Impact of left ventricular ejection fraction on 10-year mortality in the SYNTAX trial

Backgrounds: The impact of reduced left ventricular ejection fraction (LVEF) on very long-term prognosis following percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) has been debated. The aim of this study was to investigate the impact of LVEF at baseline on 10-year mortality in the SYNTAX trial. Methods: Patients (n = 1800) were categorized into three sub-groups: reduced (rEF ≤ 40 %), mildly reduced (mrEF 41–49 %), and preserved LVEF (pEF ≥ 50 %). The SYNTAX score 2020 (SS-2020) was applied in patients with LVEF<50 % and ≥ 50 %. Results: Ten-year mortalities were 44.0 %, 31.8 %, and 22.6 % (P < 0.001) in patients with rEF (n = 168), mrEF (n = 179), and pEF (n = 1453). Although no significant differences were observed, the mortality with PCI was higher than with CABG in patients with rEF (52.9 % vs 39.6 %, P = 0.054) and mrEF (36.0 % vs. 28.6 %, P = 0.273), and comparable in pEF (23.9 % vs. 22.2 %, P = 0.275). Calibration and discrimination of the SS-2020 in patients with LVEF<50 % were poor, whilst they were reasonable in those with LVEF≥50 %. The proportion of patients eligible for PCI who had a predicted equipoise in mortality with CABG was estimated to be 57.5 % in patients with LVEF≥50 %. CABG was safer than PCI in 62.2 % of patients with LVEF<50 %. Conclusions: Reduced LVEF was associated with an increased risk of 10-year mortality in patients revascularized either surgically or percutaneously. Compared to PCI, CABG was safe revascularization in patients with LVEF≤40 %. In patients with LVEF≥50 % individualized 10-year all-cause mortality predicted by SS-2020 was helpful in decision-making whilst the predictivity in patients with LVEF<50 % was poor.