SYNTAX Score and Long-Term Outcomes: The BARI-2D Trial.

Background: The extent of coronary disease affects clinical outcomes and may predict the effectiveness of coronary revascularization with either coronary artery bypass graft (CABG) surgery or percutaneous coronary intervention (PCI). The SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score quantifies the extent of coronary disease.

Objectives: This study sought to determine whether SYNTAX scores predicted outcomes and the effectiveness of coronary revascularization compared with medical therapy in the BARI-2D (Bypass Angioplasty Revascularization Investigation 2 Diabetes) trial.

Methods: Baseline SYNTAX scores were retrospectively calculated for BARI-2D patients without prior revascularization (N = 1,550) by angiographic laboratory investigators masked to patient characteristics and outcomes. The primary outcome was major cardiovascular events (a composite of death, myocardial infarction, and stroke) over 5 years.

Results: A mid/high SYNTAX score (≥23) was associated with a higher risk of major cardiovascular events (hazard ratio: 1.36, confidence interval: 1.07 to 1.75, p = 0.01). Patients in the CABG stratum had significantly higher SYNTAX scores: 36% had mid/high SYNTAX scores compared with 13% in the PCI stratum (p < 0.001). Among patients with low SYNTAX scores (≤22), major cardiovascular events did not differ significantly between revascularization and medical therapy, either in the CABG stratum (26.1% vs. 29.9%, p = 0.41) or in the PCI stratum (17.8% vs. 19.2%, p = 0.84). Among patients with mid/high SYNTAX scores, however, major cardiovascular events were lower after revascularization than with medical therapy in the CABG stratum (15.3% vs. 30.3%, p = 0.02), but not in the PCI stratum (35.6% vs. 26.5%, p = 0.12).

Conclusions: Among patients with diabetes and stable ischemic heart disease, higher SYNTAX scores predict higher rates of major cardiovascular events and were associated with more favorable outcomes of revascularization compared with medical therapy among patients suitable for CABG. (Bypass Angioplasty Revascularization Investigation in Type 2 Diabetes; NCT00006305).