Periaortic adipose tissue index: A new approach to the relationship between coronary stenosis severity/lesion complexity and periaortic adipose tissue

Periaortic adipose tissue (PAT) is associated with atherosclerosis. The severity of coronary stenosis with PAT has not been evaluated with conventional coronary angiography (CAG). The aim of the study is to determine the relationship between PAT and coronary stenosis severity/ complexity, and to evaluate it with the periaortic adipose tissue index (PATI), a new index derived from PAT. Patients who underwent CAG and thoracic computed tomography (CT) between January 2017 and January 2022 were included in the study. PAT volume was calculated by evaluating CT images, and PATI was calculated by dividing the PAT volume by the circumference of the descending aorta. Patients were divided into two groups according to the presence of ≥50% stenosis on CAG. The correlation of PAT and PATI with the SYNTAX score was evaluated. In our study, 263 patients [mean age 64.5(54/72), male 164 (62.4%)] were evaluated. Severe coronary artery disease (CAD) was observed in 181 patients (68.8%). PAT volume and PATI were significantly higher in patients with severe stenosis (p<0.001, for both). When PAT and PATI were evaluated alongside CAD risk factors, an independent association between PATI and severe CAD was discovered (β:0.581, p:0.97, β:0.968, p:0.006, respectively). No correlation was found between SYNTAX score and PAT and PATI (r:-0.026, p:0.73, r:-0.019, p:0.19, respectively). In our study, PAT and PATI were higher in patients with severe coronary stenosis, and there was an independent relationship between PATI and severe stenosis. We found no relationship between PAT and PATI and the SYNTAX score.