April 12, 2005
View Full PaperIncreased Intensity of Anticoagulation May Reduce Risk of Thrombus During Atrial Fibrillation Ablation Procedures in Patients with Spontaneous Echo Contrast
Structured PICO
Does increased intensity of heparin anticoagulation (ACT >300 seconds) reduce left atrial thrombus formation during atrial fibrillation ablation compared to standard intensity (ACT 250-300 seconds)?
P
Population
511 patients (age 56 +/- 10 years) undergoing pulmonary vein ostial isolation/ablation using radiofrequency energy for atrial fibrillation, including 179 patients with spontaneous echo contrast (SEC) detected by intracardiac echocardiography.
I
Intervention
Heparin anticoagulation to achieve activated clotting time (ACT) >300 seconds confirmed at 30-minute intervals (n=217).
C
Comparator
Heparin anticoagulation to achieve activated clotting time (ACT) 250-300 seconds confirmed at 30-minute intervals (n=294).
O
Outcome
Left atrial (LA) thrombus formation detected by intracardiac echocardiography (ICE) during the procedure.surrogate
Targeting a higher ACT (>300 seconds) during atrial fibrillation ablation significantly reduces the risk of left atrial thrombus formation, particularly in patients with spontaneous echo contrast.
Abstract
INTRODUCTION: A 10% incidence of left atrial (LA) thrombus formation has been detected using intracardiac echocardiography (ICE) imaging monitoring during LA ablation for atrial fibrillation (AF). The aim of this study was to determine if the intensity of anticoagulation reduces LA thrombus formation during pulmonary vein isolation procedure in patients with AF and spontaneous echo contrast (SEC). METHODS AND RESULTS: We studied 511 patients (age 56 +/- 10 years) undergoing pulmonary vein ostial isolation/ablation using radiofrequency energy. SEC was detected in 179 of 511 patients with ICE imaging before dual transseptal catheterization. All patients were anticoagulated with heparin to achieve activated clotting time (ACT) 250-300 seconds (group I) or >300 seconds (group II) confirmed at 30-minute intervals. SEC was detected in 49/294 (16.7%) patients in group I versus 130/217 (59.9%) in group II (P 300 seconds) during LA ablation for AF may prevent LA thrombus formation especially in patients with SEC.