Prognostic Value of Quantitative Flow Ratio Combined with SYNTAX Scores I/II in Multivessel Coronary Artery Disease: A Small-Sample, Single-Center Study

Background: A fractional flow reserve (FFR)-fixed-SYNTAX score could decrease the number of high-risk patients. This study explored the prognostic value of non-invasive quantitative flow ratio (QFR)-fixed-SYNTAX I/II scores in multivessel disease patients.Methods: This was a single-center, small-sample, observational study. Multivessel coronary disease patients were enrolled and finished a 1-year follow-up. SYNTAX scores I/II and functional SYNTAX scores I/II based on QFR (cut-off value of 0.85) were calculated for all patients. The composite occurrence of cardiac deaths, any myocardial infarction, or ischemia-driven revascularization were analyzed using a different score system.Results: A total of 160 patients were stratified into risk groups based on a different scoring system. FSS (functional SYNTAX score) and FSSII (functional SYNTAX score II) reduce the radio of high-risk major adverse cardiovascular events (MACEs), transforming the patients from high-risk to medium- and low-risk. Furthermore, FSSII (hazard ratio (HR): 1.069, 95% CI: 1.025-1.115, p = 0.002) showed a better relationship with MACEs than the other score systems. After recalculating SSII, the survival-free ratio stratified by FSSII decreased from 38.46% to 27.27% in the high-risk group and increased from 84.09% to 86.05% in the low-risk group.Conclusions: FSS or FSSII could decrease the number of high-risk patients compared to SYNTAX score (SS) and FSS. SYNTAX II score (SSII) and FSSII showed a better predictive ability than other scoring systems for under-risk stratification.