SYNTAX Score in Patients With Diabetes Undergoing Coronary Revascularization in the FREEDOM Trial.

BACKGROUND: Diabetes mellitus (DM) is associated with complex coronary artery disease (CAD), which in turn results in increased morbidity and mortality from cardiovascular disease.

OBJECTIVES: This study sought to evaluate the utility of SYNTAX score (SS) for predicting future cardiovascular events in patients with DM and complex CAD undergoing either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI).

METHODS: The FREEDOM (Future REvascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease) trial randomized patients with DM and multivessel CAD to undergo either PCI with drug-eluting stents or CABG. The SS was calculated retrospectively by a core laboratory. The endpoint of hard cardiovascular events (HCE) was a composite of death from any cause, nonfatal myocardial infarction, and nonfatal stroke, while the endpoint of major adverse cardiac and cerebrovascular events (MACCE) was a composite of HCE and repeat revascularization.

RESULTS: A total of 1,900 patients were randomized to PCI (n = 953) or CABG (n = 947). The SS was considered an independent predictor of 5-year MACCE (hazard ratio per unit of SS: 1.02; 95% confidence interval: 1.00 to 1.03; p = 0.014) and HCE (hazard ratio per unit of SS: 1.03; 95% confidence interval: 1.01 to 1.04; p = 0.002) in the PCI cohort, but not in the CABG group. There was a higher incidence of MACCE in PCI patients with low, intermediate, and high SS compared with those who underwent CABG (36.6% vs. 25.9%, p = 0.02; 43.9% vs. 26.8%, p < 0.001; 48.7% vs. 29.7%, p = 0.003, respectively).

CONCLUSIONS: In DM patients with multivessel CAD, the complexity of CAD evaluated by the SS is an independent risk factor for MACCE and HCE only in patients undergoing PCI. The SS should not be utilized to guide the choice of coronary revascularization in patients with DM and multivessel CAD. (Comparison of Two Treatments for Multivessel Coronary Artery Disease in Individuals With Diabetes [FREEDOM]; NCT00086450).