Lipomatous hypertrophy of the interatrial septum: a distinct adipose tissue type in COPD?

Objective: Lipomatous hypertrophy of the interatrial septum (LHIS) is a distinct section of epicardial adipose tissue. However, its association with COPD is poorly documented.

Methods: Patients undergoing coronary computed tomography angiography (CTA) for clinical indications were recruited retrospectively and screened for LHIS and COPD. LHIS density and the coronary artery disease profile were quantified by CTA: stenosis severity (coronary artery disease radiological reporting system (CADRADS)), coronary artery calcium (CAC) and high-risk plaque (HRP). COPD patients with LHIS were matched for age and sex, the major cardiovascular risk factors (CVRFs), and compared to controls.

Results: The prevalence of LHIS in all 5466 patients was 5.9%. 151 (72.6%) of 208 patients with COPD had LHIS. LHIS density in COPD patients was higher (-10.93 HU versus -21.1 HU; p<0.001), despite body mass index (BMI) (28.8 versus 27.01 kg·m^-2; p=0.002) being lower. LHIS density was lower in obese (BMI >30 kg·m^-2) patients (20.4 versus 13.6 HU; p=0.02). BMI was inversely correlated with LHIS density (BetaR -0.031; 95% CI: -0.054- -0.008; p=0.007). LHIS density was associated with COPD, but not with BMI on multivariate models. CAC and coronary stenosis severity (CADRADS and >50% stenosis) were not different (p=0.106, p=0.156 and p=0.350, respectively). HRPs were observed more frequently in COPD patients with severe Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages ≥2 (32.3% versus 20.1%; p=0.044), but not when adding mild GOLD stages.

Conclusions: The prevalence of LHIS in COPD patients is high (72.6%), and the adipose tissue density is higher, indicating a higher brown fat component. In obese, patients LHIS density is lower and declines along with BMI. Coronary stenosis severity and calcium were not different; however HRPs were more frequent in severe COPD.