Percutaneous coronary intervention (PCI) of bifurcation lesions is associated with higher rates of adverse events. Whether coronary artery bypass grafting (CABG) or PCI is a safer revascularization modality for bifurcation lesions remains to be elucidated. The SYNTAX score II 2020 (SSII-2020) can be used to individualize the prediction of all-cause mortality at 10-year after CABG or PCI. The present study is a subgroup analysis of the SYNTAXES, (The SYNTAX Extended Survival, NCT 03417050)  an investigator-driven extended 10-year follow-up of the SYNTAX trial; the impact of bifurcation lesions on individual predicted and observed all-cause 10-year mortality was investigated in patients with 3VD and/or LMCAD undergoing PCI or CABG.

Patients were categorized in four groups: (a) presence of ≥1bifurcation lesion and treatment with PCI, (b) no bifurcation lesion and treatment with PCI, (c) presence of ≥1bifurcation lesion and treatment with CABG, and (d) no bifurcation lesion and treatment with CABG. The primary endpoint was all-cause mortality at 10-year.

In patient receiving PCI, compared to those without a bifurcation lesion, those with bifurcation lesion(s) had a significantly higher risk of all-cause death (19.8% vs 30.1%; HR: 1.55, 95% CI: 1.12-2.14; p=0.007), whereas following CABG, mortality was similar in patients with or without bifurcation lesion(s) (23.3% vs 23.0%; adjusted HR: 0.81, 95% CI: 0.59-1.12; p=0.207). There was a significant interaction between bifurcation lesion(s) and the treatment effect of PCI versus CABG on mortality (p for interaction =0.006). Of note, a landmark analysis in patients with bifurcation lesions treated with PCI, shows a continuous and significant divergence of cumulative mortality beyond 5-year (Figure 1).At 5-year, all-cause death was similar between patients treated with a 2-stent compared to a 1-stent technique (15.0% vs 13.4%, adjusted HR:1.13; 95%CI: 0.68-1.88; p=0.642), whereas at 10-year, use of a 2-stent technique was an independent predictor of all cause death after adjustment (33.3% vs 25.9%; adjusted HR:1.51; 95%CI: 1.06-2.14; p=0.021).According to the SSⅡ-2020, 22.7% of the randomized population with a bifurcation lesion had an ARD in mortality between PCI and CABG of zero. When the Credo Kyoto cut-off criteria of an ARD<4.5% was used, 48.1% of the population (with or without bifurcation) could legitimately undergo PCI (Figure 2).

Bifurcation lesion(s) require specific consideration by the Heart team when deciding between PCI and CABG, as a consequence of their higher associated all-cause mortality following PCI. Notwithstanding this, the average treatment effect can be mitigated by calculating an individualized 10-year vital prognosis using the SSII-2020.