Left Atrial Appendage and Closure

Abstract

Abstract-Patients with nonvalvular atrial fibrillation have a 4-to 5-fold increase in strokes and that rhythm may be responsible for 15% to 20% of all strokes, particularly in the elderly. In this setting, thrombus in the left atrial appendage has been found to be the source of stroke in 90% of cases. Although oral anticoagulants have been found effective in reducing stroke rates, for a variety of issues, they may only be used in 40% to 50% of patients at increased risk for stroke. Given pathophysiology of stroke, site-specific therapy directed at left atrial appendage occlusion has been now studied for stroke prevention, and one device is FDA approved (Watchman). A meta-analysis of 2 randomized clinical trials and 2 registries with this device documented the following: (1) patients receiving the device had significantly fewer hemorrhagic strokes (hazard ratio 0.22, P=0.004); (2) a significant reduction in cardiovascular or unexplained death (hazard ratio 0.48, P=0.004); (3) more ischemic strokes in the device group; however, when periprocedural events were excluded, the difference was not significant; and (4) a significant reduction in nonprocedural bleeding with the device (hazard ratio 0.51, P=0.006) versus control. At present, the only device approved in the United States is indicated in patients with nonvalvular atrial fibrillation with acceptable anatomy who are at increased risk for stroke and would be candidates for anticoagulation in whom there is concern about the risk/benefit ratio for chronic anticoagulation. Unresolved issues include optimal patient selection criteria, the role of devices in patients in whom anticoagulation is contraindicated, and the relative role of novel oral anticoagulants versus the device which has not been tested in randomized trials. (Circ Cardiovasc Interv. 2016;9:e002942.

Arrhythmogenecity and thrombogenicity of the residual left atrial appendage stump following surgical exclusion of the appendage in patients with atrial fibrillation

“…Our main findings were the following: (1) Residual stump was present in the majority (86.2%) of the post-Maze and postclip patients screened;(2) firing from the LAA stump was detected in 87.3% of cases;(3) electrical isolation of the stump resulted in higher success rate at long-term follow-up; (4) rate of TE events after discontinuation of OAC was very low in the study population; and (5) presence of smoke in LA was associated with TE events.The LAA is derived from the embryonic LA that is formed mainly by the adsorption of the primordial PVs and their branches 10. Our main findings were the following: (1) Residual stump was present in the majority (86.2%) of the post-Maze and postclip patients screened;(2) firing from the LAA stump was detected in 87.3% of cases;(3) electrical isolation of the stump resulted in higher success rate at long-term follow-up; (4) rate of TE events after discontinuation of OAC was very low in the study population; and (5) presence of smoke in LA was associated with TE events.The LAA is derived from the embryonic LA that is formed mainly by the adsorption of the primordial PVs and their branches 10.…”

“…Our main findings were the following: (1) Residual stump was present in the majority (86.2%) of the post-Maze and postclip patients screened;(2) firing from the LAA stump was detected in 87.3% of cases;(3) electrical isolation of the stump resulted in higher success rate at long-term follow-up; (4) rate of TE events after discontinuation of OAC was very low in the study population; and (5) presence of smoke in LA was associated with TE events.The LAA is derived from the embryonic LA that is formed mainly by the adsorption of the primordial PVs and their branches 10. Furthermore, it is well known that most of the left atrial thrombi in AF patients form in the LAA 3. Furthermore, it is well known that most of the left atrial thrombi in AF patients form in the LAA 3.…”

“…1 Failure of the fibrillating atrium to contract properly results in stasis and thrombus formation in the appendage. 3 These observations led to the concept of LAA exclusion via surgical amputation or complete obliteration of the appendage with clips or other occlusion devices with the aim to reduce the risk of thromboembolic (TE) events in these patients. 3 These observations led to the concept of LAA exclusion via surgical amputation or complete obliteration of the appendage with clips or other occlusion devices with the aim to reduce the risk of thromboembolic (TE) events in these patients.…”

“…3 These observations led to the concept of LAA exclusion via surgical amputation or complete obliteration of the appendage with clips or other occlusion devices with the aim to reduce the risk of thromboembolic (TE) events in these patients. 3 Of note, LAA is not only responsible for thrombus formation, but as evidenced by recent studies, it is also a common site for ectopic foci that initiate and maintain AF. 4 Thoracoscopic exclusion of the LAA with clips with or without surgical ablation for AF is another widely used treatment option.…”

Transseptal puncture for structural heart intervention: an old technique with new indications

“…The transseptal approach is by far the most frequently used 27. The location of TSP is somewhat dependent on the particular characteristics of the device to be implanted in order to facilitate coaxial alignment and reduce the risk of complications and embolisation.…”