145 Syntax scores and real world revascularization patterns

Abstract

The extent of coronary artery disease (CAD), defined by left main, single-, versus, double-, versus tripple-vessel disease (3VD), was the most influential factor associated with the choice of revascularization strategy [percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG)] in the Variation in Revascularization Practice in Ontario (VRPO) project (CCS 2010). Significant variation in revascularization strategies within CAD subgroups (i.e. multi-vessel disease) exist between centres. We hypothesized that variability in the complexity and severity of 3VD, as determined by the SYNTAX score, further contributes to the variation in revascularization pattern. The SYNTAX score-3VD angiographic sub-study of the VRPO project evaluated all 3VD coronary angiograms from the 1787 angiograms randomly selected from the 17 participating cardiac centers. Core lab assessment of the angiographic images was performed using the on-line SYNTAX score calculator. The primary objective was to demonstrate the mean and median SYNTAX scores as per the categorization of the 17 centres into PCI: CABG ratio groups (low <2, low-moderate 2-2.66, moderate-high 2.67-3.24, and high >3.24) in the VRPO study. Secondary objectives include the SYNTAX score's ability to predict the revascularization strategy within 90 days of the index angiogram and clinical outcomes (death and acute myocardial infarction, AMI) at 3 years. Syntax scores were calculated for all 203 3VD angiograms. There were no significant differences in the mean (median) SYNTAX scores across all 4 PCI: CABG ratio groups in the VRPO study [low: 26.3 (25.3), low-moderate: 25.9 (24.5), moderate-high: 25.7 (23.8), and high; 26.7 (26.0)]. However, the highest PCI:CABG group had the highest proportion of moderate and high SYNTAX scores (>22) (low: 62%, low-moderate: 57%, moderate-high: 53%, and high: 63%). Adjusted hazard ratio model demonstrates that the SYNTAX score predicts the revascularization strategy (PCI: HR 0.94, 95% CI 0.91-0.96 and CABG: 1.04, 95% CI 1.02-1.06). Furthermore, the SYNTAX score was associated with death but not AMI at 3 years (HR 1.03, 95% CI 1-1.07 and HR 1.01, 95% CI 0.96-1.06, respectively). While the SYNTAX score does predict the revascularization strategy, there are no significant differences in the mean and median SYNTAX scores between the 4 PCI:CABG ratio groups in the VRPO study. Furthermore, both high and low PCI:CABG ratio centres have the highest proportion of patients with complex anatomy. Therefore, the complexity and severity of 3VD does not seem to uniformly influence management strategies across all cardiac centres in Ontario.