Association of Surgical Left Atrial Appendage Occlusion With Subsequent Stroke and Mortality Among Patients Undergoing Cardiac Surgery
Authors: Xiaoxi Yao, Bernard J. Gersh, David R. Holmes, Rowlens M. Melduni, Daniel O. Johnsrud, Lindsey R. Sangaralingham, Nilay D. Shah, Peter A. Noseworthy
Journal: JAMA (2018)

<h3>Importance</h3> 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). <h3>Objective</h3> To evaluate the association of surgical LAAO performed during cardiac surgery with risk of stroke, mortality, and development of subsequent AF. <h3>Design, Setting, and Participants</h3> 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. <h3>Exposures</h3> Surgical LAAO vs no surgical LAAO during cardiac surgery. <h3>Main Outcomes and Measures</h3> 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). <h3>Results</h3> 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];<i>P</i> = .03) and mortality (3.01 vs 4.30 events per 100 person-years; HR, 0.71 [95% CI, 0.60-0.84];<i>P</i> &lt; .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];<i>P</i> &lt; .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];<i>P</i> = .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];<i>P</i> = .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];<i>P</i> &lt; .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];<i>P</i> &lt; .001). The interaction term between prior AF and LAAO was not significant (<i>P</i> = .29 for stroke and<i>P</i> = .16 for mortality). <h3>Conclusions and Relevance</h3> 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.