Prediction of mid-term outcome after cryo-balloon ablation of atrial fibrillation using post-procedure high-sensitivity troponin level

OBJECTIVE: High-sensitivity troponin I (hsTnI) assays lead to, among other things, improvement in the detection of myocardial injury and improved risk stratification of patients with atrial fibrillation (AF). The aim of this study was to investigate the association between post-procedure cardiac biomarkers and clinical outcome in patients undergoing cryo-balloon ablation (CA) for AF. METHODS: A total of 57 patients (mean age 55.1 ± 12.2 years, 50.9% female) with symptomatic paroxysmal AF underwent the CA procedure. Two hundred and twenty-eight pulmonary veins (PVs) were attempted for pulmonary vein isolation (PVI) with a second-generation cryo-balloon. hsTnI, CK-MB mass and myoglobin samples were prospectively obtained before and 24 hours after ablation. RESULT: At a mean follow up of 214.6 ± 24.3 days, the probability of being arrhythmia free after a single procedure was 86%. Post-ablation hsTnI (p = 0.001), left atrial (LA) diameter (p = 0.002), duration of AF (p = 0.002), mean minimal temperature of the left superior pulmonary vein (p = 0.005), and age (p = 0.021) were associated with increased AF recurrence rate. On multivariate analysis, lower hsTnI level was the only independent predictor for AF recurrence (p = 0.012). Post-ablation hsTnI levels lower than 4.40 ng/ml predicted AF recurrence during follow up, with a sensitivity of 86% and a specificity of 96%. CONCLUSION: It is well recognised that the PV antrum contributes to initiation and/or perpetuation of AF. A lower postablation hsTnI level may predict an increased AF recurrence rate, suggesting inadequate ablation of the PV antrum. This may be used as a non-invasive marker to predict the outcome of AF.