The utility of adding information on 1,5-anhydro-d-glucitol (1,5-AG), a marker for postprandial hyperglycemia, to a pre-existing scoring system in acute coronary syndrome (ACS) patients is unknown. This retrospective cohort study included 266 ACS patients. The end point was major adverse cardiac and cerebral events (MACCE) through 5 years of follow-up. To evaluate incremental benefits of combining 1,5-AG with the syntax score, we applied time-dependent receiver operating curve (ROC) analysis, net reclassification improvement (NRI), integrated discrimination improvement (IDI) and decision curve analysis (DCA). Temporal changes to the area under time-dependent ROC curves showed that addition of 1,5-AG parameters to syntax score did not provide any incremental value (area under the curve for syntax alone, 0.673 (95% confidence interval (CI), 0.599–0.747) vs. with 1,5-AG combined, 0.671 (95%CI 0.596–0.746; Delong p = 0.65). Incorporating 1,5-AG into syntax score yielded a significant NRI of 0.291 (95%CI 0.015–0.567) and IDI of 0.055 (95%CI 0.018–0.093), while DCA analysis showed the limited net benefit in combination with 1,5-AG and syntax score. 1,5-AG values exhibited significant discriminatory utility for detecting MACCE within the ACS population. However, 1,5-AG levels contributed limited utility beyond syntax score based on time-dependent ROC and DCA analyses.

Trial registration: UMIN000023837.