Influences Of RFCA On The Hemostatic System In Patients And Prevention Of Antiplatelet Therapy

BackgroundOver the past several years radiofrequency (RF) catheter ablation has become a standard therapy for many tachyarrhythmias. Although the procedure carries a low risk of cardiac perforation, in advertent AV nodal block, and femoral vascular complications, the principle limitation of the procedure is the risk of thromboembolism particularly when ablation is performed in the left side of the heart. The ongoing development of the catheter maze procedure for the treatment of atrial fibrillation, which currently involves the creation of extensive linear lesions, further raises the concern of thromboembolic risk. Several large studies reported thromboembolic complication at an incidence of 0.6%. In animal experiments, lesions with endocardial thrombus formation have been described with an incidence of mural thrombus as high as 30%. The above observations generated an interest in the mechanism and preventive measure of thremboembolic complication of RF ablation. Based on the available data, the exact cause of thromboembolic phenomenon after ablation is yet unknow. Methods: 88 hospitalized patients(male 45,female 43) from September, 2001 to March, 2002 were enrolled in our study. These patients under going RF ablation for supraventricular tachycardia(n=86) or idiopathic ventricular tachycardia(n=2) who were randomly divided into four groups. No patients in graup I (n=20) was undergoing antiplatelet therapy before RFCA, but these patients immediately took aspirin after RECA. Another groups were received pretreatment with either aspirin 0.3 daily (n=23 group II ) or clopidogrel75mg daily (n=22 groupIII) for 3 days before the procedure. The first sample (baseline) was drawn from the antecubital vein at the initial stage of admission.The second sample (pre-EPS) was drawn after femoral and internal jugularvenous sheath insertions. Blood was drawn before (pre-RF) , at the end of (post-RF) , and 24 hours after the procedure. Specimens were usilized for theanalysis of plasma GMP-14(k D-dimer and vWF.Results1. All the time, the concentrations of GMP-140 in group I were kept on a higher level after sheath insertions. At the pre-EPS and post-RF points, the concentrations in group I were 30.41 + 5.67 and 60.40+12.79 ng/ml per patient (P<0.05) , respectively. But the concentrations were kept on a lower level in groupIL III, especially IV compared with group I except baseline point (PO.05) .2. The concentrations of D-dimer in group I were always kept on a higher level after sheath insertions. At the pre-EPS and post-RF points, the concentrations in group I were 0.58 + 0.22mg/L ^ 1.50 + 0.56mg/L(P<0.05) separately. But the concentrations were kept on a lower level in group IK UK especially IV compared with group I except baseline point (PO.05) .3. The concentration of vWF was significantly increased at the pre-EPS point in all groups (P<0.05) and at the past-RF point except group II, IV(P<0.05) . VWF rose lightly at the end of the RF procedure in group II, IV (P<0.05) .VWF kept on a higher level at the end of the RF procedure in all the groups.4. No relation was observed between the changes of plasma GMP-140^ D-dimer^ vWF and either cumulative energy . the time of energyapplications .the number of energy applications ,the duration of the procedure or cTnl.ConclusionsOur data suggest that tissue injury by ablation results in damage of the endothelium. Radiofrequency ablation induces a prethrombotic state. Pretreatment with antiplatelet therapy should decrease the thrombogenic potential of RF ablation. Combined therapy with aspirin and clopidogrel has a favorable effect, as reflected by the lower degree of GMP-140 and D-dimer elevation. Aspirin might reduce the plasma vWF level.