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Page 2 of 13 Maurina et al. Mini-invasive Surg 2021;5:53 https://dx.doi.org/10.20517/2574-1225.2021.88

[3,4]
Anticoagulation has been shown to reduce the risk of embolization in AF . However, in patients with high
bleeding risk who are not candidates for anticoagulation, a different approach should be evaluated. Due to
its anatomical characteristics and low-flow state predisposing to blood stasis and thrombosis, most atrial
[5]
thrombi form in the LAA . For this reason, percutaneous and surgical techniques have been developed
over the years to exclude the LAA and prevent systemic embolization in AF. The purpose of this paper is to
make an overview of the current state of LAAO procedure, with a focus on available devices and future
perspectives.

ASSESSING THE BLEEDING AND STROKE RISK IN AF
The most feared complication of AF is systemic embolism, with ischemic stroke being the most clinically
relevant and catastrophic event. While anticoagulant therapy is effective in reducing embolization, bleeding
risk may equal or exceed embolic risk without anticoagulation in some patients .
[6]

Therefore, clinicians are used to estimate ischemic and bleeding risk with different scores that are useful to
choose the adequate management strategy. The CHA2DS2-VASc and HAS-BLED scores provide an
[7]
[8]
estimate of the risk of stroke and bleeding events, respectively. Current guidelines (both European and
American) [9-11] do not recommend antithrombotic treatment in patients with a CHA2DS2-VASc score = 0 in
males and = 1 in females, while anticoagulation is indicated for higher scores. Regarding bleeding risk,
modifiable risk factors in high-risk patients (HAS-BLED ≥ 3) should be addressed and flagged up for regular
follow-up with close INR monitoring or adjustment of the dose of anticoagulant medications, when
possible. Of note, high scores should not be used as a reason to withhold oral anticoagulation (OAC) if a
patient is considered eligible.

INDICATION FOR LAAO
For AF patients at high risk for ischemic stroke (CHA2DS2-VASc score ≥ 1 in males and ≥ 2 in females)
who should receive anticoagulation but for whom OAC is contraindicated, both European and American
guidelines give a IIb class recommendation for percutaneous LAAO to prevent systemic embolism [9,11] .
Patients with the following characteristics may be included in this category:

• Prior severe bleeding (e.g., intracranial hemorrhage without a reversible cause).

• Diagnosed coagulation defect related to hemorrhage.

• History of recurrent bleedings (e.g., genitourinary or gastrointestinal) and anemia.

• Poor compliance or intolerance to OAC.

Furthermore, LAAO may also have a role in patients who refuse antithrombotic therapy due to personal
preferences. While this population has not yet been extensively studied, future trials will focus on these
patients, and indications for LAAO may considerably enlarge.

Currently available devices
Percutaneous LAAO devices are based on three different principles: the plug, the pacifier, and the
ligation . While many different percutaneous devices are available in Europe, only two of them are
[12]
currently FDA approved. In addition, surgical LAA exclusion can be performed via thoracoscopy with the
AtriClip (FDA approved in 2010). The main characteristics of the current devices are summarized in
Table 1.