Introduction
Pulmonary vein isolation (PVI) is an effective rhythm control therapy
for atrial fibrillation (AF).1,2 However,
procedure-related complications still cannot be ignored and
thromboembolic complications remain a major limitation of AF ablation.
Patients undergoing AF ablation are at a higher risk of intra- and
post-procedural thromboembolic events; therefore, peri-procedural
anticoagulation is necessary. Since non-vitamin K oral anticoagulants
(NOACs) have been commonly used for stroke prevention of AF, recent
studies examined the peri-procedural management of NOACs in patients
scheduled to undergo radiofrequency catheter ablation (RFCA) for
AF.3-6 Based on these results, the performance of the
ablation procedure without interruption of oral anticoagulant (OAC) is
recommended for patients undergoing AF ablation who have been
therapeutically anticoagulated with OAC including
NOACs.7
In terms of intra-procedural anticoagulation management, unfractionated
heparin should be administered prior to or immediately following
transseptal puncture and dose adjustment is recommended to achieve and
maintain an activated clotting time (ACT) of at least 300
s.8 However, this recommendation is based on results
of studies conducted using vitamin K antagonists (VKA) in a setting of
point-by-point AF ablation. Moreover, the majority of recommendations
were made based on results from studies evaluating the efficacy and
safety of RFCA and not on diverse modalities for AF ablation. Several
modalities use different energy sources to achieve PVI. Cryoballoon
ablation (CBA), a balloon-based single shot technique for PVI, has shown
the similar efficacy and safety profile with a relatively short learning
curve compared to RFCA.9-13 Previous randomized
clinical trials (RCTs) demonstrated that CBA had a shorter procedure
time and lower rates of re-hospitalization, cardioversion, and repeat
ablation than RFCA. Therefore, the use has exponentially increased.
The use of adequate peri-procedural anticoagulation regimens that strike
a balance between the benefit of blood thinning and the risk of bleeding
is essential in patients undergoing AF ablation. However, no data have
been available in terms of anticoagulation strategy during CBA for
patients who received uninterrupted NOACs. We aimed to investigate the
safety of a simple anticoagulation
strategy using a single bolus administration of heparin without ACT
monitoring compared to that of the conventional approach using
ACT-guided heparin administration in patients who underwent CBA with
uninterrupted NOACs.