Pretreatment with Antithrombotic Agents During Radiofrequency Catheter Ablation: A Randomized Comparison of Aspirin Versus Ticlopidine

Abstract

D-dimer is a product of fibrin degradation and can serve as a biochemical marker of thrombus formation and reactive fibrinolysis. According to our previous observations, and as reflected by elevated plasma D-dimer levels, lesions produced by radiofrequency (RF) ablation have a thrombogenic effect. Pretreatment with combined aspirin and ticlopidine mitigates this thrombogenicity; however, the effect of either agent alone remains unknown. In this study, 59 patients undergoing RF ablation were randomized to pretreatment with aspirin (group I; n = 30) or ticlopidine (group II; n = 29) for 3 days prior to RF ablation. D-dimer levels were measured by enzyme immunoassay before and after the electrophysiologic study (EPS), and both immediately and at 48 hours after RF ablation. Results also were compared with those of 31 patients (nonrandomized group III) who had received both aspirin and ticlopidine. At all stages, D-dimer levels were higher in groups I and II when compared with group III. Baseline D-dimer (31+/-20 vs 24+/-13 vs 17+/-11 microg/L, respectively; P = 0.002) rose after EPS to higher levels in groups I and II (91+/-100 microg/L and 51+/-35 microg/L) compared with group III (31+/-17 microg/L; P = 0.001). After RF ablation, D-dimer levels increased in all groups, but this increase was much higher in groups I and II (214+/-210 microg/L and 201+/-222 microg/L) than in group III (74+/-60 microg/L; P = 0.005). At 48 hours, D-dimer levels decreased in all groups, but remained higher in groups I and II (91+/-100 microg/L and 95+/-99 microg/L) than in group III (35+/-31 microg/L; P = 0.009). There were no differences among the three groups in the number of RF ablation lesions or the duration of the RF ablation procedure. Pretreatment with aspirin or ticlopidine alone does not decrease the thrombogenic potential of RF ablation. Only combined therapy with aspirin and ticlopidine has a favorable effect, as reflected by the lower degree of D-dimer elevation.