title: Thromboembolic risk of patients referred for radiofrequency catheter ablation of typical atrial flutter without prior appropriate anticoagulation therapy.
abstract: BACKGROUND
  Radiofrequency catheter ablation of isthmus dependent atrial flutter is considered the therapy of choice. There is, however, controversy with regard to the thrombogenicity of atrial flutter in comparison with atrial fibrillation.
  
  
  METHODS
  Consecutive patients scheduled for catheter ablation of documented typical atrial flutter receiving insufficient (INR < 2.0) or no anticoagulation during the three weeks preceding the procedure underwent multiplane transesophageal echocardiography (TEE). Patients with exclusive documentation of atrial flutter were classified as group I, whereas patients with additional documentation of atrial fibrillation were classified as group II.
  
  
  RESULTS
  The study included 201 patients, 62 of whom were not on therapeutic anticoagulation (mean age 64 +/- 9 years, 87% men). In 10 of these 62 patients (16%), TEE detected a left atrial (LA) appendage thrombus in 4, or dense spontaneous echo contrast (SEC) in 6 patients. Comparison of patients with versus without SEC or thrombus, revealed a higher incidence of valvular heart disease (60% vs 26%, P = 0.05), but no differences with respect to age, gender, LA diameter, left ventricular end-diastolic diameter, or left ventricular ejection fraction. The incidence of positive TEE findings in group I was 1 in of 36 versus 9 of 26 in group II (3% vs 35%, P < 0.001), and the relative risk for thromboembolism in group II versus group I was 12.5 (95% CI: 3-55, P < 0.001).
  
  
  CONCLUSIONS
  There is a significant risk for thromboembolism in patients referred for ablation of typical atrial flutter who have not been appropriately anticoagulated.
authors.affiliation: J.W. Goethe University, Frankfurt, Germany.
authors.forename: Gerian C
authors.initials: GC
authors.lastname: Grönefeld
authors.forename: Florian
authors.initials: F
authors.lastname: Wegener
authors.forename: Carsten W
authors.initials: CW
authors.lastname: Israel
authors.forename: Claudius
authors.initials: C
authors.lastname: Teupe
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Hohnloser
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants