Clinical implications of residual SYNTAX score after percutaneous coronary intervention in patients with chronic total occlusion and multivessel coronary artery disease: A comparison with coronary artery bypass grafting

Aims: In this study we sought to evaluate the clinical impact of the residual SYNTAX score (rSS) after percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) and multivessel coronary artery disease (CAD). Methods and results: We analysed data from 1, 043 patients with CTO and multivessel CAD who were treated with PCI or coronary artery bypass grafting (CABG). Patients were divided into three groups: patients with rSS≤12 after PCI (rSS≤12 group, n=445), patients with rSS>12 after PCI (rSS>12 group, n=150), and patients who underwent CABG (CABG group, n=448). We compared the incidence of cardiac death among the three groups. During a median follow-up period of 42 months, cardiac death occurred in 14 patients (3.1%) in the rSS≤12 group, 14 patients (9.3%) in the rSS>12 group, and 29 patients (6.5%) in the CABG group. On multivariate analysis, the rSS≤12 group had a significantly lower incidence of cardiac death than the rSS>12 group (hazard ratio [HR] 0.35, 95% confidence interval [CI]: 0.16 to 0.75; p=0.01), but had an incidence of cardiac death similar to that of the CABG group (HR 0.63, 95% CI: 0.32 to 1.23; p=0.17). Conclusions: An rSS≤12 after PCI may reduce the risk of cardiac mortality and could be a measure of reasonable incomplete revascularisation in patients with CTO and multivessel CAD.