Lipomatous Hypertrophy of the Interatrial Septum (LHIS) a Biomarker for Cardiovascular Protection? A Hypothesis Generating Case–Control Study

<b>Background:</b> While epicardial adipose tissue (EAT) is a known predictor of adverse cardiovascular outcomes, lipomatous hypertrophy of the interatrial septum (LHIS) is composed of metabolically active fat such as brown adipose tissue, which may exert a different effect. This study investigates the coronary atherosclerosis profile in patients with LHIS using CTA, compared with a propensity score-matched control group. <b>Methods:</b> A total of 142 patients were included (<i>n</i> = 71 with LHIS and <i>n</i> = 71 controls) and propensity score-matched for age, gender, BMI, and the major CV risk factors (matching level, <0.05). CTA imaging parameters included HRP, coronary stenosis severity (CADRADS), and CAC score. <b>Results</b>: The mean age was 60.9 years +/- 10.6, there were nine (6.3%) women, and the mean BMI is 28.04 kg/m² +/- 4.99. HRP prevalence was significantly lower in LHIS patients vs. controls (21.1% vs. 40.8%; <i>p</i> < 0.011), while CAC (<i>p</i> = 0.827) and CADRADS (<i>p</i> = 0.329) were not different, and there was no difference in the obstructive disease rate. There was no difference in lipid panels (cholesterol, LDL, HDL, TG) and statin intake rate. <b>Conclusions:</b> HRP prevalence is lower in patients with LHIS than controls, while coronary stenosis severity and CAC score are not different. <b>Clinical relevance:</b> LHIS may serve as imaging biomarker for reversed CV risk.