121Clinical impact of residual SYNTAX score after physiology guided state-of-art PCI in 3VD: insight from the SYNTAX II trial

Background The clinical implication of residual SYNTAX score in patients treated with state-of- art PCI including hybrid iFR-FFR for three vessel disease is undetermined. Purpose The purpose of this study was to investigate the clinical impact of residual SYNTAX Score (rSS) after hybrid iFR-FFR guided state-of-art PCI in patients with three vessel disease (3VD). Methods The SYNTAX-II study was a multicentre, single arm study that investigated the impact of the state-of-art PCI strategy on clinical outcomes in 454 patients with de novo 3VD, without left main disease. All the patients treated with the state-of-art PCI in the SYNTAX II trial were retrospectively screened and analysed for rSS. The rSS was defined as the SYNTAX Score (SS) recalculated after PCI. The state-of-art PCI strategy included: heart team decision-making utilizing the SYNTAX score II, hybrid iFR-FFR decision-making strategy, intravascular ultrasound guided stent implantation, contemporary chronic total occlusion revascularization techniques and guideline-directed medical therapy. The primary endpoint of this substudy was major adverse cardiac and cerebrovascular events (MACCE – a composite of all-cause death, any stroke, myocardial infarction, or revascularization) at 2 years. Patients with rSS were stratified according to angiographically complete revascularization (rSS of 0) and previously proposed rSS cut-off value of 8 (>0 to 8, and >8). Results A total of 454 patients were screened and rSS were analysable in 441 patients (97.1%). Before PCI, anatomical SS was 20.3±6.4 which was after PCI reduced to 3.9±4.5 (rSS). Only 67 patients (15.2%) had rSS >8 (mean 12.3±4.1). Two-year MACCE occurred in 58 patients (13.2%). Patients with MACCE had similar rSS to those without MACCE (2.0 (IQR: 0.0 to 6.0) vs. 2.0 (IQR: 0.0 to 5.0), p=0.313). Kaplan-Meier analysis showed similar 2- year incidence of MACCE with rSS stratifications (rSS of 0 (n=140): 15.0%, >0 to 8 (n=234): 12.0%, >8 (n=67): 13.4%, log-rank p for overall = 0.703). Conclusion After hybrid iFR-FFR guided state-of-art PCI in 3VD, residual SYNTAX Score was very low, suggesting that complete or reasonable incomplete revascularization was achieved in majority of cases. Previously proposed rSS cut-off value of 8 was not associated with a worse clinical outcome. Acknowledgement/Funding European Cardiovascular Research Institute (ECRI) with unrestricted research grants from Volcano and Boston Scientific