-IV functional class (NYHA) (n=18) the expression level of miRNA-21 positively correlated with LVEF (r=0.609; p<0.05). Conclusion HCM patients with CHF III-IV functional class (NYHA) and preserved LVEF (≥50%) demonstrated high expression level of miRNA-21. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Almazov Federal Medical Research Centre, Saint-Petersburg, Russian Federation, Pavlov University, L'va Tolstogo str. 6-8, Saint Petersburg, Russian Federation