Thickness and an Altered miRNA Expression in the Epicardial Adipose Tissue Is Associated With Coronary Heart Disease in Sudden Death Victims.

INTRODUCTION AND OBJECTIVES

An increased epicardial adipose tissue (EAT) thickness has become a new risk factor for coronary heart disease (CHD). We aimed to study the role of EAT dysfunction as a CHD marker by focusing on its thickness and microRNA (miRNA) expression profile, and the potential factors possibly influencing them.

METHODS

One hundred and fifty-five CHD sudden cardiac death victims and 84 non-CHD-sudden death controls were prospectively enrolled at autopsy. A representative subset underwent EAT thickness measurements and EAT miRNA expression profiling.

RESULTS

Epicardial adipose tissue thickness was increased and allowed an accurate diagnosis of patient status (among other measurements, EAT score area under the curve 0.718, P < .001). Epicardial adipose tissue from patients showed 14 up- and 14 down-regulated miRNAs and miR-34a-3p, -34a-5p, -124-3p, -125a-5p, 628-5p, -1303 and -4286 were validated by quantitative real-time polymerase chain reaction. Patients exhibited higher EAT levels of miR-34a-3p and -34a-5p than controls (with a positive trend considering EAT from coronaries without stenosis, with stable stenosis and complicated plaques) and correlated with age only in controls. The mild positive correlation between liver and EAT miR-34a-5p levels in patients (r = 0.295, P = .020) dramatically increased in EAT from complicated plaques (r = 0.799, P = .017). Similar correlations were observed for high-sensitivity-C-reactive protein levels and miR-34a-5p levels both in EAT and liver extracts.

CONCLUSIONS

Increased age-independent levels of miR-34a-3p and -34a-5p characterize the EAT miRNA expression profile of CHD regardless of EAT thickness, anthropometric parameters, and the presence of underlying atherosclerotic plaques.