Prognostic Value of SYNTAX Score II in Patients with Acute Coronary Syndromes Referred for Invasive Management: A Subanalysis from the SPUM and COMFORTABLE AMI Cohorts

Aims: To assess the incremental prognostic value of SYNTAX score II (SxSII) as compared to anatomical SYNTAX Score (SxS) and GRACE risk score in patients with acute coronary syndromes who underwent percutaneous coronary intervention. Methods and results: SxSII and SxS were determined in 734 ACS patients. Patients were enrolled in the prospective Special Program University Medicine ACS and the COMFORTABLE AMI cohorts and later on stratified according to tertiles of SxSII (SxSIILow </=21.5 (n=245), SxSIIMid 21.5-30.6 (n=245), and SxSIIHigh >/=30.6 (n=244). The primary endpoint of adjudicated all-cause mortality and secondary endpoints of MACE (cardiac death, repeat revascularization, and myocardial infarction) and MACCE (all-cause mortality, cerebrovascular events, MI, and repeat revascularization) were determined at 1-year follow-up. SxSII provided incremental predictive information for risk stratification when compared to SxS and GRACE risk score (AUC 0.804, 95% CI 0.77-0.84, p < 0.001 versus 0.67, 95% CI 0.63-0.72, p=0.007 versus 0.69, 95% CI 0.6-0.8, p=0.002), respectively. In a multivariable Cox regression analysis, we found that unlike SxS (adjusted HR 1.013, 95% CI (0.96-1.07), p=0.654), SxSII was significantly associated with all-cause mortality (HR = 1.095, 95% CI (1.06-1.11), p < 0.001). This was also true for the prediction of both secondary outcomes MACE (n=60) and MACCE (n=70) with an adjusted HR = 1.055, 95% CI (1.03-1.08), p < 0.001, and HR = 1.065, 95% CI (1.04-1.09), p < 0.001. Conclusion: In patients with ACS who underwent PCI, SxSII is an independent predictor of mortality during 1-year follow-up. SxSII shows superiority in discriminating risk compared to conventional SxS and GRACE for all-cause mortality.