Comparison of clinical outcomes after coronary artery bypass grafting using stratified SYNTAX scores

Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are common procedures for managing coronary artery disease (CAD); however, optimal methods of comparing post-procedure outcomes are unclear. We evaluated the reliability of Synergy between percutaneous coronary intervention with Taxus and cardiac surgery (SYNTAX) scores and investigated differences in long-term outcomes after CABG among groups with different SYNTAX scores.

According to patient selection criteria used in the SYNTAX trial, 368 patients who underwent isolated initial CABG between 2003 and 2014 at Kurashiki Central Hospital were stratified into three SYNTAX score I groups (low: < 23, intermediate: 23 to < 33, and high: ≥ 33) and three SYNTAX score II groups (low: < 30, intermediate: 30 to < 40, and high: ≥ 40). Group outcomes were compared. Overall 4-year mortality data for SYNTAX score II were compared with the cohort data.

There were no significant differences in all-cause death, 10-year major adverse cardiac and cerebrovascular events (MACCEs), myocardial infarction, and stroke data in the SYNTAX score I groups. As SYNTAX score II increased, all-cause death and MACCEs rates rose significantly. Four-year mortality at our facility was 11.0 ± 1.7%, whereas that predicted by SYNTAX score II was 12.0 ± 11.1%. The predicted data were close to the clinical data, but not statistically significant, with an area under the curve of 0.769.

SYNTAX score II demonstrated reasonable predictive performance for outcomes after CABG, whereas SYNTAX score I did not. With SYNTAX score systems, treatment options should be discussed with a heart team to achieve better outcomes.