INTRODUCTION
Atrial fibrillation (AF) is a common supraventricular tachyarrhythmia
caused by uncoordinated atrial activation and associated with an
irregularly irregular ventricular response 1-4. The
causes of AF include underlying structural heart disease, metabolic
disorders, endocrine diseases, and certain medications1-4. The prevalence of AF is approximately 1%-2% in
the general population in developed countries 1-6.
Patients with AF are often at a significantly increased risk of
thromboembolism and, in particular, stroke 1-4. Most
patients with atrial fibrillation are at increased risk of stroke and
should receive thromboembolic prophylaxis in order to lower that risk1-4. The risk of thromboembolism can be significantly
reduced by appropriate use of antithrombotic therapy but at a somewhat
increased risk of bleeding 1-4.
Left atrial appendage closure (LAAC) has emerged as a valid
non-pharmacological option for the prevention of stroke in patients with
nonvalvular AF and contraindications to an indefinite oral
anticoagulation (OAC) therapy 2. Post-procedural
antithrombotic therapy is usually administered to prevent device-related
thrombi (DRT) and subsequent thromboembolic events until device
endothelialization 7. Nevertheless, each regimen
carries a certain risk of bleeding complications. The optimal drug
regimen and duration following LAAC with the Watchman occluder (Boston
Scientific, Marlborough, MA, US) is still under investigation. As a
consequence, various post-procedural anticoagulation strategies are
adopted among centers 7, 8.
In the randomized PROTECT-AF and PREVAIL trials, the patients received a
vitamin K antagonist (VKA) plus aspirin for 45 days, followed by dual
antiplatelet therapy (DAPT) for 4.5 months in patients eligible for OAC
after Watchman LACC 9, 10. Subsequent studies showed
that DAPT for variable durations was an effective and safe alternative
to warfarin after Watchman implantation in large real-world registries11, 12. A single-center registry reported the
feasibility of a shortened 6-week DAPT 13. In the
multicenter EWOLUTION registry, patients on non-vitamin K oral
anticoagulants (NOACs) had the lowest bleeding rate, without an increase
in DRT or stroke rates 14. Nevertheless, the most
optimal strategy remains to be defined.
This post hoc analysis of a dual-center prospective observational study
examined the incidence rates of non-procedure-related complications
including death, thromboembolic events, and bleeding events in patients
who received a 3-month DAPT regimen vs. 6-week anticoagulation plus
aspirin followed by a 4.5-month DAPT (ACT regimen) over a 12-month
follow-up period after successful LAAC. In addition, the associated risk
factors for net clinical benefit and clinically relevant bleedings were
examined.