Evolutional change in epicardial fat and its correlation with myocardial diffuse fibrosis in heart failure patients.

OBJECTIVES: The aim of this study was to characterize the characteristics of epicardial fat (EAT) in different stage heart failure (HF) patients and its relationship between cardiac fibrosis.

BACKGROUND: EAT is visceral adipose tissue that possesses inflammatory properties. Inflammation and obesity are associated with cardiac fibrosis, but the relationship between cardiac fibrosis and EAT is unknown.

METHODS: EAT volume was measured using cardiac magnetic resonance imaging (CMR) in 180 subjects: 58 patients with systolic HF, 63 patients with HF and preserved ejection fraction, and 59 patients without HF. CMR derived myocardial extracellular volume (ECV) was used for fibrosis quantification.

RESULTS: Patients with systolic HF had significantly more EAT compared with patients with HF and preserved ejection fraction or the control group (patients without HF) (indexed EAT volume [mL/m2 ], 27.0 [22.7-31.6] vs 25.6 [21.4-31.2] and 24.2 [21.0-27.6], P < .05). The adjusted EAT amount was associated with ECV completely independent of age, hypertension, diabetes, etiology of HF, left ventricular ejection fraction, CMR-late gadolinium enhancement (LGE), left ventricular mass index, and left ventricular end-diastolic volume index (correlation coefficient: 0.49; 95% confidence interval: 0.12-0.86, P < .01). Increased CMR ECV was more associated with EAT in those with advanced age, male sex, LGE on magnetic resonance imaging-LGE images, and less left ventricular end-diastolic volume index.

CONCLUSIONS: EAT volume is highly associated with CMR ECV independent of traditional risk factors and left ventricular mass or volume. Whether EAT plays a role in the long-term prognosis of HF requires future investigation.