Pericoronary adipose tissue attenuation assessed by ultra-high-resolution CT post COVID-19

COVID-19 infection has been linked to atherosclerosis development and progression through inflammatory pathways; however, the long-term effect on coronary inflammation in a general population, without known coronary artery disease (CAD), is not well established. Pericoronary adipose tissue attenuation (PCAT) is a marker of vascular inflammation and its detailed assessment by an ultra-high-resolution coronary CT (UHR-CT), with enhanced spatial resolution, can provide insights into post-COVID vascular inflammation profile.

To evaluate PCAT attenuation in patients undergoing UHR-CT across different time intervals since COVID-19 infection and its association with cardiovascular (CV) risk profiles, CAD severity, and hospitalization history.

Patients with prior COVID-19 infection and no CAD suspicion were enrolled in a study protocol including coronary UHR-CT (160x0.25mm slices) from 01/2021 to 01/2025.

The proximal 40mm in the right coronary artery was traced to obtain the mean PCAT within a 3 mm radius from the outer vessel wall using dedicated commercial software. This value was normalized to the average attenuation in the ascending aorta to account for acquisition settings variations. Coronary artery stenosis severity was visually assessed, and patients were classified into CAD-RADS categories. Baseline CV risk was determined using PREVENT and ASCVD scores.

Statistical analyses included linear regression to assess the relationship between PCAT and time since COVID-19 infection. PCAT values were compared across CV risk categories, CAD-RADS groups, and hospitalization status using Kruskal-Wallis and Wilcoxon tests, with additional linear regression adjustments for time.

Baseline characteristics and UHR-CT findings of the 136 participants are shown in Table 1. The population was predominantly low-risk and incidental CAD was identified in 59 patients (43.4%). The median time between COVID diagnosis and UHR-CT acquisition was 1.2 (0.5–2.3) years. The scatterplot (Figure 1A) shows the distribution of PCAT values relative to the time interval between COVID-19 diagnosis and imaging with a trend toward more negative PCAT values with increasing time since COVID-19 (p = 0.10). When stratified by CV risk, PCAT attenuation was significantly less negative in individuals classified as low-risk compared to those in higher-risk groups combined (-80.4 vs -82.5, p-value adjusted for time between tests = 0.007) (Figure 1B). No difference in PCAT values was observed across different CAD-RADs categories or according to hospitalization status, even when adjusted for the time between tests.

In patients post COVID infection without known CAD, there is a trend towards more negative PCAT over time suggesting that it might be a predictor of vascular inflammation in patients with no prior CAD detected. A second CT at different time point may help clarify the evolution of post-COVID vascular changes.

Baseline data and UHR-CT Findings