Functional SYNTAX score for risk assessment in multivessel coronary artery disease

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Biomedical Engineering

Background:

• The SYNTAX score (SS) is an anatomic tool for predicting outcomes in multivessel coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI).
• Fractional flow reserve (FFR)-guided PCI enhances outcomes by integrating functional data with anatomical information.

Purpose of the Study:

• To evaluate if a functional SYNTAX score (FSS), derived from FFR, offers superior clinical outcome prediction compared to the traditional SS.
• To assess the predictive value of FSS versus SS for major adverse cardiac events (MACE) in patients with multivessel CAD undergoing PCI.

Main Methods:

• The study prospectively analyzed 497 patients from the FAME study, collecting SS data.
• FSS was calculated by considering only lesions with FFR ≤ 0.80 (ischemia-producing).
• The predictive accuracy of FSS and SS for 1-year MACE was compared using statistical models.

Main Results:

• A significant proportion (32%) of patients were reclassified to a lower-risk category based on FSS.
• 1-year MACE rates were significantly different across FSS risk groups (9.0% low, 11.3% medium, 26.7% high; p < 0.001).
• FSS demonstrated superior predictive accuracy for MACE compared to SS (Harrell's C: 0.677 vs. 0.630, p=0.02), with FSS and procedure time as independent predictors.

Conclusions:

• Incorporating FFR-defined ischemia into the SS (creating FSS) reduces the number of patients classified as high-risk.
• FSS provides better risk discrimination for adverse events in multivessel CAD patients undergoing PCI than the anatomic SS alone.