Table 1_Perivascular fat attenuation index improves the identification of functional myocardial ischemia beyond traditional risk factors: a coronary CT angiography-derived fractional flow reserve study.pdf

The incremental diagnostic performance of adding FAI to a baseline clinical model was assessed using area under the receiver operating characteristic curve (AUC), continuous net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA).</p>Results<p>Despite comparable baseline profiles for low-density lipoprotein cholesterol, body mass index, and glycemic status (P > 0.05), patients in the high FAI group exhibited significantly lower CT-FFR values (0.75 ± 0.13 vs. 0.79 ± 0.12, P = 0.0017).

After adjusting for age, gender, traditional cardiovascular risk factors, and EAT volume, average FAI remained a robust independent predictor of functional ischemia [Adjusted Odds Ratio [OR]: 1.056 per 1 HU increase; 95% Confidence Interval [CI]: 1.019–1.096; P = 0.004]. Notably, EAT volume did not reach statistical significance in the multivariate model (P = 0.584). The addition of FAI to the clinical model resulted in a modest, non-significant improvement in AUC (0.731 vs. 0.707, P = 0.087), but yielded significant improvement in risk reclassification (continuous NRI: 0.339, P = 0.001; IDI: 0.024, P = 0.002).

Subgroup analysis demonstrated a consistent risk trend across varying degrees of stenosis, age, and body mass index categories (OR range: 1.03–1.07). DCA confirmed superior net clinical benefit for the FAI-integrated model across a wide threshold probability range (25%–75%).</p>Conclusions<p>Coronary perivascular FAI is an independent imaging marker for CT-FFR-defined functional ischemia and provides incremental value beyond traditional risk factors and EAT volume.

These findings support FAI as a non-invasive marker of coronary inflammation that may refine risk stratification for functionally significant coronary artery disease. However, as CT-FFR mainly reflects epicardial physiology, the association between FAI and microvascular dysfunction remains to be determined.</p>