Abstract 13988: Novel Quantitative Assessment of Whole Blood Thrombogenicity in Patients Treated With Anticoagulants Undergoing Radiofrequency Catheter Ablation for Atrial Fibrillation

Introduction: Non-vitamin K antagonist oral anticoagulants (NOACs) are equivalent to warfarin in preventing thromboembolism in patients with atrial fibrillation (AF). Recently, Total Thrombus-formation Analysis System (T-TAS) was developed as an easy-to-use system for quantitative analysis of thrombus formation using microchips with thrombogenic surfaces (collagen, PL chip; collagen plus tissue factor, AR chip). Hypothesis: We evaluated the efficacy and safety of NOACs using the T-TAS in AF patients undergoing radiofrequency catheter ablation (RFCA). Methods: After exclusion of 19 from 121 consecutive patients undergoing RFCA for AF, the remaining 102 patients were divided into two groups; AF patients treated with warfarin (n=28), and NOACs (n=74). Blood samples obtained on the day (anticoagulant-free point), 3 days and 1 month after RFCA were used in T-TAS to compute the thrombus formation area under the curve (AUC) (PL24-AUC10, AUC for PL chip; AR10-AUC30, for AR chip). Results and Conclusion: The AR10-AUC30 and PL24-AUC10 levels were identical between the warfarin and NOACs groups on the day of RFCA (1708.5±162.1 vs 1757.5±138.0 in AR10-AUC30, p=0.13 and 389.1±95.5 vs 391.7±76.0 in PL24-AUC10, p=0.94, respectively). AR10-AUC30, but not PL24-AUC10 levels, was significantly lower in warfarin and NOACs groups at 3 days and 1 month after RFCA. Multiple logistic regression analysis identified AR10-AUC30 levels on the day of RFCA as a significant predictor of bleeding events in the period of three months after RFCA [odds ratio (OR) 20.6; 95% confidence interval (95%CI): 2.46 to 172.6; p=0.005]. Receiver-operating characteristic analysis showed that AR10-AUC30 levels on the day of RFCA significantly predicted bleeding events [AUC 0.849 (95%CI: 0.719-0.979; p