Cor Vasa 2002, 43(7-8):319-323

The risk of thromboembolic complications in patients with atrial flutter managed by catheter radiofrequency ablation: is anticoagulation therapy necessary?

Petr Neužil^1,*, Jiří Dostal¹, Miloš Táborský¹, Lucie Šedivá¹, Roman Vopálka², Petr Niederle¹

¹ Kardiologické oddělení

² Oddělení zdravotnické techniky, Nemocnice Na Homolce, Praha, Česká republika

Introduction:
Catheter radiofrequency ablation (RFA) has become, in the last decade, a rapidly developing method of non-pharmacological treatment of cardiac arrhythmias. In recent years, it has become the treatment of first choice in typical atrial flutter, with anatomically controlled line of RF energy delivery in the region of the cavotricuspid bridge.
The risk for thromboembolic complications in atrial flutter has long been rather underestimated, it was not until recently that several studies have demonstrated an increased incidence of thromboembolism, especially so in connection with cardioversion.


Method and group of patients:
Our study was designed to establish the risk of thromboembolic complication associated with RFA. Detailed data are lacking in the relevant literature.
We evaluated a total of 93 patients with atrial flutter undergoing cavotricuspid bridge RFA in our center. The patients were divided into three groups as to the type of drug therapy used prior to the intervention.
Group One included patients with previous long-term anticoagulant therapy with warfarin (n = 45), Group Two included individuals with antiaggregation therapy with anopyrin (n = 22); Group Three included patients without previous anticoagulant and antiaggregation therapy (n = 26).
RFA was undertaken in all patients, the number of RF applications was an average 20.8 ± 11 s, and average procedure time was 136 ± 37 minutes. The above three groups did not differ in baseline parameters.

Results:
No case of systemic embolism was observed in the period immediately after the RFA procedure or during one-year follow-up. One patient in group 3 (without antiaggregation and anticoagulation) developed clinically manifest pulmonary embolism 17 hours post-procedure.
Atrial fibrillation (AF) paroxysms were seen in 12 patients while undergoing RFA, directly related to programmed atrial pacing. The incidence of AF prior to RFA could be documented in 47 patients referred to RFA (more than 50% of the group).
Bidirectional cavotricuspid bridge conduction block was accomplished in 68 patients (73%) whereas block induction was assessed as incomplete in 18 (19%) patients. The procedure was evaluated was completely unsuccessful in 7 (8%) cases.
Atrial flutter recurrence was observed in 13 patients; of this number in all six cases of failed RFA. At least one AF episode was documented in 19 patients during follow-up.

Conclusion:
Cavotricuspid bridge RFA using the method of linear lesion creation is associated with very low thromboembolic complication rates, even in patients not using anticoagulation or antiaggregation therapy before the procedure.

Keywords: Catheter radiofrequency ablation; Atrial flutter; Atrial fibrillation; Thromboembolic complications

Published: July 1, 2002  Show citation