Embolic events and char formation during pulmonary vein isolation in patients with atrial fibrillation: impact of different anticoagulation regimens and importance of intracardiac echo imaging

J Cardiovasc Electrophysiol. 2005 Jun;16(6):576-81. doi: 10.1111/j.1540-8167.2005.40480.x.


Thromboembolic events are important complications of pulmonary vein isolation (PVI) procedures, occurring in up to 2.8% of patients. In this study, we report the incidence of char formation and embolic events with different anticoagulation protocols prospectively changed to reduce such complication.

Methods: A total of 785 patients (mean age: 54 years, 83.5% male) underwent catheter-based PVI for treatment of drug refractory, symptomatic atrial fibrillation (AF). PVI was performed utilizing different strategies including radiofrequency (RF) using temperature control energy delivery and RF using intracardiac echocardiography (ICE)-guided power titration. Patients were divided based on the anticoagulation protocol into three groups: in group 1 (194 patients), activation coagulation time (ACT) was maintained between 250 and 300 seconds; in group 2 (180 patients), ACT was maintained between 300 and 350 seconds plus the IV infusion of eptifibatide (135 microg/kg bolus + 0.5 microg/kg/min); and in group 3 (411 patients), ACT was maintained between 350 and 400 seconds.

Results: Char formation was detected in 69 patients of group 1, 5 of group 2, and 8 of group 3. An embolic event was observed in 7 patients of group 1, 3 of group 2, and 2 of group 3 (P = 0.01; group 1 vs group 3). Higher degree of anticoagulation with heparin was associated with a reduced incidence of embolic events even after removing the patients undergoing ICE-guided ablation (P = 0.04).

Conclusion: More aggressive anticoagulation with heparin reduced periprocedural embolic events. The use of platelet inhibition does not have incremental beneficial effect. None of the anticoagulation protocol abolished char formation.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Anticoagulants / therapeutic use*
  • Atrial Fibrillation / diagnostic imaging
  • Atrial Fibrillation / surgery*
  • Catheter Ablation / adverse effects
  • Catheter Ablation / methods*
  • Clinical Protocols
  • Echocardiography, Transesophageal
  • Female
  • Heparin / therapeutic use*
  • Humans
  • Intraoperative Complications / diagnostic imaging
  • Intraoperative Complications / prevention & control*
  • Jugular Veins / surgery
  • Male
  • Middle Aged
  • Prospective Studies
  • Pulmonary Veins / physiopathology*
  • Risk Factors
  • Thromboembolism / diagnostic imaging
  • Thromboembolism / etiology
  • Thromboembolism / prevention & control*


  • Anticoagulants
  • Heparin