title: Periprocedural stroke risk in patients undergoing catheter ablation for atrial fibrillation on uninterrupted warfarin.
abstract: BACKGROUND
  Catheter ablation is an effective treatment for symptomatic individuals with atrial fibrillation (AF) but is associated with a risk of periprocedual stroke. Recent data suggest that this risk may be abolished if catheter ablation is performed with uninterrupted warfarin (UW). We sought to compare the incidence, severity and timing of periprocedural stroke between 2 periprocedural anticoagulation protocols: bridging low-molecular-weight heparin (LMWH) and UW.
  
  
  RESULTS
  Periprocedural stroke (≤14 days) was assessed in 2,855 ablations performed in 1,813 patients. Thromboembolic stroke occurred in 11/1,653 (0.7%) procedures with bridging LMWH and in 5/1,202 (0.4%) procedures on UW (P = 0.5). Four of the 5 strokes (80%) on UW occurred despite a therapeutic INR and a mean activated clotting time of ≥300 seconds and 4/5 strokes (80%) occurred in patients with a CHADS2 score of 0. Eleven of 16 (69%) strokes overall occurred within 24 hours of the procedure. All 4 strokes resulting in major neurological deficit occurred in the LMWH group. Major bleeding complications occurred in 6.0% of patients in the bridging LMWH group compared to 4.0% in the UW group (P = 0.02).
  
  
  CONCLUSIONS
  In contrast to existing data, periprocedural stroke still occurs despite therapeutic anticoagulation throughout the operative period. The optimal strategy to protect patients against thromboembolic stroke remains unclear.
authors.affiliation: Barts Health NHS Trust, London, UK.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Page
authors.forename: Neil
authors.initials: N
authors.lastname: Herring
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Hunter
authors.forename: Emma
authors.initials: E
authors.lastname: Withycombe
authors.forename: Matthew
authors.initials: M
authors.lastname: Lovell
authors.forename: G
authors.initials: G
authors.lastname: Wali
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Betts
authors.forename: Yaver
authors.initials: Y
authors.lastname: Bashir
authors.forename: Mehul
authors.initials: M
authors.lastname: Dhinoja
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Earley
authors.forename: Simon C
authors.initials: SC
authors.lastname: Sporton
authors.forename: Kim
authors.initials: K
authors.lastname: Rajappan
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schilling
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000453:epidemiology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019990:Perioperative Care / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: anticoagulation; atrial fibrillation; catheter ablation; stroke; warfarin