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Association of Surgical Left Atrial Appendage Occlusion With Subsequent Stroke and Mortality Among Patients Undergoing Cardiac Surgery

Educational Objective
To learn the association of surgical left atrial appendage occlusion (LAAO) with subsequent risk of stroke and mortality.
1 Credit CME
Key Points

Question  Is surgical occlusion of the left atrial appendage (LAAO) during cardiac surgery associated with reduced risk of stroke or all-cause mortality?

Finding  In this retrospective cohort study of 75 782 patients undergoing cardiac surgery, concurrent surgical LAAO, compared with no surgical LAAO, was significantly associated with a lower risk of stroke (hazard ratio, 0.73) and mortality (hazard ratio, 0.71) among a propensity score–matched cohort of 8590 patients.

Meaning  Surgical LAAO in patients undergoing concurrent cardiac surgery was associated with reduced risk of subsequent stroke and all-cause mortality.


Importance  Surgical occlusion of the left atrial appendage (LAAO) may be performed during concurrent cardiac surgery. However, few data exist on the association of LAAO with long-term risk of stroke, and some evidence suggests that this procedure may be associated with subsequent development of atrial fibrillation (AF).

Objective  To evaluate the association of surgical LAAO performed during cardiac surgery with risk of stroke, mortality, and development of subsequent AF.

Design, Setting, and Participants  Retrospective cohort study using a large US administrative database that contains data from adult patients (≥18 years) with private insurance or Medicare Advantage who underwent coronary artery bypass graft (CABG) or valve surgery between January 1, 2009, and March 30, 2017, with final follow-up on March 31, 2017. One-to-one propensity score matching was used to balance patients on 76 dimensions to compare those with vs without LAAO, stratified by history of prior AF at the time of surgery.

Exposures  Surgical LAAO vs no surgical LAAO during cardiac surgery.

Main Outcomes and Measures  The primary outcomes were stroke (ie, ischemic stroke or systemic embolism) and all-cause mortality. The secondary outcomes were postoperative AF (AF within 30 days after surgery among patients without prior AF) and long-term AF-related health utilization (event rates of outpatient visits and hospitalizations).

Results  Among 75 782 patients who underwent cardiac surgery (mean age, 66.0 [SD, 11.2] years; 2 2091 [29.2%] women, 25 721 [33.9%] with preexisting AF), 4374 (5.8%) underwent concurrent LAAO, and mean follow-up was 2.1 (SD, 1.9) years. In the 8590 propensity score–matched patients, LAAO was associated with a reduced risk of stroke (1.14 vs 1.59 events per 100 person-years; hazard ratio [HR], 0.73 [95% CI, 0.56-0.96]; P = .03) and mortality (3.01 vs 4.30 events per 100 person-years; HR, 0.71 [95% CI, 0.60-0.84]; P < .001). LAAO was associated with higher rates of AF-related outpatient visits (11.96 vs 10.26 events per person-year; absolute difference, 1.70 [95% CI, 1.60-1.80] events per person-year; rate ratio, 1.17 [95% CI, 1.10-1.24]; P < .001) and hospitalizations (0.36 vs 0.32 event per person-year; absolute difference, 0.04 [95% CI, 0.02-0.06] event per person-year; rate ratio, 1.13 [95% CI, 1.05-1.21]; P = .002). In patients with prior AF (6438/8590 [74.9%]) with vs without LAAO, risk of stroke was 1.11 vs 1.71 events per 100 person-years (HR, 0.68 [95% CI, 0.50-0.92]; P = .01) and risk of mortality was 3.22 vs 4.93 events per 100 person-years (HR, 0.67 [95% CI, 0.56-0.80]; P < .001), respectively. In patients without prior AF (2152/8590 [25.1%]) with vs without LAAO, risk of stroke was 1.23 vs 1.26 events per 100 person-years (HR, 0.95 [95% CI, 0.54-1.68]), risk of mortality was 2.30 vs 2.49 events per 100 person-years (HR, 0.92 [95% CI, 0.61-1.37]), and risk of postoperative AF was 27.7% vs 20.2% events per 100 person-years (HR, 1.46 [95% CI, 1.22-1.73]; P < .001). The interaction term between prior AF and LAAO was not significant (P = .29 for stroke and P = .16 for mortality).

Conclusions and Relevance  Among patients undergoing cardiac surgery, concurrent surgical LAAO, compared with no surgical LAAO, was associated with reduced risk of subsequent stroke and all-cause mortality. Further research, including from randomized clinical trials, is needed to more definitively determine the role of surgical LAAO.

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Article Information

Corresponding Author: Xiaoxi Yao, PhD, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (yao.xiaoxi@mayo.edu).

Accepted for Publication: April 18, 2018.

Author Contributions: Dr Yao had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Yao, Holmes, Melduni, Johnsrud, Noseworthy.

Acquisition, analysis, or interpretation of data: Yao, Gersh, Melduni, Sangaralingham, Shah, Noseworthy.

Drafting of the manuscript: Yao, Sangaralingham, Noseworthy.

Critical revision of the manuscript for important intellectual content: Yao, Gersh, Holmes, Melduni, Johnsrud, Shah, Noseworthy.

Statistical analysis: Yao, Holmes.

Administrative, technical, or material support: Holmes, Sangaralingham, Shah, Noseworthy.

Supervision: Holmes, Melduni, Shah, Noseworthy.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.

Funding/Support: This study was funded by the Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery. Dr Melduni is supported by National Institutes of Health grant K01 (HL 135288).

Role of the Funder/Sponsor: The funder/sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

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