Background Current prognostic risk scoring systems and biomarkers are routinely used as non-invasive methods for assessing late recurrence of atrial fibrillation (AF) in patients who have undergone radiofrequency catheter ablation (RFCA). This study aimed to investigate the predictive value of the triglyceride-glucose (TyG) index for late AF recurrence after RFCA in non-diabetic patients. Methods In total, 275 patients with AF who underwent RFCA at the Fuwai hospital (Beijing, China) between January 2016 and December 2018 were enrolled in this study. During follow up, patients were divided into late and non-late AF recurrence groups, based on whether they had experienced late AF recurrence determined by electrocardiography (ECG) examine or 48 h Holter monitoring. The TyG index was calculated using the following equation: ln [fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2]. Results During a median follow-up of 26.1 months, late AF recurrence event rates significantly increased in the highest TyG index tertile group (tertile 3) compared to the lowest group (tertile 1) (54% versus 12%, respectively; p < 0.001). The mean TyG index was higher in the late AF recurrence group compared to the non- late AF recurrence group (9.42 ± 0.6 versus 8.68 ± 0.70, respectively; p < 0.001). On multivariate Cox regression analysis, the pre-ablation TyG index was an independent risk factor for late recurrence of AF after RFCA (hazard ratio [HR] 2.015 [95% confidence interval (CI): 1.408–4.117]; p = 0.009). Receiver operating characteristic (ROC) curve analysis revealed that TyG index was a significant predictor of late AF recurrence after RFCA, with an area under the ROC curve (AUC) of 0.737 (95% CI: 0.657–0.816; p < 0.001). In addition, the AUC of left atrial diameter (LAD) was 0.780 (95%CI: 0.703–0.857, p < 0.001). Finally, the TyG index positively correlated with LAD (r = 0.133, p = 0.027), high sensitivity C-reactive protein (r = 0.132, p = 0.028) and N-terminal pro B-type natriuretic peptide (r = 0.291, p < 0.001) levels. Conclusions An elevated pre-ablation TyG index was associated with an increased risk of late AF recurrence after RFCA in non-diabetic patients. The TyG index may be potentially useful as a novel biomarker for the risk stratification of late AF recurrence in non-diabetic patients.

Graphical Abstract Graphical Abstract ( A ) Ventricular arrhythmias (VAs) originating around the right pulmonary sinus (PRS) in different types of inferior axis ECG. ( B ) Electrocardiographic localization of VAs with inferior axis and LBBB pattern; G1, case group; G2, non-RVOT control group; G3, RVOT control group. ( C ) Hypothesis of the longer R-wave duration during PRS-VAs in lead-V1. ( D ) The electric axis of the control and case group during sinus rhythm. Fw., free wall; LBBB, left bundle branch block; PA, pulmonary artery; RVOT/LVOT, right/left ventricular outflow tract; Sep., septum; TA/MA, tricuspid/mitral annulus.

Background Pulmonary vein (PV) reconnection after radiofrequency ablation (RFC) or 2nd generation cryoballoon (CB) pulmonary vein isolation (PVI) is common. Method We report a single-center experience of 156 patients who underwent an alternating redo procedure-ablation strategy for recurrent atrial fibrillation (AF) after a failed index RFC or CB procedure. During the redo procedure, alternating ablation technique was applied in a reverse sequence: RFC was applied for redo ablation in 60 patients with failed index CB ablation(CB-RFC-redo); 2nd generation CB was used for redo ablation in 96 patients after failed index RFC ablation (RFC-CB redo); Results During the redo procedure, the proportion of patients with PV reconnection was lower after index CB PVI procedure compared with the proportion of patients after index RFC PVI (88.3% versus 98.9%, p = 0.01). Additionally, 82.8% of all PVs and left common trunks PV (CTs) isolated by index RFC were reconnected, compared with 42% PVs reconnected after index CB PVI (p = 0.005). A mean number of 1.50 ± 0.8 PVs /patient were reconnected after index CB PVI, compared with 3.36 ± 0.9 PVs /patient after index RFC PVI (p = 0.001). Patients after index RFC PVI frequently presented with ≥ 3 reconnected PVs, compared with index CB PVI(70.8% vs 10%, p < 0.001). A total of 60 patients after index CB PVI underwent RFC-redo ablation, and 96 patients after index RFC PVI underwent CB-redo ablation. At a two year follow-up, 43 patients (27.6%) developed recurrence after redo ablation, with a similar AF- free outcome (CB-RFC redo:73.3% vs RFC-CB redo: 71.9%, p = 0.873). In the multivariate analysis, persistent AF (HR = 2.107, 95% CI: 1.085–4.091, p = 0.028) and early AF recurrence after the initial ablation (HR = 2.431, 95% CI: 1.279–4.618, p = 0.007) were independent predictors of AF recurrence after repeat ablation. Conclusions The extent and distribution of PV reconnections were different after index RFC and CB PVI procedures. Alternating CB or RFC ablation technique strategy is effective with a similar long-term outcome, and it may be an appropriate option for repeated AF ablation regardless of index ablation technique used.