Predictive value of the C-reactive protein–triglyceride–glucose index for late atrial fibrillation recurrence after radiofrequency catheter ablation: a retrospective cohort study

Background The C-reactive protein–triglyceride–glucose index (CTI) has been reported to be positively associated with cardiovascular disease, stroke, and other adverse outcomes. However, the association between CTI and late atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) has not been well established. Methods A total of 591 patients with AF who underwent RFCA were retrospectively enrolled. CTI was calculated using triglycerides, fasting plasma glucose, and C-reactive protein. The primary endpoint was late AF recurrence during postoperative follow-up. The association between CTI and late AF recurrence after RFCA was assessed using restricted cubic spline (RCS) analysis and univariate and multivariable logistic regression analyses. Receiver operating characteristic curve analysis and the DeLong test were conducted to assess the predictive performance of CTI. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were adopted to evaluate its incremental predictive value. The Hosmer–Lemeshow test and Bootstrap-calibrated curves were used to verify model calibration and goodness-of-fit. Subgroup analyses were conducted to examine potential variations in the association between CTI and AF recurrence across subgroups. Subgroup analyses were conducted to examine potential variations in the association between CTI and AF recurrence across subgroups. Results All patients were followed for 1 year postoperatively, during which 92 cases of AF recurrence were documented. Higher CTI levels were positively associated with an increased risk of AF recurrence. RCS analysis suggested that the nonlinear test did not reach statistical significance (p for non-linear = 0.072), while a trend toward nonlinearity was observed, which may be explained by the limited number of outcome events. After multivariable adjustment, CTI remained independently and positively associated with AF recurrence, with an odds ratio of 6.20 per one-unit increase in CTI (95% CI: 3.56–10.77; p < 0.001). Subgroup and interaction analyses yielded findings consistent with the primary results. Conclusions CTI was identified as a potentially valuable predictive indicator for late AF recurrence following RFCA.