Abstract 9334: Risk Prediction With the Anatomic Syntax Score in Patients With Left Main Coronary Artery Disease Undergoing PCI Or CABG

Background: Individualized risk prediction is central to personalized decision-making in patients with left main coronary artery disease being considered for revascularization. Purpose: To examine the prognostic performance and treatment interactions with the anatomic SYNTAX score in patients with left main disease undergoing PCI vs CABG. Methods: Individual patient data from the four major trials comparing PCI with DES to CABG in patients with left main disease (SYNTAX, PRECOMBAT, NOBLE, EXCEL) were combined. Patients were categorized by core lab-determined SYNTAX score categories (low: ≤22; intermediate: 23-32; high: ≥33). KM event rates were calculated in each treatment arm through 5 years. Hazard ratios were generated using a Cox model with trial as a random effect; absolute risk differences were calculated. Heterogeneity between randomized treatment effect and baseline score was tested. Results: 4,394 patients were randomized to PCI or CABG. The SYNTAX score identified a gradient of risk for death (~2-fold) and for major coronary events (spontaneous MI or revasc; MCE) ( Fig ). The risk gradient for MCE was only apparent after PCI and not after CABG, leading to differential absolute risk reductions with CABG from 5.5% (95%CI 2.3-8.7%) to 16.2% (11.1-21.3%) in those with low vs high SYNTAX scores (P int =0.002). There was no significant heterogeneity across SYNTAX score categories for risk of stroke, protocol-defined procedural MI, or UDMI-defined procedural MI after PCI vs CABG. Conclusion: The anatomic SYNTAX score identified risk for death and coronary events following PCI and CABG for left main disease. Mortality was similar after PCI and CABG across SYNTAX score categories. In contrast, MCE risk increased with higher SYNTAX scores after PCI but not after CABG, and the anatomic SYNTAX score thus identified high-risk patients with greater relative and absolute MCE reductions with CABG.