1008-15 Effectiveness of Heparin for Prevention of Coagulation Factor Activation During Radiofrequency Catheter Ablation

Abstract

A major complication of radiofrequency catheter ablation is thromboembolism, although the mechanism underlying this is unknown. We compared coagulation factor activation during catheter ablation and diagnostic electrophysiologic study and sought to determine whether IV heparin is effective in preventing it. Fifty-five pts were prospectively studied: group I (28 pts) had diagnostic electrophysiologic study; group II (9 pts) had ablation without heparin; group III (18 pts) had ablation with heparin (8842 ± 1842 unit bolus + 1000 units/hr infusion). No differences were found in age, procedure time, or number of radiofrequency applications in group II vs. group III, Thrombogenesis was measured at the start (T0) and end of the electrophysiologic study or ablation procedure (T1), and the following morning (T2) using D-dimer (DD; ng/ml) and thrombin-antithrombin complex (TAT: ng/ml) assays. (Median values): Group I Group II Group III TAT DD TAT DD TAT DD T0 9.1 915 5.1 464 5.3 206 T1 20.0 1102 23.2 2107 8.6 627 T2 4.5 1016 10.6 627 7.6 720 DD increased in all groups at Tl and T2 (p < 0.05) with the largest increase in the ablation groups (II and III). Compared to baseline, TAT was increased only in Groups II and III at Tl (p < 0.05; Wilcoxon matched pairs signed ranks test); however, heparinized patients showed a smaller rise in TAT (p = 0004). TAT returned to baseline by T2 in all groups. 1. The magnitude of coagulation factor activation appears to be greater in the catheter ablation group compared to the electrophysiologic study group. 2. Coagulation factor activation may be reduced, but not eliminated, by conventional doses of IV heparin 3. Higher doses of heparin may be needed during catheter ablation to prevent thrombogenesis.