Association between the systemic immune‐inflammation index and outcomes among atrial fibrillation patients with diabetes undergoing radiofrequency catheter ablation

PURPOSE: To investigate the relationship between the incidence of atrial fibrillation (AF) recurrence and the levels of the systemic immune‐inflammatory index (SII, platelet × neutrophil/lymphocyte ratio) in patients with AF and diabetes mellitus (DM) undergoing after radiofrequency catheter ablation (RFCA). PATIENTS AND METHODS: Preoperative SII levels were determined in AF patients with DM undergoing RFCA. Restricted cubic splines were used to determine the correlation between SII and the risk of AF recurrence. Multivariate‐adjusted logistic regression models were constructed to determine the relationship between SII levels and AF recurrence. The predictive value of the clinical model and combined with the SII index was estimated by the area under the receiver‑operating characteristic curve, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). RESULTS: A total of 204 patients with AF and DM who underwent RFCA in our hospital were included. Seventy‐seven patients had AF recurred during a mean follow‐up of 20 months. Restricted cubic spline analysis showed that when SII ≥ 444.77 × 10(9)/L, there was a positive correlation with the incidence of AF recurrence. In addition, adding the SII to the predictive model for AF recurrence after RFCA in patients with DM and AF could contribute to an increase in C‐statistics (0.798 vs. 0.749, p = .034). After SII was incorporated into the clinical model, the comprehensive discrimination and net reclassification tended to improve (IDI and NRI > 0, p < .05). CONCLUSION: SII was independently and positively associated with recurrence after the first catheter ablation in patients with DM and AF.