Role of Preablation Neutrophil/Lymphocyte Ratio on Outcomes of Cryoballoon-Based Atrial Fibrillation Ablation

The neutrophil/lymphocyte ratio (NLR) has recently emerged as better indicator of inflammation and oxidative stress and has been widely studied in several cardiovascular diseases. In the present study, we evaluated the role of the preablation NLR in atrial fibrillation (AF) recurrence after cryoballoon-based catheter ablation. A total of 251 patients (47.8% women, age 54.12 ± 10.9 years, 80.1% with paroxysmal AF) with symptomatic AF underwent cryoablation. At a mean follow-up of 19.0 ± 6.6 months, 60 patients (23.9%) had developed AF recurrence. The patients who developed AF recurrence had had a greater preablation NLR (3.53 ± 0.95 vs 2.65 ± 0.23, p <0.001) and a higher white blood cell count, neutrophil count, and high-sensitivity C-reaction protein levels. On multivariate regression analysis, the preablation NLR (hazard ratio 2.15, 95% confidence interval 1.70 to 2.73, p <0.001), left atrial diameter (hazard ratio 1.09, 95% confidence interval 1.04 to 1.14, p <0.001) and early AF recurrence (hazard ratio 2.99, 95% confidence interval 1.71 to 5.23, p <0.001) were independent predictors of AF recurrence after cryoablation. Using a cutoff level of 3.15, the preablation NLR predicted AF recurrence during follow-up with a sensitivity of 84% and specificity of 75%. Patients with a preablation NLR >3.15 had a 2.5-fold increased risk of developing AF recurrence after cryoablation. In conclusion, an elevated preablation NLR was associated with increased AF recurrence after cryoballoon-based catheter ablation. Our results support the role of a preablation inflammatory environment in the development of AF recurrence after ablation therapy but suggest that other factors are also important.