Effectiveness of Left Atrial Appendage Exclusion Procedures to Reduce the Risk of Stroke: A Systematic Review of the Evidence

Abstract

Background-Atrial fibrillation is an important cause of cardioembolic stroke. Oral anticoagulants (OAC) reduce stroke risk but increase the risk of serious bleeding. Left atrial appendage (LAA) procedures have been developed to isolate the LAA from circulating blood flow, as an alternative to OAC. We conducted a systematic review of the benefits and harms of surgical and percutaneous LAA exclusion procedures. Methods and Results-We searched multiple data sources, including Ovid MEDLINE, Cochrane, and Embase, through January 7, 2015. Of 2567 citations, 20 primary studies met prespecified inclusion criteria. We abstracted data on patient characteristics, stroke, mortality, and adverse effects. We assessed study quality and graded the strength of evidence using published criteria. Trials found low-strength evidence that percutaneous LAA exclusion confers similar risks of stroke and mortality as continued OAC, but this evidence was limited to the Watchman device in patients eligible for long-term OAC. Observational studies found moderate-strength evidence of serious harms with a variety of percutaneous LAA procedures. There is low-strength evidence that surgical LAA exclusion does not add significant harm during heart surgery for another indication, but evidence on stroke reduction is insufficient. Conclusions-There is limited evidence that the Watchman device may be noninferior to long-term OAC in selected patients.Data on effectiveness of LAA exclusion devices is lacking in patients ineligible for long-term OAC. Percutaneous LAA devices are associated with high rates of procedure-related harms. Although surgical LAA exclusion during heart surgery does not seem to add incremental harm, there is insufficient evidence of benefit. (Circ Cardiovasc Qual Outcomes. 2016;9:395-405.

Adding left atrial appendage closure to open heart surgery provides protection from ischemic brain injury six years after surgery independently of atrial fibrillation history: the LAACS randomized study

“…Comparing our findings to available literature, it is generally accepted that there is very little evidence on the effects of surgical closure of the LAA [ 36 ]. A previous study from 2000 by Johnson et al showed no safety issues regarding LAACS among the 437 patients included, where of which 43 appendages were stapled and 391 were sutured.…”

“…A previous study from 2000 by Johnson et al showed no safety issues regarding LAACS among the 437 patients included, where of which 43 appendages were stapled and 391 were sutured. [ 37 ] In a recent systematic review of LAA closure, the authors concluded that there are no randomized clinical trials and that published evidence is insufficient to assess the benefits of LAACS but there is seemingly no adverse risk associated with the procedure [ 36 ].…”

Commentary: Carotid Artery Revascularization for Stroke Prevention

“…For instance, reproducible risk stratification models for nonvalvular AF have not only been developed and validated but also effectively disseminated as a useful everyday clinical practice tool (eg, the CHA 2 DS 2 -VASc and HAS-BLED score decision-making model 76 ), and the role of pharmacologic vs interventional stroke risk management in AF has been elucidated. 77,78 Urgent, multispecialty and large-scale endeavors, involving neurologists, vascular surgeons, radiologists, cardiologists, and angiologists are therefore greatly needed to close the embarrassing gap in prospectively validated evidence to determine the optimal management paths suitable for particular subsets of CS patients, particularly asymptomatic. 29 Nevertheless, until (and if) prospectively validated algorithms similar to the CHA 2 DS 2 -VASc score become available for asymptomatic CS, neurologists and vascular specialists should endeavor to incorporate 3 in their decision making the already identified increased-risk criteria 39 as per local feasibility.…”

To occlude or not? Left atrial appendage occlusion for stroke prevention in atrial fibrillation

“…Meta-analyses show low-strength evidence that LAA closure with Watchman device is associated with similar risk of stroke and mortality compared with warfarin 7. Of 4998 screened patients in the PROTECT AF trial, only 707 (14.1%) were finally randomised, which raises question about method utility and findings generalisability.…”

“…In addition, serious periprocedural adverse events were reported in 1.6–13.6% of patients 7. Finally, given the advantages of NOACs over warfarin, particularly the substantially lower risk of intracranial bleeds, RCTs comparing efficacy and safety of LAA occlusion versus NOACs are highly warranted.…”