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Published on: February 26, 2013
Stroke Mechanism and Severity After Left Atrial Appendage Occlusion: Insights From the LAAOS III Randomized Clinical
Aristeidis H Katsanos1,2, Richard P Whitlock1,3, Emilie P Belley-Côté1,4
1Population Health Research Institute, and Hamilton Health Sciences, Hamilton, Ontario, Canada.
Insights
Surgical left atrial appendage occlusion (LAAO) in patients with atrial fibrillation (AF) undergoing cardiac surgery significantly lowers stroke risk. LAAO reduces cardioembolic strokes, stroke-related disability, and mortality.
Area of Science:
- Cardiology
- Neurology
- Medical Interventions
Background:
- Atrial fibrillation (AF) is a significant risk factor for stroke, often due to clots forming in the left atrial appendage (LAA).
- Surgical occlusion of the LAA (LAAO) during cardiac surgery is a strategy to mitigate this risk.
Purpose of the Study:
- To investigate the impact of LAAO on ischemic stroke subtypes and outcomes in patients with AF undergoing cardiac surgery.
- To analyze the effect of LAAO on functional recovery, mortality, and infarct characteristics after stroke.
Main Methods:
- A post hoc analysis of the randomized LAAOS III trial involving patients with AF and high stroke risk undergoing cardiac surgery.
- Comparison of outcomes between surgical LAAO plus standard care versus standard care alone.
- Assessment of stroke functional outcome (modified Rankin Scale), 30-day mortality, neuroimaging findings (cortical infarcts), and stroke etiology.
Main Results:
- LAAO was associated with reduced modified Rankin Scale scores at 7 days or discharge (OR, 0.80; 95% CI, 0.65-0.99).
- Participants receiving LAAO had lower 30-day mortality post-stroke (HR, 0.55; 95% CI, 0.31-0.97).
- LAAO reduced the incidence of cortical infarcts and presumed cardioembolic strokes compared to the no-LAAO group.
Conclusions:
- Surgical LAAO in AF patients undergoing cardiac surgery is linked to a decreased risk of cardioembolic stroke.
- LAAO improves functional outcomes and reduces mortality following stroke events.
- These findings support LAAO as a beneficial intervention for AF patients undergoing cardiac surgery.
Importance:
In the Left Atrial Appendage Occlusion Study III (LAAOS III), surgical occlusion of the LAA during cardiac surgery for patients with known history of atrial fibrillation (AF) substantially reduced the risk of stroke.
Objective:
To assess the impact of LAAO on ischemic stroke subtype and outcome.
Design, Setting, And Participants:
This was a post hoc exploratory analysis of the LAAOS III randomized clinical trial. Data were adjudicated from June 28, 2023, to November 29, 2023, and the main analyses took place from December 18, 2023, to April 29, 2024. The LAAOS III trial recruited participants from 105 centers in 27 countries between July 2012 and October 2018. Patients with AF and a CHA2DS2-VASc score of at least 2 undergoing cardiac surgery for other indications were included in the analysis.
Interventions:
Surgical LAAO plus standard care vs standard care alone.
Main Outcomes And Measures:
For strokes occurring during the trial, the functional outcome as measured by the modified Rankin Scale (mRS) score at day 7 or discharge, mortality, the presence of cortical infarcts, and the occurrence of infarcts of presumed cardioembolic origin were examined.
Results:
Of 4811 participants in the LAAOS III trial followed up for 3.8 years, 273 had a first ischemic stroke. The mean (SD) age of participants at the time of the first ischemic stroke was 75 (7) years, 104 were female (38%), and 169 were male (62%). Participants allocated to receive LAAO had reduced (common odds ratio [OR], 0.80; 95% CI, 0.65-0.99) mRS scores at 7 days or discharge and a lower risk for mortality at 30 days (16.5% vs 20.1%; hazard ratio [HR], 0.55; 95% CI, 0.31-0.97) after a stroke event. Participants allocated to LAAO had fewer cortical infarcts on neuroimaging (46.2% vs 61.3%; difference in proportions: -15.2%; 95% CI, -26.7% to -3.7%), as well as a lower proportion of ischemic strokes of presumed cardioembolic etiology when compared with ischemic strokes in the no-LAAO group (42.9% vs 57.9%; difference in proportions: -15.1%; 95% CI, -26.5% to -3.7%).
Conclusions And Relevance:
This study found that LAAO in patients with AF undergoing cardiac surgery was associated with a decreased risk of presumed cardioembolic stroke, reduced disability, and mortality from stroke. These findings underscore the benefit of LAAO for patients with AF undergoing cardiac surgery.
Trial Registration:
ClinicalTrials.gov Identifier: NCT01561651.
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