Circulating MicroRNA in patients with repaired tetralogy of Fallot

Abstract

Background: Emerging data suggest that heart-related microRNAs (miRs) may serve as circulating biomarkers of myocardial injury. We aimed to determine the circulating profile of miRs in patients with volume-overloaded right ventricles after repair of tetralogy (TOF).

Materials and methods: A total of 104 TOF patients and 70 controls were recruited. The study was conducted in two phases: (1) determination of circulating heart-related miRs described in left heart diseases (miR-1, miR-133a, miR-208a, miR-208b and miR423-5p) by quantitative real-time PCR in 49 patients and 30 controls and followed by validation in an independent cohort of 55 patients and 40 controls; (2) expression profiling of serum samples from eight patients and eight controls, followed by validation. Alteration in circulating miRNA expression was related to cardiac functional indices as assessed by 2D speckle tracking and 3D echocardiography.

Results: No significant differences in serum levels of left heart-associated miRNAs were found between patients and controls. Of the candidate 19 miRNAs identified by profiling, upregulation of miR-99b and down-regulation of miR-766 were validated. However, no correlations were found between miRs levels and echo indices.

Conclusion: In young adults with repaired TOF and volume-overloaded right ventricles, circulating levels of miR-99b and miR-766, but not left heart-associated miRNAs, were significantly altered.

Keywords: Circulating microRNA; tetralogy of Fallot.