Prognostic Implication of a CT-FFR-Based Functional SYNTAX Score in Coronary Artery Disease Patients Undergoing Percutaneous Coronary Intervention

Background: This study aims to investigate the value of a SYNTAX score (SS) based on coronary computed tomographic angiography (cCTA)-derived fractional flow reserve (CT-FFR), termed “Functional SYNTAX score” (FSSCTA), to predict major adverse cardiovascular events (MACEs) in patients undergoing percutaneous coronary intervention (PCI). Methods: This cohort study included 876 patients who underwent cCTA and underwent PCI within 30 days during 2016–2020. CT-FFR was calculated by a machine learning algorithm. All 876 patients were divided into a low-risk group (≤22) and an intermediate-to-high-risk group (>22) with cCTA-based SS (SSCTA) as the control. Results: Based on the FSSCTA, 10.4% (91/876) of patients were reclassified to the low-risk group, and 2.9% (25/876) of patients were reclassified to the intermediate-to-high-risk group. MACEs occurred in 16.6% (145/876) of patients over a median follow-up period of 19.4 months. FSSCTA and invasive coronary angiography-based SS (SSICA) were independently associated with the risk of MACEs regardless of whether they were in continuous or categorical form (FSSCTA: c continuous HR 1.082, 95% CI 1.038–1.128; categorical HR 1.865, 95% CI 1.138–2.305. SSICA: continuous HR 1.045, 95% CI 1.012–1.079; categorical HR 1.520, 95% CI 1.128–2.048). FSSCTA showed the best predictive power for MACEs compared with SSCTA and SSICA (all comparisons with FSSCTAp < 0.05). Conclusions: FSSCTA, SSCTA and SSICA were all independent predictors of MACEs in patients undergoing PCI, and FSSCTA showed a significantly better predictive value for MACEs than SSCTA and SSICA.