Clinical Management and Outcomes Based on Functional Coronary Artery Disease Reporting and Data System Compared With Anatomical Coronary Artery Disease Reporting and Data System in Patients With Stable Coronary Artery Disease.

Abstract

Although anatomical Coronary Artery Disease Reporting and Data System (CAD-RADS) is widely used for coronary CT angiography reporting, it has limited specificity for predicting lesion-specific ischemia. This study evaluates whether the novel functional CAD-RADS, integrating CT-derived fractional flow reserve, provides superior 5-year prognostic value in patients with stable coronary artery disease (CAD). A single-center prospective cohort study enrolled 1,096 participants aged ≥18 years with CAD referred for CT angiography with stenosis degrees of 25% to 80%. Primary end points were major adverse cardiac events (MACEs). The appropriateness of management decisions relative to anatomical or functional CAD-RADS recommendations was explored. Statistical analyses included Kaplan-Meier estimates, Cox proportional hazards models, measures of integrated discrimination improvement, and net reclassification improvement. After a median follow-up of 64 months, 158 MACEs occurred. Both functional and anatomical CAD-RADS categories predicted MACE (P < .001). Functional CAD-RADS showed a higher C-index (0.780; 95% confidence interval [CI]: 0.764-0.796) compared with anatomical CAD-RADS (0.723; 95% CI: 0.703-0.743) for predicting MACE (P = .035), with improved discrimination (integrated discrimination improvement: 0.053 [95% CI: 0.016-0.110]; P = .008). The proportion of inappropriate management decisions was lower for functional CAD-RADS (9.9%) than for anatomical CAD-RADS (11.0%, P < .001). The hazard ratios for MACE when comparing dichotomous appropriate and inappropriate management decisions relative to functional CAD-RADS were 9.544 (95% CI: 5.794-15.720; P < .001), and 2.475 (95% CI: 1.369-4.474); P < .001) for anatomical CAD-RADS recommendations, corresponding to the number needed to treat of 1.912 (95% CI: 1.605-2.364), and 5.076 (95% CI: 3.546-10.204), respectively. Functional CAD-RADS may offer improved predictive power for moderate-term outcomes compared with anatomical CAD-RADS, suggesting potential clinical utility in guiding patient management and informing treatment algorithms for CAD, particularly in patients with intermediate stenosis.