Prognostic Value of Anatomical SYNTAX Score and SYNTAX Score II in Veterans With Left Main and/or Three-Vessel Coronary Artery Disease

Abstract

Anatomical SYNTAX score (SS1) and SYNTAX score II (SS2) are often utilized to determine the optimal revascularization strategy. Although US veterans have unique characteristics that may affect outcomes after revascularization, the prognostic values of SS1 and SS2 in veterans have not yet been validated. We performed a retrospective analysis of consecutive veteran patients who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for left main and/or 3-vessel disease from 2009 to 2014. SS1 and SS2 were calculated for each patient. The primary outcome was all-cause mortality. The prognostic values of SS1 and SS2 were compared by receiver operating characteristic curve analysis. The predicted 4-year mortality derived from SS2 was compared with the observed 4-year mortality estimated from Kaplan-Meier analysis. After exclusion, 286 patients (99% male) were included. Among 286 patients, 79 patients (27.6%) had left main disease, 151 (52.8%) underwent PCI, and 135 (47.2%) underwent CABG. Overall mortality was 27.6% at a median follow-up of 5.0 years. SS2 had better discriminative ability for all-cause mortality than SS1 (c-index 0.79 vs 0.52, p <0.001). Observed and predicted 4-year mortality correlated well in patients with low and intermediate SS2 in both PCI and CABG cohorts, but observed mortality was higher than predicted in the PCI cohort with high SS2 (observed 54.7% vs predicted 40.5%). In conclusion, observed and predicted 4-year mortality derived from SS2 correlated well in patients with low and intermediate SS2, but SS2 underestimated mortality in the PCI cohort with high SS2.