Anticoagulation Intensity during Appendage Occlusion: Lessons from Silent Cerebral Embolism

Area of Science:

• Cardiology
• Neurology
• Interventional Radiology

Background:

• Endovascular left atrial appendage occlusion (LAAO) procedures carry a high risk of peri-procedural silent cerebral embolism (SCE).
• Current expert consensus recommends a lower activated clotting time (ACT) target for LAAO compared to atrial fibrillation (AF) ablation.
• The optimal ACT threshold for minimizing SCE during LAAO remains unclear.

Purpose of the Study:

• To investigate if increasing the target ACT level during LAAO to match AF ablation guidelines (≥300 s) can reduce the incidence of SCE.
• To evaluate the safety and efficacy of a higher ACT target in LAAO procedures.

Main Methods:

• A prospective observational cohort study involving consecutive AF patients undergoing LAAO.
• Patients were divided into two groups: one with a target ACT of ≥250 s (group 250) and another with a target ACT of ≥300 s (group 300).
• Cerebral magnetic resonance imaging was performed before and after LAAO to detect SCE.

Main Results:

• After inverse probability of treatment weighting (IPTW), the group 250 (lower ACT target) showed a significantly higher incidence of SCE compared to group 300 (higher ACT target) (IPTW p = 0.038).
• A stable high ACT pattern was associated with a decreased risk of SCE.
• No significant differences in SCE incidence were observed with other ACT change patterns.

Conclusions:

• Maintaining a stable peri-procedural ACT of ≥300 s during LAAO can decrease the risk of SCE.
• This higher ACT target did not lead to an increase in major bleeding events.
• Optimizing ACT management during LAAO is a viable strategy to enhance patient safety.