Abstract Background and Objectives This study aimed to explore the correlation between free fatty acid (FFA) levels and adverse outcomes in patients undergoing percutaneous coronary intervention (PCI) with or without diabetes mellitus. Methods In total, 10,230 patients treated with PCI were included in this study and divided into three equal groups according to FFA levels (FFA-L, FFA-M, and FFA-H groups). Subsequently, the patients were further stratified based on their diabetes status. A 5-year follow-up was conducted, with the primary endpoint defined as major adverse cardiovascular and cerebrovascular events (MACCE). Results During follow-up, 2108 (20.6%) patients experienced MACCE. In patients without diabetes, no significant difference was observed in the risk of MACCE among the different FFA groups. However, in patients with diabetes, the risk of MACCE was significantly higher in the FFA-L and FFA-H groups than in the FFA-M group adjusted hazard ratio (HR), 1.238, 95% confidence interval (CI), 1.054–1.454, P = 0.009; adjusted HR: 1.220, 95% CI, 1.054–1.412, P = 0.008; respectively. The restricted cubic spline curves showed a nonlinear U-shaped relationship between the FFA levels and the risk of MACCE in patients with diabetes, with the lowest risk observed at an FFA level of 372 μmol/L. The results of the subgroup analysis stratified by different clinical presentations and BMI were similar to those of the primary findings. Conclusions In patients with diabetes undergoing PCI, both elevated and decreased FFA levels were significantly associated with an increased risk of MACCE. Monitoring FFA levels is essential to help identify those at high risk.
Li et al. (2026) studied this question.