Pericoronary adipose tissue density is increased in patients with recent spontaneous coronary dissection

Inflammatory activity is one of the potential mechanisms of spontaneous coronary artery dissection (SCAD). Recently, the pericoronary adipose tissue attenuation (PCAT) derived from CT angiography (CTA) has been established as a method for measuring vascular inflammation. We aimed to characterise the pancoronary and vessel-specific PCAT in patients with and without recent SCAD.The study comprised patients with SCAD referred to a tertiary centre between 2017 and 2022 who underwent CTA and were compared with individuals with no prior SCAD. PCAT was analysed on end-diastolic CTA reconstructions along proximal 40 mm of all major coronary vessels as well as the SCAD-related vessel. We analysed 48 patients with recent SCAD (median 6.1 (IQR 3.5-14.9) months since SCAD, 95.8% female) and 48 patients in the group without SCAD.Pancoronary PCAT was higher in patients with SCAD compared with those without SCAD (-80.6±7.9 vs -85.3 HU±6.1, p=0.002). Vessel-specific PCAT in patients with SCAD compared with patients without SCAD was higher for both the RCA (-80.9±9.5 vs -87.1±6.9 HU, p=0.001) and the LCA (-80.3±7.8 vs -83.4±7.2 HU, p=0.04). In patients with SCAD, PCAT of the SCAD-related vessel was not significantly different from averaged PCAT of unaffected vessels (-81.2±9.2 vs -80.6±7.6, p=0.74). There was no association between PCAT and the interval from SCAD to CTA.Patients with recent SCAD have higher PCAT compared with patients without SCAD, suggesting an increased perivascular inflammatory activity. This association is not restricted to the dissected vessel.