Stroke Prevention in Atrial Fibrillation: Atrial Appendage Closure

Abstract

The left atrial appendage (LAA) is the primary nonvalvular cause of cardioembolic stroke in patients with atrial fibrillation (AF). Warfarin and direct thrombin inhibitors such as dabigatran are presumed to prevent formation of LAA thrombus, and are first-line treatments to prevent ischemic stroke in AF. However, these medications carry many contraindications such as hemorrhage, and can interact with many drugs and supplements. Epicardial and endovascular techniques for occlusion of LAA are being explored, whether to mitigate the need for anticoagulation in patients at risk of bleeding or as a first-line therapy to reduce the risk of thromboembolic stroke. The purposes of this article are to 1) review the LAA structure and its potential contribution to ischemic stroke; 2) discuss the results of surgical and endovascular trials of LAA occlusion on risk of stroke and adverse events in AF patients; and 3) present early data on devices in development.

Percutaneous Endocardial Occlusion of Incompletely Surgically Ligated Left Atrial Appendage

“…Although the clinical significance of ISLL warrants further investigation, ISLL in patients with an elevated thromboembolic risk has likely the potential to harbor intracardiac thrombi and serve as a major threat for embolic events. Furthermore, it has been proposed that ISLL may actually be worse than no occlusion at all, given that reduced blood flow velocities in and out of ISLL may indeed promote a higher risk of thrombus formation . Consistent with this, patients 2 and 4 suffered embolic strokes shortly following surgical ligation of the LAA (within 3 weeks and 10 days, respectively).…”

The impact of CHADS2 score on late stroke after the Cox maze procedure

“…Numerous studies have shown that the LAA is an important source of potential emboli. 9,17 Moreover, the latest iteration of the CMP (the CMP IV), as well as previous iterations of the CMP, have been shown to achieve drug-free freedom from AF of at least 84% of patients at 2 years postoperatively. 18 …”

“…6–8 The efficacy of the CMP for decreasing stroke risk has been attributed to both its success at restoring sinus rhythm and the amputation or exclusion of the left atrial appendage (LAA). 9 …”

Oclusão do apêndice atrial esquerdo com o Amplatzer Cardiac Plug em pacientes com fibrilação atrial

“…Stroke prevention is a primary goal in AF treatment, since 87% of strokes are believed to be thromboembolic, and patients with AF, whether permanent or paroxysmal, have a five-fold risk of stroke in comparison to a matched population in sinus rhythm 2 . This risk increases with age, from 1.5% / year in the 50-59-yearold age group to 23.5% in the 80-89-year-old age group 1,3 . Accordingly, oral anticoagulation for stroke prevention in AF patients has a class I, level of evidence A recommendation 4 .…”