Clinical Outcomes Based on Coronary Computed Tomography-Derived Fractional Flow Reserve and Plaque Characterization

Coronary computed tomography angiography (CTA) followed by computed tomography angiography-derived fractional flow reserve (FFR_CT) is now commonly used for the management of chronic coronary syndrome (CCS). CTA-verified high-risk plaque (HRP) characteristics have also been reported to be associated with a greater likelihood of adverse cardiac events but have not been used for management decisions.

The aim of this study was to evaluate clinical outcomes based on a combination of point-of-care computed tomography angiography-derived fractional flow reserve (POC-FFR_CT) and the presence of HRP in CCS patients initially treated medically or with revascularization based on invasive coronary angiography findings.

CTA was performed as the initial test in 5,483 patients presenting with CCS between September 2015 and December 2020 followed by invasive coronary angiography and revascularization as necessary. POC-FFR_CT assessment and HRP characterization were obtained subsequently in 745 consecutive patients. We investigated how HRP and POC-FFR_CT, which were not available during the original clinical decision making, correlated with the endpoint defined as a composite of cardiac death, acute coronary syndrome, and a need for unplanned revascularization.

Cardiac events occurred in 20 patients (2.7%) during a median follow-up of 744 days. The event rate was significantly higher in patients with POC-FFR_CT <0.80 compared with POC-FFR_CT ≥0.8 (5.4 vs 0.5 per 100 vessel years; log-rank P < 0.0001) and in patients with HRP compared to those without HRP (3.6 vs 0.8 per 100 vessel years; log-rank P = 0.0001). POC-FFR_CT <0.80 and the presence of HRP were the independent predictors of cardiac events (HR: 16.67; 95% CI: 2.63-105.39; P = 0.002) compared with POC-FFR_CT ≥0.8 and absent HRP. For the vessels with POC-FFR_CT <0.80 and HRP, a significantly higher rate of adverse events was observed in patients who did not undergo revascularization compared with those revascularized (16.4 vs 1.4 per 100 vessel years; log-rank P = 0.006).

POC-FFR_CT <0.80 and the presence of HRP were the independent predictors of cardiac events, and revascularization of HRP lesions with abnormal POC-FFR_CT was associated with a lower event rate.