Association of pericoronary inflammation with atherosclerotic plaque progression in diabetic patients with improved modifiable cardiovascular risk factors: a longitudinal CCTA cohort study.

Background: Pericoronary adipose tissue (PCAT) attenuation, as assessed by coronary computed tomography angiography (CCTA), has been identified as a marker of pericoronary inflammation and a predictor of future adverse atherosclerotic events. However, the impact of changes in PCAT attenuation, as evaluated by consecutive CCTAs, on plaque progression in high-risk atherosclerotic patients with improved modifiable cardiovascular risk factors (mCRFs) remains unclear.

Methods: Consecutive patients with type 2 diabetes mellitus (T2DM) who had improved mCRFs and underwent serial, clinically indicated CCTA examinations (time interval ≥ 12 months) at our center between July 2019 and July 2022 were screened. Eligible participants had at least one study plaque, defined as a plaque without significant anatomic stenosis, located in one of the major coronary arteries, which had not been intervened upon or caused adverse events between serial CCTA scans. Percent atheroma volume (PAV) and PCAT attenuation were measured for each study plaque at baseline and follow-up using CCTA plaque analysis software. Changes in PAV (δPAV = follow-up PAV - baseline PAV) were compared based on changes in PCAT attenuation [δPCAT attenuation] (> 0 or ≤ 0). Multivariate linear regression models were used to evaluate the relationship between δPCAT attenuation and δPAV.

Results: A total of 98 T2DM patients (mean age: 59.9 years; 75.3% men; 152 plaques) had mCRFs that reached therapeutic targets at follow-up CCTA. However, overall PAV progressed from baseline in all patients [(41.68 ± 12.47)% vs. (43.71 ± 12.24)%, p = 0.035], accompanied by an increase in coronary inflammation (i.e., PCAT attenuation) during a median follow-up of 13.5 months (interquartile range [IQR]: 12.2, 17.5 months).Compared to patients with δPCAT attenuation ≤ 0, those with δPCAT attenuation > 0 had a significantly greater increase in overall PAV from baseline [(4.09 ± 12.09)% vs. (-0.82 ± 10.74)%, p = 0.011], calcified PAV [1.57% (IQR: 0.13%, 3.84%) vs. 0.38% (IQR: -0.26%, 2.58%), p = 0.008], and a numerical but non-significant increase in non-calcified PAV [(1.29 ± 11.75)% vs. (-1.87 ± 10.47)%, p = 0.089]. Multivariate linear regression models demonstrated that increased PCAT attenuation was significantly associated with the progression of overall PAV (β = 0.339, 95% CI: 0.129-0.549), non-calcified PAV (β = 0.237, 95% CI: 0.019-0.455), and calcified PAV (β = 0.109, 95% CI: 0.019-0.200), independent of age, sex, cardiovascular risk factors, medications, and baseline PCAT attenuation and PAV (all p < 0.05). The effect of elevated PCAT attenuation on overall plaque progression was consistent across subgroups (all p for interaction > 0.05).

Conclusion: In this longitudinal CCTA cohort of T2DM patients with improved mCRFs, increased pericoronary inflammation was associated with the progression of atherosclerotic plaque, particularly non-calcified plaque.