Aorta-specific fat attenuation index was significantly higher in active Takayasu arteritis compared to inactive disease, with a one-unit increase raising the odds of disease activity by 14%.
Case-Control (n=178)
Blinded image analysis
No
Does aorta-specific FAI measured via CTA assess disease activity and inflammation in patients with Takayasu arteritis?
Aorta-specific FAI derived from routine CTA provides an objective, quantifiable measure of vascular inflammation that can accurately differentiate active from inactive Takayasu arteritis.
Effect estimate: OR 1.14 (95% CI 1.02-1.28)
Absolute Event Rate: -75.51% vs -80.53%
p-value: p=0.025
Abstract Objectives Takayasu arteritis (TA) is a rare vasculitis impacting the aorta and its branches in young people, leading to severe health issues and early death. Accurate assessment of disease activity is crucial for treatment. Chronic vascular wall inflammation is a key feature of TA. The peri-coronary fat attenuation index (FAI), measured via coronary computed tomographic angiography (CTA), is a new marker for coronary inflammation and cardiovascular risk. However, the value of aorta-specific FAI for diagnosing and assessing TA activity is still uncertain. Materials and methods The study examined 101 TA patients and 77 matched controls with aortic CTA from September 2015 to May 2023. Disease activity was assessed using the Kerr score, and perivascular fat was analyzed with semi-automatic software. Aortic CTA parameters included maximal wall thickness, affected branches, luminal abnormalities, standardized CT values, and collateral branches. The primary focus was on the link between aorta-specific FAI and TA activity. Results Aorta-specific FAI was higher in active TA patients than inactive ones, with medians of −75.51 HU and −80.53 HU, respectively ( p = 0.002). FAI positively correlated with the Kerr score, aortic wall thickness, and erythrocyte sedimentation rate. A one-unit FAI increase raised TA activity odds by 14% (OR = 1.14, p = 0.025). Combining FAI with other imaging parameters improved TA activity diagnosis, reaching an AUC of 0.80. Conclusion Aorta-specific FAI from CTA can assess TA activity, enhance morphological diagnosis and improve vessel wall inflammation evaluation. Critical relevance statement This study demonstrates that the aorta-specific FAI derived from routine CTA provides an objective, quantifiable measure of vascular inflammation and disease activity in TA, enhancing the diagnostic yield of standard morphological assessment. Key Points Accurate assessment of disease activity in Takayasu arteritis remains challenging with current clinical and standard imaging criteria. Aorta-specific fat attenuation index is significantly elevated in active Takayasu arteritis and correlates with established markers of inflammation and vascular wall thickening. Combining fat attenuation index with CTA morphology enhances non-invasive diagnosis of active Takayasu arteritis, without extra cost or radiation. Graphical Abstract
Jian et al. (Mon,) conducted a case-control in Takayasu arteritis (n=178). Aorta-specific fat attenuation index (FAI) measurement vs. Inactive Takayasu arteritis was evaluated on Odds of active Takayasu arteritis per one-unit FAI increase (OR 1.14, 95% CI 1.02-1.28, p=0.025). Aorta-specific fat attenuation index was significantly higher in active Takayasu arteritis compared to inactive disease, with a one-unit increase raising the odds of disease activity by 14%.