Abstract
OBJECTIVE: The purpose of this study was to explore the connection between the C-reactive protein to albumin ratio (CAR) and major adverse cardiac events (MACE) in individuals with stable coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). METHODS: This study employed a retrospective cohort design and involved 196 individuals who had recently been diagnosed with stable CAD and received elective PCI. Participants were categorized into four groups according to their CAR quartiles, with the lowest quartile (Q1) serving as the reference group. The primary endpoint was MACE, which was defined as a combination of all-cause mortality, non-fatal myocardial infarction, and non-fatal stroke. To evaluate the association between CAR and MACE, multivariable Cox regression, Kaplan-Meier survival analysis, and restricted cubic spline analyses were utilized. RESULTS: Among the 196 participants (average age, 72.85 ± 10.11 years), 27 (13.78%) experienced MACE during an average follow-up period of 742 days. The rate of MACE rose significantly across the CAR quartiles (Q1: 8.16%, Q2: 6.12%, Q3: 8.16%, Q4: 32.65%; p < 0.001). In the multivariable analysis, compared to patients in the lowest CAR quartile (Q1), those in the highest quartile (Q4) had a significantly increased risk of MACE (Model 3: HR = 4.87, 95% CI: 1.40-16.95, p = 0.013). A notable nonlinear relationship was observed between CAR and MACE, with an inflection point at 0.030. Analyses of subgroups indicated a persistent association between increased CAR and MACE across all evaluated strata, with no significant interactions found (all P interaction > 0.05). CONCLUSIONS: Among patients with stable CAD who received PCI, a nonlinear association was found between CAR and MACE.