Incremental prognostic value of pericoronary fat attenuation index in diabetic patients with non-obstructive coronary artery disease

Non-obstructive coronary artery disease (CAD) is highly prevalent in diabetic patients, yet there are currently limited evidence-based recommendations for risk stratification and management in this population. We aimed to investigate the additional prognostic value of pericoronary fat attenuation index (FAI) beyond coronary computed tomography angiography (CCTA) parameters and CCTA-derived fractional flow reserve (CT-FFR) in diabetic patients with non-obstructive CAD. 310 diabetic patients with non-obstructive CAD (coronary stenosis 1–49% on CCTA) between January 2017 and December 2018 were retrospectively enrolled. Clinical data, CCTA parameters, CT-FFR, and pericoronary FAI of patients were collected. Major adverse cardiovascular events (MACE) included rehospitalization for unstable angina, non-fatal myocardial infarction, late coronary revascularization, and cardiac death. During a median follow-up of 71 (65, 78) months, 35 patients experienced MACE. Multivariate Cox regression analysis showed that high-risk plaque (HRP) [hazard ratio (HR) = 4.323; 95% confidence interval (CI): 1.978–9.451; p < 0.001], CT-FFR ≤ 0.80 (HR = 2.622; 95% CI: 1.021–6.732; p = 0.045), and pericoronary FAI > − 73.87 HU (HR = 5.074; 95% CI: 2.191–11.751; p < 0.001) were independent predictors of MACE. Adding pericoronary FAI to the model including HRP and CT-FFR significantly improved area under the curve from 0.665 to 0.783 (p = 0.006). Similar results were observed when major adverse cardiovascular and cerebrovascular events were used for sensitivity analysis. Pericoronary FAI was an independent predictor of MACE in diabetic patients with non-obstructive CAD, and it provided incremental prognostic value beyond HRP and CT-FFR.