Prevalence of coronary artery ectasia in older adults and the relationship with epicardial fat volume by cardiac computed tomography angiography

Abstract

Objective: Coronary artery ectasia (CAE) refers to abnormal dilation of coronary artery segments to 1.5 times of adjacent normal ones. Epicardial fat is associated with cardiovascular risk factors. The relationship between CAE and epicardial fat has not yet been investigated. This study aimed to assess the relationship between CAE and epicardial fat volume (EFV) in older people by dual-source computed tomography coronary angiography (CTCA).

Methods: We prospectively enrolled 1400 older adults who were scheduled for dual-source CTCA. Under reconstruction protocols, patients with abnormal segments 1.5 times larger than the adjacent segments were accepted as CAE. EFV was measured by semi-automated software. Traditional risk factors in CAE patients, as well as the extent of EFV, were analyzed and compared to non-CAE group.

Results: A total of 885 male and 515 female older patients were enrolled. CAE was identified by univariable analysis in 131 patients and significantly correlated to hypertension, smoking, hyperlipidemia, prior percutaneous coronary intervention and ascending aorta aneurysm. EFV was shown to be significantly higher in CAE patients than patients without ectasia. In multivariable analyses, EFV (P = 0.018), hypertension (P < 0.001) and hyperlipidemia (P < 0.001) were significantly correlated to CAE. There was a significant negative correlation between EFV and Markis classification.

Conclusions: CAE can be reliably recognized by dual-source CTCA. Epicardial fat might play a role in etiopathogenesis and progression of CAE, providing a new target for treating ectasia.

Keywords: Cardiac computed tomography angiography; Coronary artery ectasia; Epicardial fat.

Figure 1.. Characteristics of CAE in CTCA imaging.

Diffuse ectasia of right coronary artery was detected by both MIP and CPR images (A & B); MIP images (C) and CPR images (D) showed localized ectasia in a right coronary artery. The arrow in each image indicated the presence of ectatic lesion. CAE: coronary artery ectasia; CPR: curved multiplanar reconstruction; CTCA: computed tomography coronary angiography; MIP: maximum intensive projection.

Figure 2.. Measurement of the epicardial fat volume.

Both coronary and sagittal images are shown for determination of epicardial fat range (A & B). Using a lower threshold of -195 HU and upper threshold of -45 HU, epicardial fat is segmented and highlighted in red. The epcairdal fat volume is summarized over all cross-sections (C) and in this coronary artery ectasia patient measured 236.87 mL (D).