Added prognostic value of fat attenuation index and CT-derived fractional flow reserve over plaque burden in suspected CAD patients without standard modifiable risk factors.

BACKGROUND

In this study, we aimed to investigate the added prognostic value of fat attenuation index (FAI) and CT-derived fractional flow (CT-FFR) over plaque burden in suspected coronary artery disease (CAD) patients without standard modifiable risk factors (SMuRFs).

METHODOLOGY

A total of 260 consecutive suspected CAD subjects without SMuRFs who underwent first coronary computed tomography angiography (CCTA) were retrospectively collected. We calculated FAI, CT-FFR, and segment involvement score (SIS) from CCTA images. Cox regression models were used to assess the incremental prognostic value of FAI and CT-FFR.

RESULTS

During a median follow-up of 25.00 months, major adverse cardiovascular events (MACE) were observed in 40 (15.4%) patients. FAI ≥ -70.1, CT-FFR ≤ 0.80, and SIS ≥ 4.5 were associated with the increased rate of MACE ( < 0.0001). FAI did not provide incremental prognostic value over SIS ( = 0.169). Likewise, CT-FFR did not enhance risk prediction ( = 0.159). Combining FAI and CT-FFR added incremental prediction value and improved risk discrimination ( = 0.032; Absolute integrate discrimination improvement (IDI) = 0.070, < 0.001).

CONCLUSION

In suspected CAD patients without SMuRFs, neither FAI nor CT-FFR independently added incremental prognostic value over plaque burden. Combining FAI and CT-FFR had added prognostic value and improved cardiovascular risk stratification.