The SYNTAX score is correlated with long-term outcomes of coronary artery bypass grafting for complex coronary artery lesions

Abstract

Objectives: We analysed retrospectively the long-term outcomes of conventional coronary artery bypass grafting (CABG) as employed routinely for complex coronary lesions by observing patients with low (0-22), intermediate (23-32) and high (≥33) SYNTAX scores. The purpose of this study was to evaluate the correlation between the SYNTAX score and long-term major adverse cardiac and cerebrovascular events (MACCEs) including all-cause death, stroke, myocardial infarction (MI) and repeat revascularization after CABG.

Methods: The study enrolled 396 consecutive patients with stable and untreated left main and/or three-vessel disease, who had been referred to our heart team from 2000 through 2009. They all routinely underwent conventional CABG. The three groups (low score; n = 159, intermediate score; n = 150, high score; n = 87) were compared, looking at the primary endpoint of MACCE and its components. We also analysed the effects of diverse variables on long-term MACCEs after the operation.

Results: The cumulative 10-year MACCE rates in patients with low, intermediate and high SYNTAX score were 25.3, 35.8 and 48.1%, respectively. The Kaplan-Meier cumulative event curves showed a significantly higher MACCE rate after CABG in patients with a higher SYNTAX score than in those with a lower score (log-rank P = 0.0012). This was mainly because of a significantly increased rate of repeat revascularization in the higher SYNTAX score group (log-rank P = 0.0032). The cumulative rate of repeat revascularization at 10 years in patients having low, intermediate and high SYNTAX score were, respectively, 4.6, 15.7 and 16.8%. The cumulative rates of the combined outcomes of death/stroke/MI at 10 years did not show statistical differences between the three groups (22.3% with low, 25.0% with intermediate and 38.4% with high score, log-rank P = 0.063). In the multivariable analysis, the SYNTAX score [hazard ratio (HR) 1.03, P = 0.0043] and logistic EuroSCORE II (HR 1.34, P = 0.0012) were found to be significant predictors of long-term MACCEs.

Conclusions: The SYNTAX score is correlated with long-term outcomes, in terms of MACCEs, after conventional CABG for complex coronary lesions and is prognostic of long-term outcomes of CABG for patients with complex lesions.

Keywords: Complex coronary artery lesions; Coronary artery bypass grafting; Long-term outcomes; Major adverse cardiac and cerebrovascular event; Risk factor analysis; SYNTAX score.