Differential Expression of microRNAs in Acute and Chronic Heart Failure

Background: MicroRNAs modify protein expression at the post-transcriptional level, and their circulating levels may help identify the underlying molecular pathways. Objective: The purpose of this study was to assess the differential expression of microRNAs related to myocardial cell energy substrate, autophagy, and ischaemia in chronic and acute heart failure (HF). Methods: In this case-control study, we studied 19 patients with acute HF (AHF) and 19 patients with chronic HF (CHF). Basic demographic and clinical characteristics were collected from the patients upon arrival, at 48 hours, and at 120 hours. Blood samples for microRNAs measurements (miR-22, -92a, and -499), B-type natriuretic peptide (BNP), C reactive protein, and high sensitivity cardiac troponin I, were collected at all study points. In this study, we included subjects with a left ventricular ejection fraction of Results: At baseline, circulating miR-22 levels were 1.9-fold higher (p<0.001), miR-92a levels were 1.25-fold higher (p=0.003), and miR-499 were 5-times lower (p<0.001) in AHF compared to CHF. Interestingly, circulating miR-499 was found to be associated with BNP levels (r=0.47, p=0.01). At follow-up, there was a stepwise increase in the levels of all three examined microRNAs (miR-22, p=0.001, miR-92a, p=0.001, and miR-499, p<0.001) for AHF but not for CHF subjects. Conclusion: MicroRNAs -22, -92a, and -499 are differentially expressed in chronic and acute HF subjects. MicroRNA signatures are also differentially expressed up to the discharge of the patients. These findings may have important implications for diagnosis, progression, and treatment of patients with chronic and acute heart failure.