Connecting epicardial adipose tissue and heart failure with preserved ejection fraction: mechanisms, management and modern perspectives

Abstract

Obesity is very common in patients with heart failure with preserved ejection fraction (HFpEF) and it has been suggested that obesity plays an important role in the pathophysiology of this disease. While body mass index defines the presence of obesity, this measure provides limited information on visceral adiposity, which is probably more relevant in the pathophysiology of HFpEF. Epicardial adipose tissue is the visceral fat situated directly adjacent to the heart and recent data demonstrate that accumulation of epicardial adipose tissue is associated with the onset, symptomatology and outcome of HFpEF. However, the mechanisms by which epicardial adipose tissue may be involved in HFpEF remain unclear. It is also questioned whether epicardial adipose tissue may be a specific target for therapy for this disease. In the present review, we describe the physiology of epicardial adipose tissue and the pathophysiological transformation of epicardial adipose tissue in response to chronic inflammatory diseases, and we postulate conceptual mechanisms on how epicardial adipose tissue may be involved in HFpEF pathophysiology. Lastly, we outline potential treatment strategies, knowledge gaps and directions for further research.

Keywords: Epicardial adipose tissue; HFpEF; Inflammation; Pathophysiology.

Figure 1

Schematic cross‐section view of the myocardial and pericardial layers, with epicardial adipose tissue being directly adjacent to the myocardium.

Figure 2

(A) Infiltrative‐lipotoxic hypothesis in which the epicardial adipose tissue increasingly starts infiltrating the underlying myocardial tissue and releasing pro‐inflammatory adipokines. (B) Pericardial restraint hypothesis in which the epicardial adipose tissue accumulates and mechanically obstructs the myocardium from dilating, therefore causing diastolic dysfunction.

Figure 3

Schematic overview of the pathways by which epicardial adipose tissue (EAT) may accumulate and eventually affect the underlying myocardium, leading to left ventricular (LV) hypertrophy, LV diastolic dysfunction and increased cardiac filling pressures and ultimately resulting in clinical heart failure with preserved ejection fraction (HFpEF).

Figure 4

Three different imaging methods for assessment of epicardial adipose tissue. Red arrows indicate the pericardium. (A) Cardiac magnetic resonance imaging. (B) Computed tomography imaging. (C) Transthoracic echocardiography. AO, aorta; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.