Coronary Perivascular Adipose Tissue Characteristics Are Related to Atherosclerotic Plaque Size and Composition. A Post-mortem Study

Background: Perivascular adipose tissue (pvAT) may influence atherosclerotic plaque formation. We aim to determine the association between the local amount and inflammatory properties of pvAT and the size and composition of atherosclerotic plaque in the left anterior descending artery (LAD).

Methods: Post-mortem, a total of 139 cross sections of the LAD were obtained from 16 patients. PvAT quantity was measured within an area of 3 mm around the LAD (pvAT-area (%)). Furthermore, inflammatory properties of pvAT were measured (macrophages/400× field and adipocyte size). From plaque area (mm(2)), plaque/media-ratio was calculated and morphologic characteristics were scored (presence of a lipid core and calcification; collagen and smooth muscle cell content; macrophage (<10, 10-50, >50/400× field) and lymphocyte infiltration (<10, 10-25, >25/400× field)).

Results: Plaque/media-ratio increased with increasing pvAT-area (β0.02; 95%CI 0.01-0.03) and pvAT-macrophages (β 0.10; 95%CI 0.05-0.16), but not with adipocyte area (β -0.00; 95%CI -0.07-0.06). PvAT-area was related to the presence of a lipid core (OR 1.05; 95%CI 1.03-1.08) and with macrophage and lymphocyte infiltration of atherosclerotic plaque (per increase in category OR 1.05; 95%CI 1.02-1.07 and OR 1.04; 95%CI 1.01-1.07 respectively). PvAT macrophage infiltration was correlated with adventitia and plaque macrophages.

Conclusion: PvAT quantity and macrophage infiltration are highly related to atherosclerotic plaque size and composition in patients with coronary atherosclerosis. These results indicate potential involvement of pvAT in coronary atherosclerotic plaque development, although the causality of the relation has yet to be determined.