Atrial fibrillation ablation using open-irrigated tip radiofrequency: Experience with intraprocedural activated clotting times ≤210 seconds

BackgroundAtrial fibrillation (AF) ablation procedures generally use intraprocedural activated clotting time (ACT) of >300–350 seconds to prevent thromboembolic events.ObjectiveTo evaluate bleeding and thromboembolic procedural complications in patients with symptomatic AF undergoing ablation procedures with low intraprocedural ACT.MethodsWe examined a subset of 372 of 2334 (15.9%) AF ablation procedures using open-irrigated tip radiofrequency catheters at 50 W, interrupted oral anticoagulation, and a target ACT of 225 seconds, with average ACT ≤210 seconds.ResultsThere were 372 ablation procedures in 339 patients with average ACT ≤210 seconds. Patient demographic characteristics were as follows: age 60.9 ± 9.4 years, men 269 (79.3%), left atrial (LA) size 4.27 ± 0.65 cm, prior stroke/transient ischemic attack 24 (7.1%), CHADS2 score 0.94 ± 0.98, and CHA2DS2-VASc score 1.53 ± 1.35. AF type was categorized as paroxysmal in 107 (31.6%), persistent in 200 (59.0%), and long-standing persistent in 32 (9.4%). Procedural and LA times were 119 ± 26 and 82 ± 24 minutes. Patients underwent preprocedure transesophageal echocardiography. The heparin bolus (8738 ± 2823 units, 93.4 mg/kg) was given after LA access, and the maintenance infusion was 1000 units/hour via a single transseptal sheath with subsequent adjustments based on ACT values. The average ACT was 202 ± 7.5 seconds per procedure, with 116 patients with average ACT <200 seconds and 16 patients with all ACTs